NON CARIOUS LESIONS

Prevalence of tooth loss
Tooth wear and causes
Tooth wear indices
Classification of tooth wear
Non carious cervical lesions include attrition, abrasion, abfraction, erosion and their combined lesion
developmental defects
resorption
trauma and fractures

1. NON – CARIOUS LESIONS

2. CONTENTS INTRODUCTION DEFINITION PREVALENCE OF TOOTH SURFACE LOSS CLINICAL MEASUREMENT OF TOOTH WEAR NON – CARIOUS CERVICAL LESIONS ATTRITION ABRASION ABFRACTION EROSION MANAGEMENT OF WORN DENTITION COMBINED LESIONS

3. DEVELOPMENTAL DEFECTS LOCALIZED NON – HEREDITARY ENAMEL HYPOPLASIA LOCALIZED NON – HEREDITARY ENAMEL HYPOCALCIFICATION LOCALIZED NON – HEREDITARY DENTIN HYPOPLASIA LOCALIZED NON – HEREDITARY DENTIN HYPOCALCIFICATION AMELOGENSIS IMPERFECTA DENTINIGENESIS IMPERFECTA TRAUMA AND FRACTURES RESORPTION CONCLUSION REFERNCES

4. Gradual loss of tooth structure occurs throughout the life, most often it is so slow that it rarely poses any problem to the patient However, pathological loss of tooth structure due to non-carious reasons can produce unacceptable esthetics, compromise oral functions, cause pain and sensitivity and negatively impact quality of life. These lesions are difficult to diagnose and treat successfully as the loss is exhibited in different patterns and on different surfaces of teeth for varying types of tooth surface loss INTRODUCTION

5. Determining the etiology and preventing further tooth surface loss, which requires using proper preventive methods, good management and the appropriate restorations is necessary for the successful management of non-carious lesions

6. DEFINITION ‘ Tooth surface loss’ or 'tooth wear ' refers to the pathological loss of tooth tissue by a disease process other than dental caries - Eccles, 1982 “Non carious tooth tissue loss” is defined as surface loss due to a disease process which does not involve bacteria. Pual A Brunton ,Decision making in Operative Dentistry “Non-carious cervical lesions (cervical wear)” are defined as the loss of tooth substance at the cemento -enamel junction - Mair, 1992

7. PREVALENCE OF TOOTH WEAR The Adult Dental Health Survey of 2009 reported that tooth wear extending into the dentin with over three quarters (77%) of dentate adults showing tooth wear in the anteriors . However, 15% showed moderate wear and 2% with severe wear. The Child Dental Health Survey of 201 3 identified that 21 % of 15- year-olds had evidence of erosion affecting the palatal surfaces of their permanent incisors (less when compared to the survey on 1993 – 32%) The prevalence of tooth wear is likely to escalate as life expectancy continues to increase. Adult Dental Health Survey 2009: Common oral health conditions and their impact on the population. British Dental Journal, 2012

8. Although decay is the usual cause of tooth destruction necessitating operative procedures , it has been estimated that 25% of tooth destruction does not originate from a carious process

9. A. Warreth et al. Tooth surface loss: A review of literature. Saudi Dental Journal. 2019

10. Physiological Tooth Surface Loss It occurs as a result of mastication and adjustment, which is required for the teeth to function correctly Physiological TSL may also occur at interproximal tooth surfaces due to friction between the adjacent teeth (Davies et al., 2002, Kaidonis , 2008) . P athological Tooth Surface Loss It represents unacceptable levels of dental hard tissue loss Etiology - multifactorial It is characterized by abnormal destruction, which may require treatment ( Van’t Spijker et al., 2009; Bartlett et al., 2011)

11. Pathological TSL is considered to be a common clinical finding in both children and adults, and its prevalence increases with age This prevalence was found to increase from 3% at the age of 20 years to 17% at the age of 70 years ( Van’t Spijker et al., 2009) The increase in prevalence of moderate tooth wear in adults is of little concern but, younger age groups affected by moderate and severe tooth wear may warrant some attention

12. CLINICAL MEASUREMENT OF TOOTH WEAR Tooth Wear I ndices (TWI) have been designed to identify increasing severity and extent of the lesions They are usually numerical. Some record lesions on an aetiological basis (e.g. erosion indices), others record lesions irrespective of aetiology (tooth wear indices);

13. SMITH AND KNIGHT TOOTH WEAR INDEX (TWI) - 1984

14. Smith and Knight Index - a comprehensive system whereby all four visible surfaces (buccal, cervi cal, lingual and occlusal–incisal) of all teeth present are scored for wear, irrespective of how it occurred. T his index was the first one designed to measure and monitor multifactorial tooth wear; This index avoids the confusion associated with terminology and translation or differences in opinion for diagnosis of aetiology based on clinical findings Most commonly used but has limitations such as Rely only on the ability of clinician to visually identify exposed dentin ( interexaminer bias) Does not relate etiology to the outcome of wear seen on the teeth. This makes it inaccurate to provide a complete picture of the clinical problem Time consuming Full use of the index as a research tool is not feasible without computer assistance Bardsley et al. The evolution of tooth wear indices. Journal of clinical oral investigation. 2008

15. SIMPLIFIED SCORING CRITERIA FOR TOOTH WEAR INDEX - Bardsley et al , 2004

16. NON – CARIOUS CERVICAL LESIONS (NCCLs)

17. ATTRITION It is defined as physiological wearing away of tooth as a result of tooth to tooth contact as in mastication - Shafer It may be defined as surface tooth structure loss resulting from direct frictional forces between contacting teeth - Marzouk Attrition is defined as the mechanical wear of incisal and occlusal surfaces as a result of functional or parafunctional movements of mandible (Tooth-to tooth contact) - Sturdevant Every in 1972 , described it is wear caused by endogenous material such as microfine particles of enamel prisms caught between two opposing tooth surfaces.

18. Its an Age dependent continuous process U sually physiologic. Any contacting tooth surface is subjected to the attrition process, beginning from the time it erupts in the mouth and makes contact with reciprocating tooth surface. Mostly affects occlusal surfaces of the teeth It also includes the proximal surface wear at the contact area because of the physiologic tooth movement Accelerated by parafunctional movements such as bruxism Men > women

19. AGEING AGGRESSIVE TOOTHBRUSING

20. There are three theories regarding the etiology of attrition: • Functional theory • Parafunction initiated by occlusal interferences • Central nervous system aetiology . Rees et al. A guide to the clinical management of attrition. BRITISH DENTAL JOURNAL , 2018 Functional theory This suggests that tooth wear occurs due to prolonged contact of the teeth and the patient having a broad envelope of function. They found that the broader grinding type chewing pattern had significantly greater levels of occlusal wear compared to the ‘chopping’ type.

21. Parafunction initiated by occlusal interferences The theory states that parafunction can be initiated by occlusal interferences and therefore managed clinically by occlusal adjustments or extensive rehabilitations. Unfortunately, the evidence in the literature does not support this theory. Studies have found that occlusal interferences could not cause bruxism or stop it.

22. Central nervous system Etiology B ruxism is a neurological problem and the tooth damage is a consequence of a neurologically initiated activity manifesting as grinding and tooth surface loss. Essentially, sleep bruxism occurs following sleep-related micro-arousals that originate in the brain stem. These micro-arousals cause the heart rate to increase following which brain activity increases. This is followed by activation of the suprahyoid muscle which is followed by rhythmic masticatory muscle activity resulting in bruxism

23. In addition to the causes of attrition, there are a number of other factors which may accelerate the process of attrition Habitual chewing on hard food stuffs Habitual chewing on hard foods or unusual food stuffs such as bone chewing may exacerbate tooth surface loss. Lack of posterior support Many clinicians consider that a lack of posterior support can eventually lead to more tooth wear on the remaining anterior teeth. While other authors found no relationship between the number of missing posterior teeth and anterior tooth wear This is often controversial and therefore further studies are needed to prove this theory

24. Ecstasy Around 1.5% of the population use ecstacy (Amphetamine) and it is the second most popular recreational drug in 16–24 year olds . The main side effects of this drug are bruxism and a profound xerostomia that last for around 6–8 hours. This is a good example of a combined attrition and erosion aetiology Selective 5-hydroxytryptamine reuptake inhibitors (SSRIs) It is the commonest type of antidepressants used to manage anxiety and depression Recent reports suggest that SSRIs may cause bruxism,

25. CLINICAL MANIFESTATION The first manifestation: appearance of a small facet on cusp tip or ridge or a slight flattening of incisal edge. In severe cases: “a reverse cusp” situation might be created in place of the cusp tips and inclined planes

26. Attrition can predispose to or precipitate any of the following :- Proximal surface attrition (proximal surface faceting) Occluding surface attrition (occlusal wear) The degree of wear in both arches is normally equal. Sometimes there may be presence of peripheral, ragged, sharp enamel edges . The presence of hypertrophic masseter is a warning sign of the impact of bruxism When surface attrition is SLOWER - compensated by, intrapulpal deposition of secondary & tertiary dentin Severe attrition leads to pulp exposure

27. PROXIMAL SURFACE ATTRITION (PROXIMAL SURFACE FACETS) Results from surface tooth structure loss and flattening, widening of the proximal contact areas.

28. OCCLUDING SURFACE ATTRITION ( OCCLUSAL WEAR) It is the loss ,flattening , faceting or reverse cusping of the occluding elements. It leads to loss of vertical dimension of the tooth

29. EFFECTS OF ATTRITION Deficient masticatory capabilities Blunting of the cusps needs more force to shear food items.   Cheek biting and gingival irritation Decay Hypersensitivity TMJ problems - extreme strain on the muscles of stomatognathic system

30. TREATMENT MODALITIES In developing a treatment plan the dentist should consider the following factors: Whether the wear is localised or generalised. Degree of attrition – mild, moderate or severe Factors affecting the patient’s speech, function and orofacial aesthetics. The behavioural, psychological, anatomical, developmental and physiological limitations of the patient. Observation and palliative strategies

31. Management Of Localized Anterior Tooth Wear

32. Management Of Localized Posterior Tooth Wear

33. Management Of Generalized Tooth Wear

34. BASED ON THE DEGREE OF ATTRITION MILD ATTRITION MODERATE ATTRITION SEVERE ATTRITION Instructions for oral hygiene Fluoride application Use of desensitizing toothpaste Use of temporary restorations R estoration of the vertical dimension to improve function and esthetics. Treatment options include Endodontic therapy followed by crown placement or extraction of affected teeth and replacement with conventional dentures, overdentures and overlay prosthesis, etc.

35. Treatment depends upon the following categories: Category I: Appearance is satisfactory Category II: Appearance is unsatisfactory and there is no need to raise the vertical height Category III: Appearance is unsatisfactory but there is need to raise the vertical height, which in turn depends on the availability of space, whether it is present or needs to be created. BASED ON APPEARANCE

36. Category I (Appearance is satisfactory) Counselling is required in patients with parafunctional habits. Habit breaking appliance should be given in patients with bruxism or clenching. Conventional Restorative Treatment Exposed pits are filled Occlusal disharmony is corrected Consideration to be given to crown lengthening procedure

37. Category II (Appearance is unsatisfactory but there is no need to raise the vertical height). Teeth are restored, preferably with all ceramic crowns or laminates. The crowns can manage occlusal attrition as well as fractured cusps. Occlusal guard for protection against nocturnal clenching like bleaching trays, etc.

38. Category III (Appearance is unsatisfactory and there is a need to raise the vertical height Generalized increase in vertical height is required. Orthodontic tooth movement can be used for over-eruption of posterior teeth creating space for the anterior teeth.

39. Sequence of treatment: Management of dentinal hypersensitivity Pulpally involved teeth - based on restorability endodontic therapy or extracted Parafunctional activities , notably bruxism, should be controlled with the proper disoccluding -protecting occlusal splints. Myofunctional, TMJ , or any other symptoms in the stomato-gnathic system should be diagnosed and resolved. Occlusal equilibration should be performed after all notable symptoms are relieved Occlusal equilibration, by selective grinding of tooth surfaces. Rounding and smoothing the peripheries of the occlusal tables.

40. MANAGEMENT OF DENTIN HYPERSENSITIVITY Nerve desensitization Potassium nitrate Protein precipitation Gluteraldehyde Silver nitrate Zinc chloride Strontium chloride hexahydrate Plugging dentinal tubules Sodium fluoride and Stannous fluoride Strontium chloride Potassium oxalate Calcium phosphate Calcium carbonate Bio active glasses

41. Dentin hypersensitivity: Recent trends in management, Journal of Conservative dentistry, 2015 Dentine adhesive sealers Fluoride varnishes Oxalic acid and resin Glass ionomer cements Composites Dentin bonding agents Lasers Nd-YAG and Er-YAG laser GaAlAs ( galium -aluminium-arsenide laser) Natural medication Propolis Periodontal surgical procedures

42. Restoration therapy is needed in cases Where there is loss of vertical dimension. Or a progressive loss of tooth structure is observed compromising the tooth strength . Caries ,if present Defect which may contribute to a periodontal problem. Worn tooth contour, (usually proximal ) which is not conducive to the maintenance of periodontium . A tooth is cracked or endodontically treated RESTORATION

43. They should be accomplished very cautiously and carefully in the following sequence. Verify and re-verify its necessity, i.e., be sure that the alveolar bone did not grow occlusally at the same pace that attrition occurred. Estimate how much vertical dimension lost. Estimate how much additional vertical dimension the stomato-gnathic system can accommodate without untoward effects RVD = VD at Rest OVD = VD at Occlusion FWS = Freeway Space

44. Vertical Dimension It gives an estimate up to what should be the height of the worn clinical crowns be increased . The additional V.D. that the stomatognathic system can accommodate without untoward effects is estimated Increasing the Vertical dimension of occlusion can lead to Clenching (increased muscle activity) Muscle fatigue Soreness of teeth, muscle and joints Problems in phonetics Occlusal instability Intrusion of teeth Therefore, periodic monitoring and assessment is required for a period of time until the patient is no more uncomfortable to the new dimension of occlusion

45. I f a substantial increase in the dimension is to be considered (>2mm), it is wise to build a temporary restoration or removable occlusal splint that can be easily adjusted through subsequent addition or removal of material • Composite temporary restorations are most frequently used . • Permanent restoration should be done in a cast alloy material to preserve the remaining the tooth structure and to assure the integrity of the supporting tissues.

46. These restorations should be cemented only temporarily for an extended period of time ,until it is established that no untoward symptoms would occur. An acrylic splint ( as a stabilization splint) may be necessary to protect the dentition from further damage due to attrition and this is frequently the only treatment required to prevent further tooth tissue loss . The splint would need to be relined with cold cure acrylic resin to improve the retention of the appliance and for occlusal adjustments

47. In case of inadequate anterior clearance for restoration/ crown placement, space can be created by Occlusal adjustment Orthodontic extrusion Crown lengthening Dahls appliance Extraction or surgical repositioning Dahls Appliance The Dahl Concept refers to the relative axial tooth movement that is observed when a localised appliance or localised restorations are placed in supra-occlusion and the occlusion re-establishes full arch contacts over a period of time. This principle was known prior to the publication of Dahl‘s work in 1975 . For example, the anterior bite platforms of removable orthodontic appliances have long made use of this effect (Cousins AJ, Brown WA, Harkness EM, 1969)

48. Other phrases used for this process are ‘ minor axial tooth movement’ ‘fixed orthodontic intrusion appliances’ ‘ localised inter-occlusal space creation’, and ‘relative axial tooth movement Dahl and his coworkers (1975) were, however, the first to describe how it may be used in the management of the worn dentition . They described the use of a partial bite raising appliance ‘ to create inter-occlusal space in an 18-year-old patient with severe localised attrition. The removable appliance was cast in cobalt-chromium , placed on the palatal aspects of the upper anterior teeth, Poyser NJ et al. The Dahl Concept: past, present and future. British Dental Journal, 2005

49. The objectives of the Dahl concept are to either create sufficient inter-occlusal space for the placement of restorations or the re-establishment of occlusal contacts following the placement of restorations that have intentionally been placed in supra-occlusion. Requirements:- The m aterial should be placed on the incisal/occlusal aspect of those teeth where the creation of interocclusal space is necessary. The thickness of this material placed should directly relate to the amount of inter-occlusal space that is required. This will determine the increase in the vertical dimension of occlusion as measured at that particular site in the mouth.

50. Ideally an occlusal bite platform should be constructed to ensure that occlusal forces are directed along the long axis of the teeth. Stable inter-occlusal contacts should be provided. The appliance should not impede the movement of the disoccluded teeth The occlusion tends to re-establish after about six months on average but it can take up to a period of 18-24 months.

51. More eruption than intrusion was seen in the younger age group. In some cases the time taken for tooth movement to occur is faster than that which could be achieved with orthodontic tooth movement To ensure that the patient is able to tolerate the increase in the vertical dimension , it is necessary to wear the appliance for at least 6- 8 weeks (12 hours /day ,generally evenings and nights) At this time if the muscles of mastication are flaccid and show no tenderness to palpation and the TMJ‘s are free from pain , palpation and opening clicks , then it is usually safe to proceed , to the restorative care .

52. A one-stage Dahl procedure I nvolves the placement of definitive indirect laboratory constructed restorations in supra-occlusion, whereby no interim appliance is used to create the inter-occlusal space. Adjustment of the restorations may be required but this may lead to weakening of the restoration, possible perforation, microleakage, sensitivity, and loss of the restoration. It is for this reason that the authors advocate a Two-stage Dahl procedure using direct composite resin as the interim Dahl appliance. Composite is a useful material for the creation of inter-occlusal space in two stage Dahl procedures. Once sufficient space has occurred, its followed by placement of laboratory constructed definitive restorations.

53. Direct composite restorations placed as fixed Dahl appliances Conventional metal-ceramic restorations placed once sufficient inter-occlusal space created. Advantage of using composite:- I nexpensive, simple to use and adjust Has favourable wear characteristics. It can be easily removed for subsequent definitive extra-coronal restorations,

54. ‘ Double Dahl’ technique - where both the upper and lower anterior teeth are restored simultaneously Rees et al. A guide to the clinical management of attrition. British Dental Journal. 2018

55. Indirect Art Glass restorations 83% Gow and Hemmings 2002 (2 months)

56. Djulaeha and Sukaedi : The management of over closured anterior teeth due to attrition. Dental journal 2009 Preoperative view Patient had missing posterior teeth and severe attrition of maxillary anteriors . Because of which vertical dimension was lost or reduced. The heightening of the occlusal vertical dimension must be done gradually in order to let the muscles of the mastication adapt to the new occlusal vertical dimension. At first stage, the restoration of the anteriors were done by lengthening incisal, 2 mm, with composite restoration to improve the aesthetics and heighten the occlusal vertical dimension. Then the patient was evaluated for two weeks. The patient had no problems with her temporomandibular joint After Composite restoration

57. Tooth preparation was done for placing temporary bridge (self cure acrylic) followed by the heightening process of occlusion about 2 mm of the temporary bridge in order not only to maintain the aesthetics and to improve the vertical dimension of occlusion After evaluating the patient for 2 more weeks, the long span bridge with 12 units made of porcelain materials fused to metal materials was processed for upper jaw. An acrylic removable partial denture was given for missing lower teeth The long span bridge of upper jaw; lower acrylic removable partial denture. Temporary bridge of upper anterior teeth Postoperative view

58. Abnormal tooth surface loss resulting from direct frictional forces between the teeth and external objects or from frictional forces between contacting teeth components in the presence of abrasive medium. - Sturdevant Tooth surface loss resulting from direct frictional forces between teeth and external objects, or from frictional forces between contacting teeth components in presence of abrasive medium. - Marzouk - Shafer ABRASION Abrasion is defined as the pathological wear of tooth substance through some abnormal mechanical process.

59. Clinical features of Abrasion Males are comparatively more affected than females. Premolars and canines are more susceptible to abrasion probably because they are placed slightly protruded in the dental arch. Right-handed individuals show a preponderance of lesions on the left side and vice versa. It occurs most frequently on the cervical neck of the teeth. The labial or buccal surfaces is most affected in case of tooth brush abrasion and lingual surfaces ( in case of poorly fitted clasps and artificial dentures ) Incisal surfaces are affected in certain cases – habits/occupation

60. Morphology of abrasive lesions Abrasion lesions are of varying morphology and may be classified as : Notch/V- shaped defects : where oblique occlusal and cervical walls intersect at a certain depth with no definite axial wall in between them. C-shaped defects(C): where cross section of the defect is C-shaped with rounded floors. Under cut concave (UC): where occlusal and cervical walls intersect with a definite axial wall in between them. Divergent box (DB): where a definite axial wall is present with the occlusal and cervical walls diverging towards the surface.

61. C LINICAL SIGNS AND SYMPTOMS I t results in saucer shaped or wedge shaped indentation on the tooth surface The surface of the lesion is extremely smooth and polished and it seldom has any plaque accumulation or caries activity in it . T he surrounding walls tend to make a V shape ,by meeting at an acute angle axially. Peripheries of the lesion are angularly demarcated from the adjacent tooth surface. Probing or stimulating the lesion can elicit pain . Hypersensitivity may be intermittent in character appearing and disappearing at occasional or frequently repeated periods .

62. ETIOLOGY AND PATHOGENESIS Different foreign substances produce different patterns of tooth abrasion Though the etiology is varied, the pathogenesis under these different conditions is essentially different Various types of abrasion: TOOTHBRUSH ABRASION OCCUPATIONAL ABRASION HABITUAL ABRASION PROSTHETIC ABRASION

63. TOOTHBRUSH ABRASION It is mostly due to Improper oral hygiene practices Oral hygiene products Improper oral hygiene practices Aggressive tooth brushing Improper brushing technique i.e by using horizontal brushing method Vigorous use of toothpicks or tooth floss may result in abrasion in proximal surfaces Frequency; time and forces applied during brushing also affects the occurrence of lesion

64. Oral hygiene products : Tooth brush abrasion depends on Type of the toothbrush used – soft, medium, hard Shape of tooth bristles used Flexibility and length of the tooth brush handle affecting the grip of the tooth brush The grittiness, pH and amount of dentifrice used. Abrasiveness of dentifrice Tooth powder is generally five times more abrasive than its dentifrice counterparts Robinson stated that the most common cause of abrasion of tooth surface is the use of abrasive dentifrice.

65. The extent, depth and rate of formation of toothbrush abrasion depends on The size of the abrasive : larger and more irregular The direction of brushing strokes : Horizontal directions are the most detrimental. The percentage of abrasives : higher the percentage is, the more abrasion The type of abrasives : Silica abrasives are more abrading than phosphate and carbonate ones. The diameter of brush bristles : greater the diameter, the more the abrasion. The type of bristles : Natural bristles are more abrasive than synthetic (mylar) ones.

66. The forces used in brushing : more the force, the more abrasion there will be. (average manual brushing force = 1.6+0.3N) The type of tooth tissues being abraded. Generally, enamel is quite hard and not easily abraded therefore it serves as a protection for the underlying dentin, which is abraded 25 times faster. Cementum is the softest of all tissues and shows an abrasion rate of 35 times higher than enamel.

67. OCCUPATIONAL ABRASION Notching of incisal edge of maxillary anteriors may be seen in carpenters, shoemakers, tailors who hold nails, tacks or pins between their teeth. HABITUAL ABRASION Habitual pipe smokers may develop notching of teeth that confirms to the shape of pipe stem – Shafers

68. Habitual opening of bobby pins may also result in notching of the incisal edge of maxillary anteriors Also called Depression abrasion - where one can see an abraded depression on the occluding surfaces of teeth at a latero-anterior portion of the arch, coinciding with intra oral location of the pipe stem.

69. Oral piercings Lingual (tongue) piercings may result in abnormal tooth wear. Biting or chewing of the device can lead to severe abrasion accompanied by hypersensitivity. It involves enamel, dentin and may also lead to pulp involvement. Holding the device between the teeth over an extended period of time may also lead to widening of interdental spaces and tooth migration L.L Francu . Lingual piercing : Dental anatomical changes induced by trauma and abrasion. Romanian journal of anatomical functional, clinical, microscopy and anthropology, 2012

70. PROSTHETIC ABRASION • Dentures with porcelain teeth opposing natural teeth. Porcelain causes more abrasion to the natural teeth than other restorative materials. The proximate damage can include loss of natural tooth structure, reduced longevity of opposing restorations and even unfavourable changes to the vertical dimension of occlusion. • Extremely rough occluding surface of the restoration enhancing its abrasive capability . • ill fitting dentures and clasps ,producing a constant wear of the affected surfaces.

71. In case of tooth brush abrasion, patient should be advised or educated about the brushing technique and the tooth brush, dentifrice to be used. Instituting proper oral hygiene measures Prevent the patient from practicing causative habits. The objective should be to prevent any further destruction of the tooth. Prosthetic/ iatrogenic causes for abrasion to be avoided. In case of such abrasion, early diagnosis and proper management to be carried out such as Correcting or avoiding ill fitting metal clasps and dentures Treatment modalities for abrasion: Diagnose the cause of abrasion and take necessary steps to eliminate the etiological factor

72. Abrasive lesions at non-occluding tooth surfaces should be e valuated critically for the need for restoring them. Edges of the defect should be eradicated to a smooth, non - demarcating pattern relative to adjacent tooth surface. Tooth surface then should be treated by fluoride solution to improve caries resistance If there is involvement of cementum / enamel only If the lesions are multiple, shallow( not exceeding 0.5 mm in dentin) and wide Restoration not needed

73. If the abrasive lesion involves an anterior tooth or facially conspicuous area of a posterior tooth, at a non occluding tooth surface, restoration done with Direct tooth colored materials If the involved teeth is extremely sensitive - Desensitize the exposed dentin before restoration . Desensitization is done by • 8-10% sodium/stannous fluorides for 4-8 minutes. • Iontophoresis- --using an electrolyte containing fluorides If lesion is wedge (V) shaped and exceeds 0.5 mm into dentin Restoration needed

74. Restoring cervical abrasions In many instances no treatment is necessary but restoration is indicated when : Caries ,if present . Sensitivity is present. Lesion is esthetically objectionable . If the defect contributes to a periodontal problem The area to be involved in the design of a removable partial denture. When the depth of defect is found to be close to pulp Or a progressive loss of tooth structure is observed c ompromising the tooth strength

75. Restorative materials used are: • Glass ionomer restorative material. • Resin modified glass ionomer. • Polyacid-modified resin composites. • Resin composites. High modulus restorative materials are unable to flex in the cervical regions when the tooth structure is deformed under occlusal load and ,therefore the restorative materials can be displaced from the cavity . ( Heymann HO , Sturdevant Jr ,Baynes S ,JADA,122(2) 41- 57 ) An intermediate material with reduced elastic modulus may function as a stress absorbing layer and improve marginal sealing . (Kemp-Scholte CM , Davidsson,CL complete marginal seal of class V resin composite restorations affected by increased flexibility .JDR 1990 ;69:1240 -3 )

76. M aterials with low elastic modulus for restoring cervical abrasion such as Microfilled composites ( Heymann and others ,1991 : Levitch and others ,1994 ) Flowable resins ( Unterbink ,Liebenberg ,1999: Li and others 2006 ) Glass ionomer cements ( Loguercio and others ,2003:Burgess and others ,2004) Have been used in restoring cervical lesions ,with the aim of absorbing the stresses generated during the polymerization shrinkage of composites and mechanical loading in which the teeth are subjected during function .

77. ABFRACTION Abfraction represents the mechanical flexure theory where tooth bending and flexing during function and parafunction create flexural stress in the cervical area of the tooth resulting in microfractures of the crystalline structure of the enamel and dentin in that area. K.B. Troendle and K.M. Gureckis . Noncarious Cervical Lesions: Prevalence, Etiology , and Management. Textbook of Erosion and its clinical managemen t. Grippo in 1991 , coined the term “ abfraction” to describe the pathologic loss of both enamel and dentin caused by biomechanical loading forces. - Milosevic A. Dent Update, 1998 Loss of tooth surface at the cervical areas of the teeth caused by tensile and compressive forces during tooth flexure

78. Clinical features The lesion is typically wedge shaped with clearly defined internal and external line angles Affects buccal/labial cervical areas of teeth Deep, narrow V-shaped notch Can manifest as C-shaped lesions with rounded floors or mixed shaped lesions with flat, cervical, and semicircular occlusal walls Commonly affects single teeth with excursive interferences or eccentric occlusal loads Contributing factors can also modify the clinical appearance of these lesions by making the angles less sharp and the outline broader and more saucer-shaped.

79. Moreover, abfraction lesions may be deeper than wider depending on the stage of progression and related causal factors In early stages, the lesion appears as a minor irregular crack or fracture line on the enamel surface. In late stages, it appears as notch extending into the dentin

80. El- Marakby AM et al. Noncarious Cervical Lesions as Abfraction: Etiology , Diagnosis, and Treatment Modalities of Lesions: A Review Article. Journal of Dentistry. 2017

81. Etiology and Pathogenesis Some authors explain the formation of cervical, wedge shaped defect by the heavy force in eccentric occlusion resulting in flexuring (elastic bending) of the tooth. Grippo et al in 1991 suggested that static or cyclic forces created tooth loss at the cervical area When the tooth is loaded in long axis ,the forces are dissipated with minimal stress on enamel and dentin . If the direction of force changes laterally ,teeth are flexed towards both the sides . T he flexure may lead to breaking away of extremely thin enamel rods ,as well as microfractures of cementum and dentin .

82. Later Lee and Eakle in 1984 proposed a multifactorial etiology, with a combination of occlusal stresses, abrasion and erosion. Once micro fracture occurred, water and other small molecules penetrate the broken hydroxyapatite chemical bonds and makes the tooth susceptible for chemical erosion and toothbrush The resulting defect has a smooth surface . Also known as idiopathic erosion (Lee WC, Eakle WS, J Prosthet Dent 52(3): 374-380, 1984.)

83. Stresses that concentrate to produce abfractions in teeth usually are transmitted by occlusal loading forces. ( Whitehead SA, Wilson NHF, Watts DC. J Esthet Dent 2000) Occlusal interferences, premature contacts, habits of bruxism and clenching all may act as stressors. (Pintado MR, DeLong R, Ko C, Sakaguchi RL, Douglas WH. Correlation J Prosthet Dent 2000) Differences in support provided by the bony socket, gross morphology of the tooth, the presence or absence of restorations, and the microscopic structure of the tooth are all confounding variables that could influence the occurrence of lesion.

84. Grippo et al . ABFRACTION, ABRASION, BIOCORROSION, AND THE ENIGMA OF NCCLS. Journal of Restorative and Esthetic Dentistry. 2012 ETIOLOGICAL FACTORS

85. Theories of Abfraction Abfraction lesions: etiology , diagnosis, and treatment options. Journal of Clinical, Cosmetic and Investigational Dentistry, 2016 The theory of abfraction sustains that tooth flexure in the cervical area is caused due to occlusal compressive forces and tensile stresses, resulting in microfractures of the hydroxyapatite crystals of the enamel and dentin with further fatigue and deformation of the tooth structure. The theory suggests that the lesion would continue to enlarge as the bending and flexing is repeated finally resulting in chipping away of the hard tissue

86. . S ome researchers even proposed that the occlusal forces on the tooth from chewing and swallowing leading to concentration of stress and flexion in the area where the enamel and cementum meet, as the etiological factor of Abfraction Others have suggested that abrasive agents like tooth brushes, abrasive paste and or erosion also contribute to abfractive lesions Recent studies have suggested that there is weak relation between the occlusal factors and the occurrence of cervical lesions. El- Marakby AM et al. Noncarious Cervical Lesions as Abfraction: Etiology , Diagnosis, and Treatment Modalities of Lesions: A Review Article. Journal of Dentistry. 2017

87. Abfraction lesions are also said to be facilitated by the thin structure of the enamel and the low packing density of the Hunter–Schreger band (HSB) at the cervical area. Lynch CD et al. Hunter-Schreger band patterns in human tooth enamel. J Anat. 2010 D entin demineralization promotes the formation of NCCLs from an early stage, whereas occlusal stress is an etiological factor that contributes to the progression of these lesions Wada I et al. Clinical assessment of non carious cervical lesions using swept source optical coherence tomography. J Biophotonics . 2015

88. Diagnosis of Abfractive lesions Proper diagnosis can be achieved by complete patient anamnesis accompanied by a careful clinical examination If a tooth has an abfraction, the occlusal loading on the tooth can be tested in centric occlusion and in excursive movements with occlusal marking paper. The tooth with abfraction will show a heavy marking on one of the inclines of the tooth Mainly seen in malaligned tooth Abfraction lesions: etiology , diagnosis, and treatment options. Journal of Clinical, Cosmetic and Investigational Dentistry, 2016

89. Assessment of activity of abfractive lesions Approaches to determine lesion activity include the use of standardized intra-oral photographs, study models, and measurement of lesion dimensions over time. Activity assessment can also be performed by using a scratch test. Scratch test - Its a novel method for determining the activity of abfraction lesions over time ( Kaidonis JA. The tooth wear :view of anthropologists ,Clin Oral Investig 2008) A no.12 scalpel blade is used to superficially scratch the tooth surface . Visual observation gives an indication of rate of tooth structure loss Loss of scratch definition or loss of the scratch altogether signifies active tooth structure loss.

90. Furthermore, several indices of tooth wear have been proposed for recording and monitoring the progression of abfraction lesions such a s Smith and Knight index. Another index has been recently proposed that includes not only lesion depth but also the width and angle between the lesion and the occlusal and cervical walls, with a scale ( DAW index by Loomba et al)   With the recent introduction of digital dentistry, future studies should also test if CADCAM systems may be useful for diagnosis and monitoring of NCCL activity

91. DAW (DEPTH, ANGLE and WIDTH) Classification Loomba K et al. proposal for clinical classification of multifactorial noncarious cervical lesions. Gen Dent 2014

92. Management of Abfraction Monitoring the lesions when abfraction lesions are painless and do not affect esthetics, i.e are shallow in depth (,1 mm or less), it is advisable to monitor the progression of these lesions at regular intervals without any treatment intervention. The assessment of lesion activity can be performed every 6 months to 12 months and during regular hygiene visits. If the tooth wear is likely to compromise the long-term prognosis of the tooth, operative intervention may be required Abfraction lesions: etiology , diagnosis, and treatment options. Journal of Clinical, Cosmetic and Investigational Dentistry, 2016

93. Occlusal adjustments and Occlusal Splints Occlusal adjustment has been proposed as an alternative treatment to prevent the initiation and progression of these lesions and to minimize failure of cervical restorations. Occlusal adjustment may involve A ltering cuspal inclines Reducing heavy contacts, and Removing premature contacts Occlusal splints to reduce the amount of nocturnal bruxism and nonaxial tooth forces have also been recommended to prevent the initiation and progression of abfraction lesions.

94. Issue of hypersensitivity The chronic nature of abfraction, which is accompanied by the natural process of dentinal remineralization, will slowly relieve tooth sensitivity. If sensitivity persists, the exposed dentin may require therapeutic treatment to relieve or eliminate discomfort. Various cost-effective and non-invasive treatments like application of desensitizers on to the exposed dentinal tubules or use of desensitizing toothpastes, which might partially or completely occlude the open dentinal tubules Different types of lasers have also been introduced as an alternative option for treating tooth sensitivity Other non-invasive treatments include temporary sealants such as Varnishes and Dentin bonding agents. In extreme cases of Hypersensitivity unresponsive to non-invasive procedures, a restoration might be required .

95. Restorative treatment Restorative treatment of abfraction lesions should be considered only when one or more of the following conditions are present: A ctive, cavitated carious lesions associated with abfraction lesions C ervical margins or all lesion margins are located subgingivally and preclude plaque control, hence increasing the risk for caries and periodontal disease, E xtensive tooth structure loss, which compromises the integrity of the tooth, or the defect is in close proximity to the pulp, or the pulp has been exposed, P ersistent dentinal hypersensitivity, in which noninvasive therapeutic options have failed, P rosthetic abutment, and E sthetic demands.

96. Authors have suggested that during the selection of restorative materials for cervical lesions, materials with a low modulus of elasticity, good adhesion to dentin, resistance to wear, and ability to endure acid dissolution should be considered. Of the available restorative techniques, adhesive systems, specifically Resin Based Composites, are the preferred choice of dentists to restore NCCLs, likely due to their esthetic and more conservative components. Although the use of GICs, RMGICs, and the lamination technique of GIC⁄RMGIC with RBC has been advocated for NCCL restorations

97. Tyas recommended that RMGIC should be the first preference In esthetically demanding cases, RMGIC/GIC liner laminated with resin composite. ( Tyas MJ. The class V lesion – aetiology , restoration,Aust . Dental Journal.1995) Vandelwalle and Vigil r ecommended the use of M icrofilled resin composite (low modulus of elasticity ) as it will flex with tooth and not compromise retention (KS Vandelwalle . Guidelines for the restoration of class V lesions. Gen Dent 1997)

98. Root coverage surgical procedures In most cases of lesions associated with gingival recession, there is a loss of the hard tissues of the tooth crown causing the CEJ to disappear, and root coverage procedures are not effective at treating these crown defects. Consequently, a combined restorative-surgical approach may be indicated in these clinical situations. In this approach, the restoration must be placed prior to the surgical procedure for better visibility of the operative field and to provide a stable, hard, and convex substrate for the Coronally Advanced Flap (CAF) Recent studies have pointed out that the combination of Coronally Advanced Flap with connective tissue graft (CTG) provides the best clinical outcomes for root coverage when appropriately performed.

99. Resin composite plus connective tissue graft to treat single maxillary gingival recession associated with non-carious cervical lesion: Randomized clinical trial. J Clin Periodontol 2016 AIM : to evaluate clinically, the esthetics and the patient centered parameters after the treatment of gingival recession associated with non-carious cervical lesions by connective tissue graft (CTG)alone or combined with nanofilled resin composite restoration METHODOLOGY In the CTG Group , In the combined group (COMPOSITE + CTG)

100. Pre-operative view After flap elevation and rubber dam isolation Nanofilled resin composite placed CTG placed and flap was coronally advanced & sutured 1 year follow-up. RESULTS Both groups can successfully treat gingival recession associated with cervical lesions. Reduction of dentinal sensitivity was more in the combined approach (CTG + Composite)- sensitivity reduced from 88.8% of sites to 5.5% of sites whereas reduction was 94.45 to 44.4% in CTG group. Also, the groups that received restoration presented better marginal contour while the other group often showed flattened margins

101. DISCUSSION Most of the cervical lesions did not achieve complete coverage with gingival tissues. Thus part of the cervical lesion was still exposed to the oral environment in the CTG group. While in the combined group, the defect is completely restored, sealing the dentinal tubules and thereby effective in reducing symptoms The teeth with cervical lesions often presents a flattened marginal contour . This may be the reason for flattened gingival margins in the CTG group following the healing period. Restorations may help to achieve a better anatomical outcome, helping to modulate the marginal contour and give a good final esthetic result

102. Loss of surface tooth structure by chemical action in the continued presence of demineralizing agents(acids). - Sturdevant Erosion can be defined as the loss of tooth structure resulting from chemico - mechanical acts in the absence of specific microorganisms. - Marzouk Loss of tooth substance by chemical process that does not involve known bacterial action. - Shafer EROSION

103. Affect of erosion in enamel Acid diffusing into the narrow pores between the crystals results in partial loss of mineral, increased porosity and reduction of mechanical strength of the outer layer of enamel, which is hence referred to as the ‘softened layer’. Textbook of Erosion and its Clinical Management, Bennett T

104. Affect of erosion in dentin Erosion of dentin leaves behind a persistent layer of demineralised collagenous matrix. D emineralization of dentin is firstly apparent at the interface between inter- and peritubular dentin. With increasing exposure time, the erosive attack results in a hollowing and funneling of the tubules. Finally, the peritubular dentin is completely dissolved. Erosive demineralization results in exposure of an outer layer of fully demineralized organic matrix followed by a partly demineralized zone until the sound inner dentin is reached Insights into preventive measures for dental erosion. Journal of applied oral science. 2009

105. Textbook of Erosion and its Clinical Management, Bennett T Factors controlling erosive demineralization Chemical factors Enamel - Degree of saturation with respect to hydroxyapatite Degree of saturation with respect to fluorapatite pH Buffer capacity Fluoride concentration Phosphate concentration b) Dentin – Buffer capacity Carbonate concentration 2. Physical factors – Temperature Fluid movement

106. Dissolution also tends to be reduced or even abolished in undersaturated solutions in which the calcium concentration is much higher than the phosphate concentration. Calcium addition to acidic solutions can reduce erosive potential. The factors that have been most consistently identified as significant factors in erosive potential are pH and buffer capacity The higher the buffer capacity , the pH of the solution within the pores will rise and the lesser the overall rate of erosion. pH - Laboratory experiments show that erosion of enamel is very rapid at pH of about 2.5 but slows down as the pH increases

107. Fluorapatite is less soluble than hydroxyapatite, indicating that replacement of all the OH− ions in hydroxyapatite by F− ions causes a large decrease in solubility. Temperature - Temperature affects the rate of most chemical reactions and erosion is no exception. Studies show that both early erosion (measured by softening) and later erosion (loss of surface) increase over the range 4–75 °C Fluid Movement – In active fluid movement – the static interfacial layer of liquid becomes thinner and there is an improved supply of H+ ions and removal of mineral-ion end products. Increased movement of fluid thus speeds up dissolution. Erosion of enamel increases very rapidly at low flow rates and then increases more slowly, whereas dentin erosion increases gradually with flow rate

108. CLASSIFICATION OF DENTAL EROSION Based on Etiology Extrinsic Erosion Intrinsic Erosion Idiopathic Erosion Idiopathic erosion is the result of acids of unknown origin, i.e. an erosion-like pathology where neither tests nor anamnesis are capable of providing an etiologic explanation. Imfeld T : Dental erosion. Definition, classification and links. Eur J Oral Sci 1996:

109. Based on Pathogen etic activity – Mannerberg , J Odout Revv 1961 Manifest erosion : A n actively progressing erosion, is clinically diagnosed by its enamel border zones. These are thin where they meet the exposed dentin. In the scanning electron microscope (SEM), they show a honeycomb enamel prism pattern, resembling that seen in acid etched enamel . latent erosion: It is an inactive stage and here the prisms are much less obvious. T hrough a change in the etiologic factor, are no longer subject to further decalcification, H ave prominent thick enamel borders and do not show a honeycomb enamel prism

110. Based on Clinical severity – ECCLES in 1979 EccLES JD. Dental erosion of nonindustrial origin. A clinical survey and classification. J Prosthet Dent 1979 Class I: Superficial lesion, involving enamel only; Class II: Localized lesion, <l/3 of surface involving dentin; Class III: Generalized lesion, >l/3 of surface involving dentin. Based on these three classes, Lussi and co-workers in 1991 have published a similar, more detailed index of erosion for epidemiologic use Lussi A. Schaffner M. Hotz P. Suter P. Dental Erosion in a population of swiss adults. Community Denatl Oral Epidemiology, 1991

111. Grading of severity for facial surfaces - Lussi and co-workers in 1991 Grade : No erosion. Surface with a smooth, silky-glazed appearance and absence of developmental ridges possible. Grade I: L oss of surface enamel. Intact enamel found cervical lo the erosion and concavity on enamel whose width clearly exceeds its depth, thus distinguishing them from toothbrush abrasion. Dentin is not involved. Grade 2: Involvement of dentin for less than one half of the attacked area of tooth surface Grade 3 : Involvement of dentin for more than one half of the attackcd area of tooth surface

112. For other surfaces Grade 0: No erosion. Surface with a smooth, silky-glazed appearance and absence of developmenlal ridges possible. Grade I : Slight erosion, rounded cusps, edges of restorations rising above the level of adjacent t ooth surface, grooves on occlusal aspects, loss of surface enamel. Dentin is not involved. Grade 2: Severe erosion, more pronounced signs t han in grade I. Dentin is involved.

113. ETIOLOGY Erosion can be due to Intrinsic or Extrinsic factors Intrinsic factors Recurrent vomiting disorders b) Gastroesophageal reflux diseases Eating disorders Medical conditions Psychogenic vomiting syndrome Chronic alcoholism Side effect of drugs Pregnancy induced vomiting Cyclic vomiting syndrome

114. Extrinsic factors Dehydrated items Acidic foods c) Medications W ines Alcoholic Beverages Soda and Soft Drinks S ports Drink Fruit Juices Tobacco Citrus Fruits A nalgesics Vitamins Antisialogogues Drug abuse Asthamatic medications

115. d) Oral Health care Low pH toothpaste and mouthrinse Abrasive toothpaste Toothbrushing technique e) Occupation Industrial workers Swimmers Professional wine tasters f) Other factors include :- Bleaching Chewing gums Lifestyle or behavioural factors

116. Eating Disorders An eating disorder can be defined as an unusual eating behavior with insufficient or excessive food intake, which is associated with distress about weight or body shape Among the eating disorders, bulimia nervosa is the condition most closely related to dental erosion . Another eating disorder - anorexia nervosa . L abial surfaces of the incisors, which is the first surface that the acid gets in contact during ingestion. Another report observed severe lingual and moderate buccal erosion in almost all anorexic patients with recurrent vomiting A Rosten and T Newton. The impact of bulimia nervosa on oral health: a review of literature. British Dental Journal. 2017

117. Other features include parotid enlargement, decreased salivary secretions and xerostomia. Also, bulimic patients had lower stimulated salivary flow rates and lower bicarbonate concentrations Medical Conditions The main medical conditions associated with vomiting include G astrointestinal disorders (peptic ulcer, c/c gastritis, and gastric motility problems) M etabolic and endocrine disorders (diabetes mellitus, chronic renal failure and hyperthyroidism), Dry mouth conditions (diseases of the salivary gland, sjogrens syndrome, head and neck radiation, etc ) and N eurological and central nervous system disorders (migraine headaches and intracranial neoplasms)

118. Cyclic Vomiting Syndrome Cyclic vomiting syndrome is characterized by recurrent attacks of nausea and vomiting that may last for periods of a few days to several months, which is separated by symptom-free periods Among the common triggering factors are stress, emotional excitement, and infections Side Effect of Drugs O piate analgesics and chemotherapeutics agents. Other drugs can induce vomiting secondary to gastric irritation, such as aspirin, diuretics, and alcohol

119. Psychogenic Vomiting Syndrome Psychogenic vomiting syndrome affects mostly young women, and it involves recurrent vomiting, which may be caused by an underlying emotional disturbance. Chronic alcoholism Alcoholism can result in a series of dental implications, such as high caries incidence due to neglected oral hygiene, dental attrition due to alcohol-stimulated bruxism, and oral cancer Dental erosion due to alcohol abuse can be caused by both intrinsic factors (vomiting and regurgitation) and extrinsic factors, depending on the erosive potential of the alcoholic drink that is ingested.

120. For example, wines and alcohols have a low pH and may be highly erosive to the teeth. Erosive lesions were most commonly found at the palatal surfaces of the anterior teeth Pregnancy-Induced Vomiting Not a major risk factor for dental erosion. Certain studies have shown association with palatal erosion who had severe and prolonged vomiting during pregnancies

121. Gastroesophageal reflux diseases (GERDs) GERD has been defined as “a condition that develops a reflux of gastric contents into the esophagus or beyond: larynx, oral cavity or lung The potential for tooth erosion is variable and depends on the Composition and pH of the refluxate; Frequency and the form it reaches the mouth (either through regurgitation or belching acidic vapors) Fl ow rate Buffer capacity, Clearance action of saliva; and B rushing after the regurgitation episodes.

122. Erosive wear in GERD patients appears to be found more frequently on palatal surfaces of the maxillary anterior teeth and on the molar teeth . It was suggested that during reflux the gastric juice passes over the dorsum of the posterior third of the tongue, reaching the palatal surfaces of the upper molar teeth, and then passes over the buccal surfaces of the lower molars. The lingual surfaces of the lower molars remain protected by the ventral surface of the tongue. The acid also passes over the dorsum of the tongue, reaching the palatal surfaces of the maxillary anterior teeth

123. Acidic foods Acidic foods like vinegar, citric fruits, acidic berries, and other fruits (apple, pears, and plums) Acidic candies - contain organic acids such as citric acid and malic acid to develop the characteristic sour flavor. Sucking on sour candies can reduce the salivary pH levels below to the critical value for dental demineralization, therefore posing a risk for erosion of dental surfaces size of the candy is an important aspect, since it will determine the total length of exposure to the erosive challenge. As they dissolve slowly, they can be kept in the mouth for extended periods of time. This allows for prolonged and continuous exposure of the teeth to acids.

124. Several factors may actually vary the erosive response in individuals consuming acidic fluids. - manner in which the fluids consumed - tooth surfaces that come in contact with the fluid - duration of contact with the teeth - pH, buffering effect and content of calcium and phosphate in the drink. - swallowing habits - access to saliva - soft tissue movements. - roughness of individual food consumed. - prolonged contact of an acid with tooth surface increases its damaging potential.

125. It has been reported that any food substance with a critical pH value of less than 5.5 can become a corrodent and demineralize the teeth. ( Stephan RM, JADA 1940) ,( Gray JA, J Dent Res 1962) , (Zero DT. Cariology. Dent Clin North Am 1999) Holding ,swilling or retaining acidic drinks and foods in the mouth prolongs the acid exposure on the teeth increasing the risk of erosion . ( Mossazzez R ,Smith BGN,Barlett DW,Oral Ph and drinking habit during the ingestion of carbonated drink in a group of adolescents with dental erosion ,J Dent 2000)

126. Medications Aspirin, ascorbic acid (vitamin C), iron tonics, cocaine, have been implicated in dental erosion Asthamatic medications (cortisol inhaler) present erosive potential due to their acidic nature. In addition, they can decrease the salivary buffering capacity and flow rate Low pH oral care products Three acidic mouthrinses: acidified sodium chlorite mouthrinse (pH 3.02), essential oil mouthrinse (Listerine®, pH 3.59), and a hexetidine mouthrinse (0.1 %, pH 3.75), were shown to cause progressive enamel surface loss over time, similar to that of an orange juice and higher than that of mineral water.

127. Non – fluoridated toothpaste contributed more to dental erosion than fluoride containing toothpastes. This finding was attributed to both the presence of citric acid/citrate and absence of fluoride in the toothpaste. Abrasive Toothpaste Highly abrasive toothpastes may facilitate the disruption of the acquired dental pellicle as well as abrade away dental surfaces previously softened by an erosive challenge. This is even more relevant in the presence of exposed root dentin surfaces. Dentin is more susceptible to abrasive and erosive insults and less responsive to remineralization. whitening toothpastes causes more erosion than regular toothpastes

128. Toothbrushing Prolonged and frequent toothbrushing has been shown to increase the probability of erosive wear Brushing performed right after the erosive attack by acidic beverages, not allowing the eroded surfaces to remineralize and regain its physical strength, also contribute to erosion

129. Dental Bleaching It has been shown that some hydrogen peroxide-based gels may influence enamel surface morphology and softening suggesting erosive potential. This is substantiated by the high content of hydrogen peroxide and a low pH value of some bleaching agents Saliva Substitutes Some of these products such as Biotene ® with a pH of 4.15 and Glandosane ® with a pH of 4.08 are considered potentially erosive

130. Occupational factors Industrial workers Any industrial processing procedures that expose workers to acidic fumes or aerosols have the potential to cause dental erosion. The incisal edges of anterior teeth are primarily affected, although an increased rate of tooth wear of posterior teeth has also been reported. Sulfuric, nitric, acetic, and hydrochloric acids have all been implicated Occupations involved with galvanizing, electroplating, metal and glass etching, printing, and mouth pipetting of laboratory acids as well battery, fertilizer, and chemical manufacturing are all at risk of dental erosion unless appropriate safeguards are taken.

131. Occupational wine tasters The pH of wine was reported to range from 2.8 to 3. Professional wine taster tasting an average of 30 wines a day over 23 years showed extensive palatal erosion Competitive Swimmers Several case reports have associated competitive swimmers using improperly pH- regulated swimming pools with dental erosion Gas chlorinated swimming pools require daily pH monitoring and adjustment to maintain pool water in the recommended pH range of 7.2 to 8.0

132. Lifestyle factors Healthier lifestyle that includes a diet high in acidic fruits and vegetables may subject teeth to an increased risk of erosion. Frequent dieting with high consumption of citrus fruits and fruit juices as part of a weight-reducing plan may also be a risk factor. lactovegetarians showed signs of dental erosion and they were mostly associated to the consumption of vinegar and vinegar conserves, citrus fruits, and acidic berries. Strenuous sporting activities and exercise may lead to higher risk of erosion if frequent intake of acidic sport drinks , fruit juices, and other acidic beverages are used for fluid and energy replacement.

133. Chewing Gum Frequent use of some of the acidic chewing gums may present potential for dental erosion development, especially on the occlusal surfaces of posterior teeth For instance, replacement of gum every 4 min was able to cause significant erosive tooth wear on dentin, as it keeps the low pH values at tooth surfaces for longer time, increasing the risk for dental erosion

134. CLINICAL MANIFESTATIONS OF EROSIVE WEAR Erosive wear can be observed on the buccal/labial and lingual/palatal surfaces, which are not affected by wear in a purely abrasive environment. These surfaces typically appear glossy or silky because of the loss of small-scale surface features such as perikymata. When abrasion has occurred on erosion-softened surfaces, the occlusal wear surfaces tend to have rounded borders and a smooth transition to the adjacent tooth surface Active erosive wear may be associated with dental hypersensitivity, when the dentinal tubules remain patent

135. The same vulnerability to friction underlies the ‘cupping’ due to loss of dentin from cuspal areas and the loss of tissue from the occlusal surfaces which causes restorations to stand proud of the surface. Extensive loss of buccal and occlusal tooth structure w ith r aised amalgam restorations Multiple cupped out depressions corresponding to the cusp tip

136. Clinical signs and symptoms of Erosive wear of Intrinsic origin Wear of the palatal surfaces of the upper incisors is a very common characteristic of intrinsic erosion, whether it is caused by frequent vomiting or by regurgitation. With lesion progression the lingual surfaces of the premolars and molars become affected, and in more advanced stages, the process extends to the occlusal surfaces of the molars and to the facial surfaces of all teeth Incisal edges of the maxillary central incisors had their height reduced through a combination of erosion and attrition Palatal surfaces of maxillary dentition in which the exposed dentin exhibits a concave surface and a peripheral white line of enamel Extensive loss of enamel and dentin on the Buccal surface of maxillary bicuspids

137. On the occlusal surfaces, rounding of marginal ridges and cups was observed in addition to cupping characterized by localized exposure of the dentin Occlusal view of maxillary dentition exhibiting concave dentin depressions surrounded by elevated rims of enamel On the buccal aspect of the maxillary and mandibular teeth, these lesions were characterized by a silk-like appearance of the enamel surface with shortened appearance of the maxillary front teeth.

138. On the palatal aspect of the maxillary teeth, erosive lesions with complete loss of the enamel were readily identified by the presence of a thin band of enamel at the gingival margin and exposure of dentin on both anterior and posterior teeth In severe cases, almost complete loss of enamel, along with exposure of dentin

139. Perimylosis Decalcification of the teeth caused by exposure to gastric acid in patients with chronic vomiting Mostly seen a t the palatal and occlusal surfaces in upper arch, bucca l and occlusal surfaces of lower premolars and molars Loss of lingual enamel and dentin due to acid regurgitation aggravated by circular movements of tongue. Associated with stress reflux syndrome

140. Monitoring Tooth Erosion Recognizing how the appearance of teeth change with tooth wear ,can be helpful in assessing the activity. Most effective way to monitor wear is : C omparing the dated study casts to the clinical conditions of teeth over time It can also be used as a part of preventive regime . Restoration-resistant to acid, but the tooth is gradually dissolved

141. TOOTH WEAR INDICES FOR EROSIVE LESIONS The objective of tooth wear indices is to classify and record the severity of tooth wear or dental erosion in prevalence and incidence studies . Eccles Index in 1978 originally classified lesions broadly as E arly, S mall and A dvanced Later, the index was refined and expanded, with greater emphasis on the descriptive criteria. It breaks down into three classes of erosion, denoting the type of lesion, assigned to four surfaces, representing the surface where erosion was detected ( Eccles index for dental erosion of non-industrial origin in 1979) Bardsley et al. The evolution of tooth wear indices. Journal of clinical oral investigation. 2008

142. BEWE (BASIC EROSIVE WEAR EXAMINATION) – Bartlett et al in 2008 The BEWE is a partial scoring system recording the most severely affected surface in a sextant and the cumulative score guides the management of the condition for the practitioner S imple, R eproducible Transferable scoring system Bartlett et al. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Invest (2008)

143. TREATMENT MODALITIES Proper diagnosis of the cause of erosion is the first step A complete analysis of diet, occlusion, habits, vomiting, and environmental factors should be taken into consideration. The cause should be identified and be should eliminated. There should not be any rush to attempt restorative modalities, except in extremely symptomatic or disfiguring lesions. Tooth colored materials such as GIC or composite, capable of chemico-phyiscal bonding to tooth structure can be used with minimum or no tooth preparation.

144. PREVENTION AND CONTROL OF DENTAL EROSION Textbook of Erosion and its Clinical Management, Bennett T

145. Role of saliva : Saliva plays an important role in modifying the erosive effects of dietary foods and beverages by the following mechanisms. Dilution and clearance of an erosive agent from the oral cavity Neutralization and buffering of dietary acids by the salivary bicarbonate, phosphate and proteins Formation of a pellicle layer on the surface of enamel which protects it from demineralization by dietary acids. A. Warreth et al. T ooth surface loss: a review of literature. Saudi Dental Journal. 2020 R educe the demineralization rate by providing calcium, phosphate and fluoride ions to restore eroded enamel and dentine Both quantity and quality of saliva are known to control the extent of dental erosion.

146.   Dietary Recommendations to Prevent Erosion Reduce the intake of highly acidic foods and drinks, and if possible limit their intake to mealtimes Such foods and drinks as: • Carbonated soft drinks to include diet and sports drinks • Fresh citrus fruit juices and fruit juice drinks • Wine, cider, and spirits consumed with mixers • Some herbal teas (citrus and berry types) • Fresh citrus fruits (if consumed in large quantities) • Vinegar, sauces, ketchup, pickles, and chilies • Acidic sweets such as fruit drops • Chewable vitamin C tablets • Acidic candy that is hard or sticky, instead use sugar-free gum Powdered drinks with a tangy, fizzy, or acidic flavor Preventive Strategies Based On Lifestyle And Behavioral Modification

147. 2 . Reduce erosive impact of food and drinks by observing the following • Drink acidic drinks quickly and use a straw in order to reduce the contact of the drink with your teeth. • Do not swish drink around or hold them in your mouth for long periods. • After consuming food or drink that is high in acid content, rinse with water to dilute the acid, and wait an hour before brushing your teeth. • Or finish the meal with something to neutralize acid, like cheese or milk. • As salivary flow is almost nil at night, avoid acidic food and drink especially before going to bed. • Chew sugar-free gum to produce more saliva so your teeth can remineralize . • Brush with a soft toothbrush and be sure your toothpaste contains a high amount of fluoride

148. Change in Frequency and Method of Beverage Intake Clearly, a reduction in acid exposure would be the best preventive strategy to be applied in high-risk patients. The consumption of potentially erosive foods and beverages, should be limited to main meals only The straw, when appropriately used, might be a viable alternative to reduce the contact of the acid with the teeth The temperature of an acidic drink also influences its erosive potential. Taking the drink ice-cold reduces its erosive effect

149. Change in Oral Hygiene Method and Materials The time of toothbrushing after an erosive attack as well as the applied force and type of dentifrice used should be controlled. Thus, an important recommendation is to avoid brushing the teeth immediately after episode of acidic challenge such as vomiting or reflux or intake of acidic beverage. Rather patients should be advised to rinse their mouth with water or, more effectively, to use antacid products or fluoridated mouthrinse immediately after acidic challenge. Regular toothpastes are most recommended rather than whitening, It may be recommended for patients at high risk for erosion soft-bristle toothbrushes, especially if exposed dentin surfaces are present.

150. Use of Personal Protective Equipment Personal protective equipment (e.g. respiratory masks for industrial workers or ‘bite-guards’ for professional swimmers) and adherence to threshold limit values recommended by occupational health legislations are considered an important preventive strategy to decrease occupational exposure to erosive acids It is pertinent to mention that the bite guards suggested for professional swimmers should have the inside (tooth surface) coated with a small amount of sodium bicarbonate powder or milk of magnesia to neutralize any acidic water pooling in it. The guard should have occlusal coverage only, so that saliva flow to aid remineralization is maintained.

151. Control of Exposure to Intrinsic Acids Management of erosive tooth wear in patients suffering from GERD or eating disorder requires a multidisciplinary intervention, including general medicine and psychological treatment, in order to decrease the exposure to intrinsic acids The mainstay medical therapy for GERD includes Antacids, Histamine-2 Receptor Blockers (H 2 RB Or H 2 Blockers), And Proton Pump Inhibitors (PPI). Over-the-counter antacids provide symptom relief by neutralizing refluxed gastric acid thereby increasing esophageal pH.      

152. Histamine-2 receptor antagonists or blockers inhibit the secretion of gastric acid competitively by blocking the H 2 receptors located on the gastric parietal cells. Proton pump inhibitors (PPIs) are effective in controlling GERD symptoms that are refractory to antacids and H2 blockers

153. Use of Modified Products The modification of beverages or foods is another preventive strategy to reduce the risk of dental erosion. Reduction of the erosive potential of acidic beverages can be achieved by adding ions (calcium, phosphate and/or fluoride) that make the beverage more saturated in respect to tooth mineral, hydroxyapatite (HA) or by adding polymers (pectin, alginate and gum arabic polymers), which adsorb to the tooth surface to create physical barrier against acid erosion The addition of calcium or polymer has been shown to reduce the erosive potential of acidic drinks.

154. Neutralizing Intraoral Acidity In attempt to raise intra-oral pH, different products have been tested, including antacid tablets, lozenges, mineral water, milk and tap water, all used for 2 min immediately after the erosive challenge. The use of different antacid suspensions and a bicarbonate solution after erosive challenge with hydrochloric acid also significantly reduced enamel surface loss. Thus, it is advisable to instruct the patients to rinse their mouth with water or, more effectively, to use antacid products immediately after vomiting or reflux episodes Preventive Strategies Based On The Self-applied Preventive Agents

155. Use of Fluoride Concentration Dentifrices Improved enamel protection was observed with dentifrices containing titanium tetrafluoride (TiF4) and stannous fluoride (SnF2 ) when compared to NaF . The improved protection by SnF2 and TiF4 was attributed to the stannous’ and titanium’s ability to interact with the tooth surfaces forming an acid-resistant film of insoluble compounds, thus increasing the tooth tissue resistance. These compounds also demonstrated precipitation of CaF 2- like deposits ( CaF 2 -globules) that behave as a physical barrier inhibiting the contact of the acid with enamel as well as acts as a fluoride .

156. Use of Paste/Cream Containing Recaldent (CPP-ACP) Technology These are commercially available as Tooth Mousse (Asia/Australia) and MI paste (USA) and the fluoride-containing CPP-ACFP (with 900 ppm fluoride) as Tooth Mousse-plus and MI paste-plus. In Recaldent , the calcium and phosphate ions in a soluble amorphous calcium phosphate is stabilized by the protein CPP into nanocomplexes, t hese nanocomplexes bind onto the tooth surfaces and dental pellicle to create a state of supersaturation of calcium and phosphate ions in the oral cavity. When the oral pH drops during an acidic challenge, the calcium is released from the CPP to facilitate remineralization and inhibit demineralization    

157. Use of Toothpaste Containing Functionalized Tricalcium Phosphate Technology In this technology, by milling tricalcium phosphate (TCP) with organic materials (functionalization), the CaO in TCP become ‘protected’ by the organic materials, thus allowing the calcium and phosphate ions of the TCP to co-exist with fluoride ions in an aqueous dentifrice base (toothpaste) without premature TCP-fluoride interactions. Once applied in the presence of saliva, calcium compound is activated by saliva that degrades the protective coating, releasing calcium at the tooth surface, resulting in high fluoride and calcium bioavailability on the lesion surface and subsequent diffusion into the lesion to promote remineralization. Commercially available- Clinpro ™ 5000 paste

158. Use of Toothpaste Containing Novamin Technology It is a bio-active glass (calcium sodium phosphosilicate ) that binds to the tooth surfaces, and when in contact with body fluid, such as saliva, releases calcium and phosphate ions, enabling the remineralization of tooth tissue, typically forming hydroxycarbonate apatite The existing Bioactive glass (Novamin™) used in commercial toothpastes such as Sensodyne Repair & Protect and Sensodyne Complete Protection

159. Use of Polymer-Containing Toothpastes Recently, some dentifrices containing polymers have been investigated due to their potential to form a protective layer on the tooth surface, strengthening the pellicle. As active ingredients in toothpaste, organic polymers such as casein, ovalbumin, pectin, alginate and arabic gum, and inorganic polymers such as pyrophosphate, tripolyphosphate and polyphosphate have been studied   Use of Chitosan-Containing Toothpastes Incorporation of chitosan into dentifrices containing fluoride and tin or Sn significantly increased the anti-erosive/anti-abrasive effect of the dentifrice for both enamel and dentin.

160. Use of Mouth rinse Containing Protease Inhibitors Mouthrinses containing protease inhibitors, such as chlorhexidine and green tea extract, or even rinses with green tea have been shown to reduce dentin loss (around 30–40 %). Thus mouthrinses containing SnCl 2 / NaF / AmF , TiF 4 / NaF , or protease inhibitors might have potential to benefit patients that are frequently exposed to erosive challenges.

161. Remineralization methods for softened tooth surface Fluorides gels and forms varnishes calcium containing agents Recaldent (CPP_ACP) Tricalcium phosphate technology   2. Tooth surface protection Surface Protective Coatings with Remineralizing Potential GIC Resin modified GIC (RMGIC’s)   Surface Protective Coatings without Remineralizing Potential Nano filled light cured adhesive Highly filled resin   Surface Protection Using ‘Bite-Guards’ Preventive Strategies Based On Professionally Applied Agents

162. Dentin Desensitization Restoration of non- cervical lesions Non - esthetic materials (not widely used) Amalgam Gold foil Gold inlay   Minimal preparation Adhesive restoration Resin composite (with dentin bonding system) Resin composite (with glass-ionomer liner—sandwich technique) Flowable resin composite Glass ionomer RMGI Compomer 3. Ceramic veneer or full crowns 4. Conventional fixed restorations 5. Removable onlay / overlay prosthesis 6. Periodontal therapy MANAGEMENT OF DENTAL EROSION

163. Restorative materials for non-carious cervical lesions: A review. International Journal of Clinical Dental Science, 2018 RESTORATION OF NON-CARIOUS CERVICAL LESIONS Restorations at the cervical region of teeth are frequently subjected to occlusal loads and flexural stress. An ideal restorative material should present biomechanical features capable of resisting dislodgement under tension and exhibit good adhesion, retention, and marginal seal in the long run. Significantly, the selection of the ideal restorative material is hence influenced by factors such as micromechanical retention, preservation of tooth structure, esthetics, and functional harmony

164. GLASS IONONMER CEMENTS Superior retention due to chemical bonding Secondary caries inhibition due to fluoride releasing ability High abrasion resistance on final maturation In scenarios where preserving tooth structure is a priority, GICs serve as a durable restoration, bonding chemically to the tooth structure, and avoiding unnecessary beveling of enamel One of the major limitations of conventional GICs is the inconvenient setting characteristics and low abrasive resistance that is overcome by resin-modified GICs (RMGICs)

165. RESIN MODIFIED GLASS IONOMERS (RMGIC’s) Improved setting characteristics allowing sufficient working time that can be shortened by light curing to make it more resistant to effects of moisture while simultaneously developing rapid early strength. In comparison to the conventional GICs, the translucency is markedly superior with better color matching. RMGICs have a better adhesion to dentine and allow for easy repairs to defective or damaged surfaces of the restoration. They also bond directly to composite resin making them ideal cement for “sandwich” technique reduced superficial degradation, and increased wear resistance , Superior fluoride release

166. Belluz M, Pedrocca M, Gagliani M. Restorative treatment of cervical lesions with resin composites: 4-year results. Am J Dent 2005;18:307-10 COMPOSITES Exhibiting improved adhesion to the tooth Higher abrasive resistance Disadvantages Deficient marginal seal and progressive degradation of adhesion The polymerization shrinkage of the composites is the main cause for microleakage, poor marginal adaptation, and low retention rates Loss of retention due to cervical stress/flexure Flowable composites have been introduced that has low quantities of filler, low modulus of elasticity, and more flexible to dislodging forces

167. COMPOMERS The main aim of using compomers is to avoid the use of acid etching of enamel while retaining the elasticity of composites, hydrophilic, and fluoride-releasing properties of the GICs. Increased elasticity in comparison to GIC – better performance in stress bearing areas Brackett WW et al. 1-year clinical evaluation of compoglass and fuji II LC in cervical erosion/abfraction lesions. Am J Dent 1999 Disadvantage The lack of enamel etching has lead to decreased bond strength and less retention rates Folwaczny M, Loher C, Mehl A, Kunzelmann KH, Hickel  R. Class  V lesions restored with four different tooth- colored materials--3-year results. Clin Oral Investig 2001

168. GIOMERS AND ORMOCERS Giomers are fluoride-releasing resin materials with “ prereacted glass,” a hybrid of glass-ionomer and resin-based composite. Better color match, decreased microleakage, and increased fluoride release. They have a better surface finish and esthetic properties comparable to composites ( Sunico MC, Shinkai K, Katoh Y. Two-year clinical performance of occlusal and cervical giomer restorations. Oper Dent 2005)

169. Ormocers are organically modified ceramics consisting of a polycondensed three-dimensional cross-linked organic/inorganic network ( polysiloxanes ), organic polymers, and glass/ceramic filler particles. Better marginal adaptation and integrity. Hennig AC, Helbig EB, Haufe E, Richter G, Klimm HW. Restoration of class  V cavities with the ormocer -based filling system admira . 2004

170. Activa BIOACTIVE RESTORATIVE ( Pulpdent corporation, Watertown, MA) Dual cured material It is the first dental material with bioactive resin matrix, shock absorbing resin component and reactive glass ionomer fillers designed to mimic physical and chemical proeprties of natural teeth Highly esthetic bioactive hydrophilic composite that bonds chemically to the tooth , seals against microleakage and releases more Ca. PO4 and F ions It is more bioactive than GIC and more durable and fracture resistant than composites It is well preferred for cervical lesions Bioactive Restorative vs GIC modified glass ionomer in restoration of cervical lesions: A randomized controlled trial. 2020

171. Conventional Fixed Restoration’s The main options either individually or in combination are: Opposing tooth reduction Elective endodontic treatment and post retention Occlusal adjustment Periodontal surgical crown lengthening Localized orthodontic tooth movement (Conventional Fixed Appliance or ‘Dahl’ appliance) Overall increase in occlusal vertical dimension

172. One of the more satisfactory and conservative ways of recreating space, particularly in situations of localized anterior tooth wear, is by orthodontic tooth movement – by fixed or removable metal-based anterior bite plane being an established method or more often today the use of direct composite resin techniques. The so-called Dahl appliance , achieves space recreation by a combination of anterior tooth intrusion and posterior tooth extrusion. This localized orthodontic treatment provides the opportunity to maximize the appearance and function of the subsequent crowns and preserves tooth tissue. Localised anterior tooth wear .‘Dahl appliance’ Inter-incisal space recreated following the removal of the ‘Dahl appliance by posterior teeth extrusion

173. In certain situations where there is generalized tooth wear and sufficient indications to consider crown restorations for the posterior teeth, a full mouth crown reconstruction at an overall increase in occlusal vertical dimension will usually provide adequate space for anterior restorations Generalised tooth wear restored with conventional crown restorations in the anterior and posterior segments at an overall increase in occlusal vertical dimension

174. Removable Onlay/Overlay Prostheses The use of a removable onlay/overlay prosthesis can be a valuable means of rehabilitating patients with moderate/severe tooth wear, particularly when there are also missing strategic teeth to be replaced. Advantages:- Simple Non – invasive Cost effective The construction of a provisional acrylic resin removable prosthesis is recommended initially, allowing the opportunity to carry out modifications to the shape, position and occlusal relationship of the prosthetic teeth and soft tissues, as well as assessing the patient’s tolerance of a removable prosthesis.

175. This does not require tooth preparation but long term use requires tooth preparation often incorporating a cobalt-chromium framework. It is possible to achieve an increase in occlusal vertical dimension with the use of a removable posterior onlay prosthesis in combination with anterior fixed crown restorations Disadvantages:- Maintenance demands are relatively high Material wear and fracture Complex design Unesthetic

176. Examples of overlay removable prostheses: ( a ) Full labial flange, ( b ) gingival fitting anterior tooth facings The use of a metal framework incorporating incisal and occlusal coverage used to strengthen removable onlay/overlay prostheses for patients demonstrating signifi cant parafunctional clenching/grinding habits

177. Periodontal Therapy Periodontal therapy is required when non – carious lesions are associated with considerable gingival recession and mucogingival defects. Treatment protocol is as follows: - Supragingival and subgingival scaling Restorative treatment for non carious lesions Frenectomy and fenestration procedure for deepening the vestibule Evaluation of increase in the width of attached gingiva Root coverage procedures Using free gingival grafts or connective tissue grafts Using non grafting procedures like rotational or coronally advanced flaps or guided tissue regeneration (Interdisciplinary approach for the management of Non – Carious lesions, Journal of Indian Society of Periodontology, 2015 )

178. Classification and Treatment of the Anterior Maxillary Dentition Affected by Dental Erosion: The ACE Classification Francesca Vailati . The International journal of periodontics & restorative dentistry · 2010

179. Yellowish at the centre due to the underlying dentin and whitish periphery due to thick enamel 100% recovery possible Preventive measures – guard, Fluoride Determining the etiology is essential To protect remaining enamel and dentin – D/I composite If interocclusal space is less- VDO increased by ortho intervention Direct or indirect composite can be given based on severity and financial aspect Direct composite or onlays in posteriors Palatal veneers when there is adequate interocclusal space

180. At this stage, posteriors (especially premolars) are also involved Palatal aspect restored with composite veneers and facial aspect with ceramic veneers Sandwich technique is called experimental because ceramic facial veneers are bonded to reduced dentin surface Prognosis may be unfavourable Sandwich approach can still be used to preserve pulp vitality, preserve rem tooth structure If pulp vitality s lost thereafter, endodontic treatment through palatal veneer

181. COMBINED LESIONS Grippo et al . ABFRACTION, ABRASION, BIOCORROSION, AND THE ENIGMA OF NCCLS. Journal of Restorative and Esthetic Dentistry. 2012

182. Attrition- Abfraction. Attrition- abfraction is the joint action of stress and friction when teeth are in tooth-to-tooth contact, as in bruxism.

183. Abrasion-abfraction. Abrasion-abfraction is the loss of tooth substance caused by friction from an external material on an area in which stress concentration due to loading forces may cause tooth substance to break away. Such a synergistic tooth-destructive effect may be observed cervically when toothbrushing abrasion exacerbates abfraction to produce wedge-shaped lesions.

184. Erosion-abfraction Erosion (Bio Corrosion)-abfraction is the loss of tooth substance due to the synergistic action of a chemical corrodent on areas of stress concentration. This physicochemical mechanism may occur as a result of either sustained or cyclic loading and leads to static stress corrosion or cyclic stress corrosion

185. A ttrition-Corrosion Attrition-corrosion is the loss of tooth substance due to the action of a corrodent i n areas in which tooth-to-tooth wear occurs. This process may lead to a loss of vertical dimension, especially in patients with GERD or gastric regurgitation . An occlusal or incisal pattern of wear develops.

186. Abrasion-corrosion Abrasion-corrosion is the synergistic activity of corrosion and friction from an external material. This could occur from the frictional effects of a toothbrush on the superficially softened surface of a tooth that has been demineralized by a corrosive agent. Teeth that are out of occlusion could be affected by this mechanism and develop cervical lesions

187. Biocorrosion-abfraction Biocorrosion (caries)-abfraction is the pathological loss of tooth structure associated with the caries process, where an area is micromechanically and physicochemically breaking away due to stress concentration. A common site for this synergistic activity is the cervical area of the tooth, where it may be manifested as root or radicular caries.

188. MANAGEMENT OF WORN DENTITON Cervical Tooth Wear Materials can either be composite resin or glass ionomer-based , or a combination of both; either in a layered technique with the individual materials or with formulated R esin- M odified glass-ionomer cements. Textbook of Erosion and its Clinical Management, Bennett T

189. Alternatively, a glass-ionomer cement restoration with inherent bonding properties to both dentin and enamel may be considered. The new generation of light-activated resin-modified glass-ionomer combines superior properties of both composite resin and conventional glass-ionomer cements.

190. Palatal Tooth Wear This pattern of tooth wear is usually characteristic of acid erosion, possibly combined with a degree of attrition Often, the labial and incisal surfaces are relatively intact and the main indications for restorative treatment are to offer some resistance to further palatal tooth wear which will reduce the risk of significant enamel fractures The use of resin-bonded palatal metal alloy veneers is an acceptable method to manage this form of tooth wear and has been shown to be a relatively durable technique.

191. Either heat treated gold alloys or nickel-chromium alloys, as used in resin-bonded bridge frameworks, are currently the cast metal alloys of choice. The use of nickel/chromium alloy resin-bonded palatal veneers used to restore localised palatal tooth wear for maxillary incisor teeth

192. Combined Incisal and palatal tooth wear In these circumstances, it is feasible to build up the incisal portion of the tooth with direct acid-etch retained composite resin and then construct a resin-bonded metal alloy palatal veneer to cover both the palatal tooth tissue and composite resin. An alternative and very conservative approach is to restore both the incisal and palatal tooth surfaces with direct acid-etch retained composite resin at an increase in occlusal vertical dimension to accommodate the thickness of the restorative material Modified porcelain laminate veneer restorations of both the incisal and palatal worn tissue have also been suggested

193. Restoration of incisal and palatal aspects of worn upper anterior teeth with direct composite resin restorations a,c -Before restoration b,d -After restoration

194. Combined Labial/Incisal/Palatal Tooth Wear Use of a labial porcelain laminate veneer in conjunction with a metal alloy veneer for the palatal surface, or an adhesive metal-ceramic crown restoration. All these techniques are relatively complex and would normally require some inter-occlusal space creation prior to completion of the restoration. In these circumstances, consideration should be given to the provision of a more conventional full coverage crown . In case of advanced wear of anterior mandibular teeth , it may be advantageous to consider a degree of localized crown lengthening surgery in an attempt to capture all remaining tooth enamel

195. Posterior and generalized tooth attrition If aesthetics dictates then a resin-bonded ceramic or indirect composite resin onlay can be considered In situations of generalized tooth wear where there are indications to consider a full mouth reconstruction of the dentition, then the use of Porcelain laminate veneers for anteriors and adhesive onlay restorations in the posterior quadrants can be of value in certain circumstances. If there is insufficient interocclusal space, some occlusal tooth reduction may also be necessary. Where space is at a premium, the selection of a gold alloy as opposed to porcelain will be advantageous

196. it is possible to consider a full mouth reconstruction of the worn dentition using resin-bonded ceramic or indirect composite resin restorations The use of a full coverage occlusal splint to be worn chiefly at night may offer some protection to vulnerable restorations. Reconstruction of a worn maxillary dentition using modified resin-bonded laminate porcelain veneers for the anterior teeth, and resin-bonded bridges and onlays for the posterior teeth

197. SOME OF THE NON-CARIOUS LESIONS ARE:- Attrition Abrasion Erosion Abfraction Localized non hereditary enamel hypoplasia Localized non hereditary enamel hypocalcification Localized non hereditary dentin hypoplasia Localized non hereditary dentin hypocalcification Amelogenesis imperfecta Dentinogenesis imperfecta DEVELOPMENTAL DEFECTS

198. LOCALIZED NON - HEREDITARY ENAMEL HYPOPLASIA During enamel formation , AMELOBLASTS are injured/irritated, enamel matrix, would not be properly formed resulting in formation of either Hypoplastic or Hypomineralized enamel When the teeth erupt,these defects will be apparent in the crown portion of teeth (tooth) which is called as Localized Non Hereditary Enamel Hypoplasia

199. CAUSES :- Localized disorders P eriapical infections of the preceding deciduous tooth (Turner’s hypoplasia T raumatic intrusion of the preceding deciduous tooth etc Systemic disorders: Exanthematus diseases NutritionaL deficiencies(especially vitamins A,C and D) Hypocalcemia Microbial process e.g . (syphilis) Fluorides : Metabolizing fluorides in excessive amounts could poison the ameloblasts and disturb their activities to variable degrees, leading to mottled enamel or a completely disfigured crown

200. CLINICAL PRESENTATION Isolated pits to widespread linear defects, depressions, or loss of a segment in the enamel . These defective areas will have different color from the surrounding enamel. In contrast with the caries and erosion and abrasion lesions, enamel hypoplasia does not progress

201. TREATMENT If defects are minimum ( narrow lines /isolated pits /shallow depressions) - then S elective O dontomy /Esthetic R eshaping can be performed . If odontomy and esthetic reshaping of the tooth enamel can’t produce a pleasing functional effect, then- Direct tooth colored Composite resin is inserted with /without tooth preparation Defect at occluding or contacting area- resort to Metallic Or Cast Restorations.

202. In d iscolored lesions, Vital Bleaching can be attempted after odontomy and before acid conditioned enamel. Disfiguring lesion, if not in occlusion - Laminated Tooth- Colored Resinous Or Ceramic Veneer are treatment of choice

203. LOCALIZED NON - HEREDITARY ENAMEL HYPOCALCIFICATION Hypomineralized enamel results when normal amount of enamel matrix fails to achieve full mineralization and is a usual consequence of damage to ameloblasts CAUSES:- Childhood fever, Trauma / Fluorosis during developmental stages of tooth formation

204. CLINICAL PRESENTATION:- Appear chalky S oft to indentation. Stainable - chalky to yellow, to brown, dark brown and or greyish If extensive- these lesions predispose to attrition and abrasion. Enamel chipped if lesion involves the entire surface of a tooth .

205. TREATMENT If diagnosis is made early in tooth’s life ,while the uncalcified enamel is still intact, an attempt at remineralization should be made. This can be done using- F luoride applications Fluoride iontophoresis S trict prevention of plaque accumulation in these areas Other mode of treatment include: Vital bleaching Laminated veneering Composite Crowns

206. LOCALIZED NON - HEREDITARY DENTIN HYPOPLASIA Odontoblasts are the specialized cells Any disturbance in their function - deficient or complete absence of dentin matrix deposition, Leads to the development of Localized Non- Hereditary Dentin Hypoplasia CAUSE:- It appears to be a hereditary disease, transmitted as an autosomal dominant characteristics

207. CLINICAL PRESENTATION There would be NO apparent destruction to be diagnosed or treated ,till the time the lesion is covered with enamel During tooth preparation for a restoration , these defects may get exposed TREATMENT Various intermediary bases that can be used are : Zinc oxide eugenol Calcium hydroxide Zinc phosphate cement Polycarboxylate cement Varnishes Glass ionomer cement

208. LOCALIZED NON-HEREDITARY DENTIN HYPOCALCIFICATION In hypocalcification, there is failure of union of many globules, the dentin will be present in substance but would be softer ,more penetrable , and less resilient CAUSES:- a)Systemic disorders b) Localized disorders c) Fluorides CLINICAL PRESENTATION and TREATMENT similar to dentin hypoplasia

209. AMELOGENESIS IMPERFECTA It is a congenital disorder which presents with a rare abnormal formation of the enamel or external layer of the crown of teeth, unrelated to any systemic or generalized conditions It is an autosomal dominant or autosomal recessive disorder 4 types (Based on enamel defects):- Hypoplasia Hypocalcification Hypomaturation Hypomaturation –hypoplasia with taurodontism

210. HYPOPLASTIC AMELOGENESIS IMPERFECTA THIN ENAMEL DELAY IN ERUPTION OPEN CONTACT ENAMEL IS GLOSSY. MAY LOOK WRINKLED MISSING TEETH SEVERE OCCLUSAL WEAR

211. HYPOCALCIFIED AMELOGENESIS IMPERFECTA ENAMEL IS STAINED (YELLOW/BLACK) SEVERE ATTRTION OF ENAMEL ENAMEL CHIPS OFF EASILY STAINS BECOME DARKER WITH TIME ENAMEL SOFT IN CONSISITENCY

212. HYPOMATURATION AMELOGENESIS IMPERFECTA Affected teeth ---normal in shape Normal thickness of enamel But is softer than normal ,tends to chip off E xhibit mottled, opaque white brown –yellow discoloration rough surface of the teeth

213. AIMS OF THE TREATMENT- Reducing tooth sensitivity Improving esthetics Correcting or maintaining vertical dimension Restoring masticatory function PHASES IN THE TREATMENT OF AI Temporary phase –undertaken during primary or mixed dentition Transitional phase –when all the permanent teeth have erupted Permanent phase – occurs in adulthood TREATMENT - Marzouk

214. Reducing tooth sensitivity- Topical fluoride products - CPP-ACP products Dietary modification Maintaining good oral hygiene Correcting or maintaining vertical dimension – Placement of GIC ( sensitivity ,if any ) on grossly worn down molars followed by placement of composite restorations ,assist in restoring the occlusal vertical dimension Esthetic improvements Bonding direct or indirect resin composite restorations MANAGEMENT OF AI

215. Treatment of Hypoplastic Amelogenesis Imperfecta:- Use of Bonding Procedures to protect the malformed teeth from caries and to improve esthetics Hypoplastic teeth usually have well mineralized pitted enamel, making them suitable for restorative procedures involving bonding to enamel Orthodontic therapy may be used to partially close the interdental spaces prior to restoration.

216. Composite resin or porcelain veneers can be bonded to the anterior teeth when the incisor shape, size and/or color require modification. However, if the enamel is extremely thin and malformed the teeth can require full dental coverage with crowns .

217. Treatment of Hypomaturation and Hypocalcified amelogenesis imperfecta: If e namel is not severely involved - Conventional Bonded restorations If enamel is severely hypomineralized and is of insufficient strength to retain bonded or intracoronal restorations - Full Coverage Restorations Esthetic anterior restorations can be made using variety of techniques: Open faced stainless steel crowns with composite inserts Composite restorations can great ly reduce sensitivity and provide reasonable esthetics Resin crowns can be placed on permanent incisors soon after they begin to erupt during the mixed dentition (about age 7 - 10 years)

218. As the gingival margin becomes exposed during continued tooth eruption, the resins can be easily modified by adding them to the gingival margin of the tooth Ultimately, Custom Fabricated Crowns can be placed on the dentition

219. DENTINOGENESIS IMPERFECTA It is an autosomal dominant disorder Primary teeth are normally more severely affected than permanent teeth It is of 3 types:- ( Witkops Classification) Type I – Dentinogenesis imperfecta with Osteogenesis Imperfecta Type II – Dentinogenesis imperfecta without Osteogenesis Imperfecta (Hereditary Opalescent dentin) 3. Type III - Brandy wine type (Shell teeth )

220. CLNICAL FEATURES:- Dentitions have grey to brownish or yellowish brown discoloration , with a distinctive translucence or opalescent hue Enamel may be lost early through fracturing away because of abnormal DEJ D entine often demonstrates significantly accelerated attrition. Teeth are prone to fracture The pulp is usually obliterated by the excess dentine production, some of the teeth may show the normal sized pulp (shell tooth).

221. RADIOGRAPHIC FEATURES: Type I and II are radiographically similar and often exhibit “Bulb shaped” or “Bell shaped crowns” of the teeth with abnormally constricted cervical areas Varying degrees of obliteration of the coronal as well as radicular pulp chamber

222. Type III – affected teeth exhibit extremely large pulp chambers surrounded by a thin shell of dentin and enamel Because of their typical appearance, they are often called “Shell teeth” These teeth frequently exhibit multiple pulp exposure and associated periapical pathology

223. MANAGEMENT:- Any possible success for treatment depends upon early diagnosis and care. In the primary dentition- Stainless steel crowns on the molars, to prevent tooth wear and maintain the occlusal vertical dimension. Permanent dentition Cast occlusal onlays on the first permanent molars . If conventional Root canal therapy is not an option, periapical curettage and retrograde root filling is another possible alternative, but is not recommended for teeth with short roots Until growth is complete, the treatment of choice for the replacement of missing teeth is dentures.

224. In case of severe generalized attrition, complete denture prosthesis may be necessary. Metal and ceramic crowns are given Dental implants may be considered when growth is complete at about 18 years of age

225. TRAUMA AND FRACTURES

226. The cause of fractures may include : Physical trauma Occlusal prematurities Repetitive heavy and stressful chewing Resorption weakened teeth Iatrogenic dental treatment It has been suggested that the determination of a fractured tooth is often more of a prediction rather than a definitive diagnosis based on a collective analysis of subjective and objective findings. Five types of longitudinal fractures have been described (American Association of Endodontists,2008 ): CRAZE LINES Affect only the enamel, originate on the occlusal surface, are typically from occlusal forces and are asymptomatic FRACTURED CUSP occur on the cusps and cervical margins of the root can have acute pain to mastication and cold.

227. CRACKED TOOTH occurs on the crown and may extend into the root , develop from damaging occlusal forces or weakened tooth structure VERTICAL ROOT FRACTURE occur and originate only in the roots, have variable but a lesser degree of signs and symptoms caused by wedging forces within the roots (i.e. RC obturation or posts)

228. SPLIT TOOTH a fracture through the crown and roots, developing from damaging occlusal forces or weakened tooth structure, separating the tooth into two segments, with the tooth typically being painful to mastication

229. Cracked teeth are thought to occur as a result of parafunctional habits or from weakened tooth structure The symptoms that develop subsequent to these cracks have been termed as ― Cracked Tooth Syndrome This has been described as acute pain that results during the mastication (or release) of small hard food substances and also exacerbates with cold. (Cameron CE,JADA,1964 : American Association of Endodontists,2008)

230. In summary there are two main groups of Fractured teeth : Tooth infarctions :(incomplete tooth fractures extending partially through a tooth ) that includes Craze lines Cuspal fractures Cracked teeth B) Vertical root fractures : (that occur in endodontically treated teeth )

231. DIAGNOSIS Begins with the chief complaint i.e. pain on chewing ,elevated sensitivity to cold food and sweets Absence of carious etiology …trigger a suspicion of infarction Visual examination by Transillumination and Dyes (methylene blue) An y existing restor a tio n i n th e to o t h should be removed to reveal the infarction lines

232. Cold stimulus application and Electric pulp testing(EPT ) : Gives information about the pulpal status ,teeth with infarctions respond to a lower threshold to cold and EPT as compared to the non cracked teeth . Cameron suggested the use of thin sharp explorer tip to probe around the cervical circumference of the suspected teeth….the click of the explorer‘s tip and the patient‘s response can provide a clue Removal of the restoration and highlighting with the dye to detect infarction Note that the beam of light does not cross the infarction

233. BITING TEST Biting on rubber wheels, cotton tip applicators ,moist cotton, commercial biting appliances like tooth sloth. Tooth sloth - Differentiates biting pain from restorations with microleakage /pain from infarction…… In case of cracked tooth, pain is felt on release of pressure rather than on biting

234. RADIOGRAPHIC EXAMINATION The fractures are incomplete, tend to present in a mesial --distal orientation and are generally centered on the occlusal table ,radiographs are not very diagnostic . Even cone beam volumetric tomography (CBVT) scans cannot consistently visualize these fractures, the coronal-apical progression of fractures cannot always be objectively assessed until the tooth has been extracted.

235. TREATMENT Aims : Preventing the separation of the hard tissue entities Keeping the bacteria's from colonizing the space caused by infarction I mmediate reduction of occlusal contacts by selective grinding at the site of the crack or against the cusp or cusps of the occluding antagonist. It is not clear whether all the teeth with infarction require root canal therapy, it depends on the extent of the fracture. Extraction is preferred in case of extensive fractures Grossmans Endodontic Practice. 13 th edition

236. Treatments are mainly designed to bind the infarcted segments of teeth together .,that includes the use of Adhesives Full Coverage Crowns If the patient has an incomplete fracture of only the enamel and dentin, a full-crown restoration immobilizing the fragments may be successful. Definite treatment of a cracked tooth attempts to preserve pulpal vitality by requiring full occlusal coverage for cusp protection

237. Cusp coverage as a treatment plan may seem as an invasive treatment, but a vertical crack that is left unprotected will migrate pulpally and apically. When the ageing defect encroaches on the pulp, emerging endodontic symptoms consistent with irreversible pulpitis are indicative of the unavoidable need for root canal treatment. Orthodontic band was placed to bind the crown together . After 3 weeks the tooth was completely asymptomatic and Tooth was restored with a full coverage crown

238. Ellis and Davey Classification of Dental trauma and its management . Class I – simple fracture of crown involving only enamel Class II- extensive fracture of crown with considerable amount of dentine, with no pulp exposure Class III- extensive fracture of crown, with dentinal involvement and pulp exposure Class IV- traumatized tooth becomes non vital with or without loss of crown structure Class V – tooth lost due to trauma Class VI- fracture of root with or without crown fracture Class VII – displacement of the tooth without crown or root fracture Class VIII – fracture of the crown en masse Class IX- fracture of deciduous teeth

239. Management Smoothening, Recontouring of rough edges If a tooth fragment is available, it can be bonded to the tooth. If not Restoration with composite resin ENAMEL FRACTURE Management If a tooth fragment is available, it can be bonded to the tooth. Otherwise, E xposed dentin can be sealed with glass ionomer or a more permanent restoration using a bonding agent and composite resin ENAMEL AND DENTIN FRACTURE

240. VITAL PULP THERAPY : O pen apex PULP CAPPING (fresh exposure <24 hr) PARTIAL PULPOTOMY FULL PULPOTOMY Closed apex PARTIAL PULPOTOMY PULPECTOMY NON VITAL PULP THERAPY : Open apex – APEXIFICATION, REVASCULARISATION Closed apex -PULPECTOMY PULP EXPOSURE

241. CROWN - ROOT FRACTURE Emergency treatment Stabilization of the coronal fragment with an acid etch/resin splint to adjacent teeth Vertical crown root fractures must generally be extracted Non - Emergency treatment Gingivectomy Orthodontic extrusion Surgical exposure Extraction

242. ROOT FRACTURE Coronal third fracture B elow the alveolar crest - permanent fixation of the coronal fragment to adjacent non‐injured teeth with a lingual orthodontic retention wire C lose to gingival crevice - Removal of the fragment and subsequent orthodontic or surgical extrusion of the remaining apical fragment. If not possible to treat – extracted Middle and apical third fracture Revascularization is possible if segments are well re-approximated In more apical root fracture, endodontic therapy can be carried out if remaining coronal segment is long enough C oronal segment with compromised attachment –Post or Endodontic implants can be used to provide additional support to tooth

243. RESORPTION

244. Physiologic resorption is seen in primary teeth that results in their exfoliation and allows eruption of their permanent successors. Pathologic resorption can occur following T raumatic injuries, O rthodontic tooth movement, or Pressure from impacted teeth, tumors or cyst

245. SURFACE RESORPTION Resorption in the cementum and the outermost layers of the dentin without an inflammatory reaction in the PDL. [ Andreason & Hjorting – 1966 ] Etiology: Caused by injury restricted to external root surface. Resorption can occur due to- ACUTE CAUSES Concussion Subluxation Lateral luxation Intrusion Replantation of avulsed teeth

246. CHRONIC CAUSES Orthodontic tooth movement Chronic injury affecting PDL Traumatic occlusion Pressure from developing cyst /apical granuloma/ectopically erupting tooth F uss et al. Root resorption – Diagnosis, classification and treatment options based on stimulation factors. Journal of Dental Traumatology, 2003

247. ORTHODONTIC TOOTH MOVEMENT Root resorption increases with the period of force application. The severity of root resorption is highly influenced by the - Amount of tooth movement and the force regimen. - The more teeth are displaced, more the resorption - Intermittent forces cause less severe root resorption It mostly affects apical third of the root Teeth are usually asymptomatic and pulp is mostly vital unless the pressure is high, which disturbs the apical blood supply

248. IMPACTED TEETH/ TUMORS/CYST When impacted teeth attempt to erupt, resorb the roots or crowns of adjacent teeth by pressure. Similarly in case of tumors or cyst in the apical region Predentin and Odontoblastic layer is most resistant to this resorption and the pulps of these teeth remain uninflamed. Pressure damages the cementum and provides the continuous stimulus for the resorbing cells. Removal of the stimulation factor i.e pressure is the treatment of choice for resorption caused by pressure due to orthodontic tooth movement, impacted tooth or tumor

249. It occurs most frequently as a result of complication following avulsion in which the periodontal ligament dries and loses its vitality EXTERNAL REPLACEMENT RESORPTION The most frequent cause appears to be acute trauma (severe luxations such as lateral luxations , intrusions, and replantation of avulsed teeth).

250. In those situations, the homeostasis of the PDL is lacking. Healing events from the bony alveolus result in creation of a bony bridge between the socket wall and the root surface CLINICAL FINDINGS Patient is usually asymptomatic Clinically, tooth appears to be in infraocclusion High metallic sound on percussion

251. TREATMENT In adolescents, the ankylosed tooth will fail to erupt and will gradually go into infraposition . The younger the age, the more pronounced is the infraposition . Presently, there are five treatment approaches: 1. Decoronation (to maintain and augment the alveolar process) 2. Luxation of the tooth (breaking of ankylosis sites) 3. Vertical distraction 4. Prosthetic elongation 5. Acceptance of the resorbing tooth Of the above approaches, the decoronation treatment is very suitable in children and adolescence, when significant remaining alveolar growth is expected.

252. EXTERNAL CERVICAL ROOT RESORPTION According to Heithersay E xternal root resorption associated with marginal periodontitis without pulpal involvement Etiological factors 23% were related to orthodontic treatment, 15% to acute trauma, 14% to a cervical restoration. Oral surgery 6% Intracoronal bleaching 5% Other factors: Periodontal therapy, Bruxism, Intracoronal restorations, Delayed eruption etc

253. A pink or red discoloration may develop at the cervical region of the tooth; when present, due to the fibrovascular granulation tissue occupying the resorptive defect MANAGEMENT Restore the hard tissue defect surgically or non-surgically with aesthetic biocompatible restorative material Endodontic therapy if the resorptive process has perforated root canal wall

254. CONCLUSION Because of improved caries prevention, greater awareness of the importance of preserving all masticatory units, and change in the life style and dietary habits, we might face increased frequency of non carious lesions Depending on the degree of tooth wear, restorative treatment can range from placement of bonded composites in a few isolated areas of erosion, to full mouth reconstruction in the case of the devastated dentition.  Regardless of the type of restorative therapy provided, prevention of the progression of tooth wear should be the basis of management. 

255. This will increase the likelihood of successful, long-term outcomes of the restorative treatment. Thus, apart from regular monitoring of the aetiology and development of these lesions, improved measures of prevention and therapy still need to be introduced.

256. Art and science of operative dentistry- Sturdevant 5 th edition Operative Dentistry- Modern Theory and Practice: Marzouk Shafer‘s Textbook of Oral Pathology- Shafer, Hine, Levy Abfraction : separating fact from fiction --ADJ 2009 Textbook of erosion and its clinical management. Bennett T Non carious cervical lesions and abfractions :A re-evaluation –JADA 2003 ;134:845—850 Role of erosion in tooth wear :aetiology ,prevention and management ---IDJ(2005) 55,277-284 REFERENCES

257. Grippo JO, Simring M, Schreiner S. Attrition, abrasion, corrosion and abfraction revisited. J Am Dent Assoc 2004;135:1109-18 Erosion –Chemical and biological factors of importance –IDJ (2005 ) 55 285-290 Removable Orthodontic Appliances— K.G.Isaacson Nascimento MM et al. Abfraction lesions: etiology , diagnosis, and treatment options. Clinical, cosmetic and investigational dentistry. 2016;8:79