Dental Caries: An Evidence-Based Overview for Students and Practitioners. Comprehensive PPT on dental caries covering etiology, pathogenesis, diagnosis, and treatment with preventive and pediatric focus

This presentation offers a comprehensive, evidence-based overview of Dental Caries (Tooth Decay) — covering its causes, mechanisms, clinical presentation, diagnostic methods, and modern preventive and restorative management strategies. It serves as a complete learning resource for undergraduate and postgraduate dental students, general practitioners, and pediatric dentists aiming to strengthen their conceptual and clinical understanding of the disease.

The PPT begins with an introduction to Dental Caries as a multifactorial, infectious, and dynamic disease process resulting in the destruction of dental hard tissues by acid-producing bacteria. It explores the historical background and definitions, tracing the shift from the traditional “specific plaque hypothesis” to the ecological plaque hypothesis that explains the balance between demineralization and remineralization.

Next, it delves into the etiopathogenesis of dental caries, describing the interplay between microbial flora (Streptococcus mutans, Lactobacillus species), dietary sugars, salivary composition and flow, and host susceptibility. The presentation also explains the Stephan curve and critical pH (5.5) that dictate enamel dissolution, supported by visual diagrams and flowcharts for conceptual clarity.

A detailed discussion follows on the morphology and clinical stages of carious lesions, starting from incipient white-spot lesions to frank cavitation. The presentation outlines the histopathology of enamel, dentinal, and root surface caries, emphasizing early diagnosis and minimally invasive interventions.

The classification systems covered include Black’s classification, the WHO system, and the International Caries Detection and Assessment System (ICDAS), allowing students to correlate clinical findings with modern diagnostic criteria.

Further sections include the diagnostic aids in caries detection, such as:

Visual-tactile examination

Bitewing and periapical radiography

Fiber-optic transillumination (FOTI)

Laser fluorescence (DIAGNOdent)

Quantitative Light-Induced Fluorescence (QLF)

Emerging tools like AI-based caries detection

In terms of management, the PPT covers both preventive and operative approaches. Topics include:

Fluoride therapy (topical, systemic, varnishes, and dentifrices)

Pit and fissure sealants

Dietary modification and counseling

Use of remineralizing agents (CPP-ACP, nano-hydroxyapatite)

Atraumatic Restorative Treatment (ART)

Silver Diamine Fluoride (SDF) and its role in arresting early caries

Minimal Intervention Dentistry and CAMBRA (Caries Management by Risk Assessment) protocols

Special attention is given to Pediatric Dentistry and Preventive Oral Health, discussing caries in primary teeth, Early Childhood Caries (ECC), and the importance of parental education, recall systems, and anticipatory guidance in managing caries risk in children.

The final portion presents the public health significance of dental caries, epidemiological trends in Indi

1. Dental caries Presented by: Dr.Atharva Babel Dr. Babel’s Unique Dental Clinic, Pimple Saudagar

2. Contents Introduction Definition Classification Theories of dental caries Etiology of dental caries

3. Introduction Oral health is one component of general health and is an important factor in the normal development of a child. Caries is a biosocial disease rooted in the technology and economy of our society. As the living standards improve the severity of the disease usually increases.

4. In the industrialized countries dental caries is the most abundant disease. It is becoming increasingly clear that the only hope for reducing the burdens of dental ills is through its prevention.

5. According to Ernest Newburn (1989) Dental caries is defined as a pathological process of localized destruction of tooth tissues by micro - organisms. According to Hume (1993) Caries is essentially a progressive loss by acid dissolution of the apatite component of the enamel or the cementum then dentin. Definition

6. According to Shafer (1993) It is defined as an irreversible microbial disease of the calcified tissues of the teeth, characterized by demineralization of the inorganic portion and destruction of the organic substance of the tooth , often leading to cavitation. According to Sturdevant (2002) Dental caries is defined as an infectious microbial disease of the teeth that results in localized dissolution and destruction of the calcified tissues .

7. According to World Health Organization (2005 ) Localized post eruption, pathologic process of external origin involving softening of hard tooth tissue and proceeding to the formation of a cavity.

8. According to International caries detection and assessment system (ICDAS) Classification of Dental Caries

9. Classification of Dental Caries

10. Classification of Dental Caries

11. Morphology of fissures (Nagano, 1961) U type (14%) V type (34%) I type (19%) IK type (26%) Inverted Y type (7%)

12. Classification of Dental Caries

13. Classification of Dental Caries

14. According to pathway of caries Forward caries If the caries cone in enamel is larger or of the same size as that in dentin it is referred to as forward caries. Classification of Dental Caries

15. Backward caries Whenever the spread of caries along the DEJ exceeds the carious cone in enamel, the caries extend into the enamel from the junction. Such caries are called backward caries.

16. Classification of Dental Caries

17. According to World Health Organisation (WHO) In this classification the shape and depth of the caries lesion scored on a four point scale

18. According to Graham Mount This is a recent classification based on the site, size and complexity of the caries. Cavity size Size 1 Size 2 Size 3 Size 4 Minimal Moderate Enlarge Extensive Site 1 Pit and fissure 1.1 1.2 1.3 1.4 Site 2 Contact area 2.1 2.2 2.3 2.4 Site 3 Cervical region 3.1 3.2 3.3 3.4

19. Theories of dental caries Legend of the worm theory Tooth ache was caused by a worm that drank blood of the teeth and fed on the roots of jaws Discovered on one of many clay tablets excavated in the Euphrates Valley Estimated to be from about 5000 BC “ Guy de Chauliac ” the greatest surgeon of the middle ages also believed that worms caused dental decay

20. Cure for Dental decay according to Guy de Chauliac (1300-1368) Fumigation with seeds of leek, onion and Hyoscyamus Antony van Leeuwenhoek (1700) “ The father of modern microscopy” wrote a letter to the Royal Society of London describing “little worms taken out of a corrupt tooth” Stating that they caused dental decay

21. Humoral theory Ancient greeks considered that a person’s physical and mental constitution was determined by the relative proportions of the four elemental fluids of the body.

22. Hippocrates drew attention to the stagnation of food and suggested that Both local and systemic factors were related to the cause of caries Aristotle noticed that soft, sweet figs adhered to the teeth and, putrified and produced damage

23. Vital theory Regarded dental caries as originating from the tooth itself Proposed at the end of the 18 th century remained dominant until the middle of the 19 th century According to this theory:- A clinically well known type of caries is characterised by extensive penetration into the dentin, and even into the pulp but with a barely detectable catch in the fissure

24. Chemical theory Parmly (1819)- Proposed that an unidentified “ chymical agent” was responsible for caries Stated that caries began on the enamel surface in locations where food putrified and acquired sufficient dissolving power to produce the disease chemically Robertson (1835) and Regnart (1938) carried out experiments with different dilutions of inorganic acids and found that they corroded enamel and dentin

25. Parasitic or septic theory Dubos (1954) Postulated the possibility of micro organisms having toxic and destructive effects on the tissue Erdl  (1843) described filamentous parasites in the membrane removed from teeth. Ficinus (1847) observed filamentous organisms ( denticolae ) in the enamel cuticle (surface protein membrane of teeth) and in carious lesions.

26. Chemoparasitic theory States that caries is caused by acids produced by microorganisms of the mouth W.D. Miller (1890) carried out experiments which helped to establish this concept on a firm basis Emil Magitot (1867) demonstrated that fermentation of sugars caused dissolution of tooth material in vitro

27. Chemoparasitic theory Leber and Rottenstein (1867) presented additional experimental evidence implicating acids and bacteria as the causative agents of caries Described a specific microorganism, Leptothrix buccalis , in tubules of carious dentin and thought that it was responsible for enlarging the tubules and facilitating the rapid penetration of acids

28. Chemoparasitic theory Willoughby D. Miller’s facts on dental caries:- Acid was present within the deeper carious lesion, as shown by the litmus paper reaction Different kinds of foods mixed with saliva and incubated at 37 degree celcius could decalcify the entire crown of a tooth Several types of bacteria could produce enough acid to cause dental caries Lactic acid was an identifiable product in carbohydrate-saliva incubation mixtures Different micro-organisms invade carious dentin

29. Chemoparasitic theory Miller concluded that no single species of microorganisms caused caries but rather that the process was mediated by an oral micro-organism capable of producing acid and digesting protein. Dental decay is a chemo-parasitic process consisting of two stages- decalcification or softening of the tissues and dissolution of the softened residue. Incase of enamel, however the second stage is practically wanting, the decalcification of enamel signifying its total destruction

30. Evaluation of the Chemoparasitic theory There is no doubt that acids are involved in formation of caries Within carious lesions and in plaque, pH decreases following a rinse with a suitable substrate for bacterial fermentation Stephen (1940) showed that within 2-4 minutes of rinsing with glucose or sucrose solution the oH fell from about 6.5 to 5 and returned to the original pH within 40 minutes.

31. Evaluation of the Chemoparasitic theory The amount and duration of the drop in pH are influenced by The amount of interdental plaque The predominant flora The rate of salivary flow The type and concentration of substrate The location of plaque

32. Evaluation of the Chemoparasitic theory A variety of organic acids have been identified by specific chromatographic techniques in (dental plaque, bacterial cultures isolated from plaque and in carious lesions.) The relative concentrations of these acids may vary. Because plaque harbours a mixed bacterial population of homo and heterolytic fermentative microorganisms which differ in their fermentative capabilities

33. Significance of this theory He assigned an essential role to 3 factors in carious process- The oral microorganisms in acid production and in proteolysis. The carbohydrate substrate which microorganisms fermented The acid which causes dissolution of tooth minerals

34. Limitations of this theory It was unable to explain the predilection of specific sites on a tooth to dental caries. The initiation of caries on smooth surfaces was not accounted for by this theory. The concept of dental plaque adhering to the teeth and serving to localize bacterial enzymatic activity was not proposed until 1897 by Williams and 1898 by Black.

35. Proteolytic theory Gottlieb (1947)- Acid alone produces chalky enamel but not true caries Frisbie (1944)- Described caries as a proteolytic process involving depolymerization and liquefaction of the organic matrix of enamel Pincus (1949)- Contented that proteolytic organisms first attacked the protein elements, such as the dental cuticle, and then destroyed the prism sheaths. The loosened prisms would then fall out mechanically.

36. Limitations of the theory To date, nobody has under physiological conditions, successfully demonstrated loss of enamel tissue through proteolytic activity. Enamel is a highly structured tissue and the accessibility of organic material to enzymatic action before decalcification is restricted. Enamel can be dissolved under physiological conditions only by demineralization with acids, chelating or complexing agents.

37. Proteolytic chelation theory Chelation has been proposed as an explanation for tooth decay whereby the inorganic components of enamel can be removed at neutral or alkaline pH. These breakdown products have chelating properties and thereby dissolve the minerals in enamel Considers dental caries to be a bacterial destruction of teeth where the initial attack is essentially on organic components of enamel

38. Proteolytic chelation theory Decalcification is mediated by a variety of complexing agents such as, anions, amines, amino acids, peptides, polyphosphates and carbohydrate derivatives. These substances are either the breakdown of microbial products of enamel or dentin or of food that is ingested and diffuses through the plaque.

39. Limitations of the theory Less than one percent of mature enamel is organic in nature and the suggestion that this material upon degradation can give rise to a significant concentration of chelator sufficient to dissolve upto 96% mineral matter has no experimental support. While proteolysis chelation is an important biological phenomenon, its primary role in the etiology of the dental caries has not been corroborated.

40. Sulfatase theory Pincus (1950) the bacterial sulfatase hydrolyzes the mucoitinsulfate of the enamel and the chondroitin sulfate of the dentin producing sulphuric acid that, in turn, causes decalcification of dental tissues. Limitations of the theory The concentration of sulfated polysaccharides in enamel is very small and not readily accessible as a substrate for enzymatic degradation. This is a highly unlikely hypothesis for the degradation of tooth enamel.

41. Complexing and phosphorylation theory Uptake of phosphate by plaque bacteria occurs during aerobic and anaerobic glycolysis and the synthesis of polyphosphates. The high bacterial utilization of phosphate in plaque causes a local disturbance in the phosphate equilibrium in the plaque and the tooth enamel resulting in loss of inorganic phosphate from enamel. Soluble calcium- complexing compounds produced by bacteria cause further tooth disintegration.

42. Limitations of this theory Saliva is an abundant source of inorganic phosphate for bacterial utilization. Hence it is less likely that depletion of phosphate in plaque by oral microbial metabolism results in phosphate withdrawal from enamel

43. Etiology of dental caries Dental caries is a multifactorial disease in which there is interplay of 3 principal factors: (Keys 1960) The host (primarily saliva and the tooth) The dental plaque The substrate or diet

44. Newburn (1982) - fourth factor i.e Time must be considered in any discussion of the etiology of dental caries. Diagramatically these factors can be portrayed as four overlapping circles .

45. Conversely caries prevention is based upon: Increasing the resistance of host Lower the number of micro organisms in contact with the tooth. Modify the substrate by selecting non cariogenic foodstuffs. Reduce the time the substrate is in the mouth by limiting the frequency of intake.

46. Host factors: Tooth Tooth morphology and arch form A susceptible host is one of the factors required for caries to occur. Long been recognized as an important determinant of dental caries. On the basis of clinical observations, it is known that pits and fissures of posterior teeth are highly susceptible to caries. Investigations have shown a relationship between caries susceptibility and the depth of fissure

47. Certain surfaces of tooth are more prone to decay whereas other surfaces rarely show decay. The differences in the decay rates of various surfaces on the same tooth are in part due to morphology, irregularities in the arch form, crowding. The most susceptible permanent teeth are the mandibular first molars followed by maxillary first molars and mandibular and maxillary second molars. The second premolars, maxillary incisors and first premolars are next in sequence whereas the mandibular incisors are least likely to develop lesions

48. Tooth composition There is good evidence that the enamel surface is more resistant than the subsurface. Initial carious lesions reveal demineralization of subsurface enamel beneath the outermost layer that is only slightly affected. Moreno, E.C and Zahradnik , R.T 1974. Chemistry of enamel subsurface demineralization in vitro. J Dent Res 53:226-235

49. Host factors: Saliva

50. Host factors: Saliva Xerostomia- Dry Mouth (Bartley 1868) Causes include:- Sjogrens Syndrome, Diabetes Mellitus, Anxiety, surgical removal of salivary glands Caries in case of Xerostomia- 1) Decay in the cervical area, involves cementum, dentin and progresses inwardly until the crown is amputated

51. The management of dental caries in patients with xerostomia include the following: Host factors: Saliva

52. Concept of critical pH The pH at which any particular saliva ceases to be saturated with calcium and phosphate is referred to as “critical pH”. The inorganic material of the tooth may dissolve at this pH It is usually about 5.5.

53. Microflora Evidence of bacterial role in caries etiology The evidence for the role of micro organisms in dental caries is as follows: Germ free animals do not develop caries. Antibiotics fed to animals are effective in reducing the incidence and severity of caries. Totally unerupted and unexposed teeth do not develop caries, yet when exposed to the oral environment and microflora can become carious. Oral bacteria can demineralize enamel and dentin in vitro and produce caries like lesions Micro organisms have been histologically demonstrated invading carious enamel and dentin.

54. Localization of oral flora related to caries

55. Substrate: Diet and caries Dental caries is a dynamic process that involves susceptible tooth surfaces, cariogenic bacteria, mainly Streptococcus mutans, and a fermentable carbohydrate source. Sucrose is the most common dietary sugar and is considered the most cariogenic carbohydrate

56. Time Time is important in caries in relation to frequency and amount of exposure of the offending liquid, such excessive exposure should influence both the initiation and progression of lesions. Time is also important in relation to the duration of the deleterious habit. Duration should affect both the severity of lesion and number of teeth involved.

57. Winter et al (1971) reported that children with nursing caries had maintained their habit for a mean period of 18 months compared to a caries-free group in which the mean period was 14.2 months. A 4-month difference may not seem large until it is realized that since the maxillary incisors erupt at approximately 10 months of age, this difference doubles the time of cariogenic challenge.

58. Dental caries Presented by: Dr.Atharva Babel Dr. Babel’s Unique Dental Clinic, Pimple Saudagar

59. Contents Pathogenesis of dental caries Clinical characteristics of carious lesions Diagnosis of dental caries Conclusion References

60. Pathogenesis Of Caries At birth Shortly after birth Eruption of teeth Oral cavity lacks bacterial colonization Bacteria are continually introduced in mouth (animate & inanimate ). Successful colonization. STREPTOCOCCUS HAEMOPHILLUS NEISSERIA Non shedding surfaces allows colonization . STREPTOCOCCI ( Sanguis & mutans ) ACTINOMYCES Infectious Complications of Dental and Periodontal Diseases in the Elderly Population- Thomas T. Yoshikawa, AGING AND INFECTIOUS DISEASES • CID 2002:34 (1 May) • 1215 60

61. Carious lesion occurs only under a mass of bacteria capable of producing a sufficiently acidic environment to demineralize the tooth structure A gelatinous mass of bacteria adhering to tooth surface is “DENTAL PLAQUE” The Microbial Ecology of Dental Caries. - G. H. W. Bowden.Microbial Ecology in Health and Disease 2000; 12: 138–148 61

62. Stages In Development Of Dental Plaque Dental Plaque as a Microbial Biofilm P.D. Marsh, Caries Res 2004;38:204–211 62

63. Dental Plaque as a Microbial Biofilm P.D. Marsh, Caries Res 2004;38:204–211 63

64. DEMINERALIZATION OF TOOTH STRUCTURE Solubility properties of human tooth mineral and pathogenesis of dental caries. T Aoba. Department of Pathology, The Nippon Dental University, Tokyo, Japan Oral Diseases (2004) 10, 249–257 64 GIVEN ENOUGH TIME

65. At pH below 5.5 = tooth demineralization occurs At pH 3 – 4 = enamel is etched & roughened At pH 5 = surface remains intact + sub – surface mineral is lost INCIPIENT CARIES / WHITE SPOT LESION Solubility properties of human tooth mineral and pathogenesis of dental caries. T Aoba. Department of Pathology, The Nippon Dental University, Tokyo, Japan Oral Diseases (2004) 10, 249–257 65

66. After eruption  teeth are colonized by oral bacteria -create conditions that, in combination with saliva, modify the composition of teeth surfaces, making them more resistant to dental caries(post-eruptive enamel maturation) It is critically important for the caries process because it occurs in the tooth area with direct contact with the oral environment, where lesions start to develop. 66

67. What Constitutes Dental Caries? Histopathology of Carious Enamel and Dentin Related to the Action of Cariogenic Biofilms . E.A.M. Kidd* and O. Fejerskov . Royal DentalCollege , Faculty of Health Sciences, University of Aarhus,Vennelyst Boulevard,, Denmark J Dent Res 83(Spec Iss C):C35-C38, 2004 67

68. Occlusal caries:pathology,diagnosis and local magement . K.R Erkstrand,D.N.J Ricketts. Dent Update 2001;28:380-387 68

69. Strategies for Noninvasive Demineralized Tissue Repair. Mathilde C. Peters (DMD, PhD): Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of MichiganDent Clin N Am 54 (2010) 507–525 69 Non cavitated enamel lesions retain most of the original crystalline frame work -serves as nucleating agent for remineralization . Saliva supersaturated with Ca and PO 4 ions provides a driving force for remineralization to occur + F Remineralization with FLUORAPATITE  resistance to further caries attack. Remineralized lesion which is brown / discolored spot (trapped organic debris and metallic ions )

70. The Continuum of Dental Caries—Evidence for a Dynamic Disease Process. J.D.B. Featherstone. Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California at San Francisco, J Dent Res 83(Spec Iss C) 2004 CAVITATION :- occurs when a series of de-mineralization & re mineralization episodes are dominated by de – mineralization Sub – surface demineralization is so extensive that tooth structure loses support & collapses. 70

71. HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas . Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 HISTOPATHOLOGY OF ENAMEL CARIES 71

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73. SIEVE LIKE BEHAVIOUR OF ENAMEL Enamel rod boundaries provide sufficient porosity for movement of hydrogen ions (organic acid ) This movement of ions can explain acid dissolution of underlying dentine before actual cavitation of enamel surface Molecular sieve behaviour  of normal and carious human dental enamel. A.I. Darling, K.V. Mortimer, D.F.G. Poole, Dental School, University of Bristol, England. Archives of Oral Biology. Volume 5, Issues 3–4, Dec. 1961, Pages 251–272, 73

74. HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB. The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 74

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76. . Pit And Fissure caries Begins beneath plaque, decalcification Enamel thin at bottom, hence early dentin involvement occurs frequently Caries follows the direction of rods. 76

77. TRIANGULAR ; apex : Tooth surface; base: DEJ. DEJ: ↑no. of dentinal tubules are involved. ↑Cavitation than smooth surface caries ↑Undermining of enamel 77

78. Smooth surface Caries Begins beneath plaque, decalcification Triangular or cone shaped with apex: DEJ; base: tooth surface Finally there’s loss of enamel structure which gets roughened due to demineralization & disintegration of enamel prisms. 78

79. Before complete disintegration of enamel, several zones appreciated starting from advancing end of lesion. zones should not be interpreted as distinct entities but represent a continuum of changes in caries process. 79

80. Ultrastructural changes in the translucent and dark zones of early enamel caries. H. J. ORAMS, P. P. PHAKEYt , W. A. RACHINGERt , J. J .Department of dental medicine and surgery, university of melbourne , parkville , victoria , Journal of Oral Pathology 1980:9: 54-61 80

81. HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 ZONE 1 : TRANSLUCENT ZONE Present at the advancing front of enamel lesion Deepest zone Structureless appearance when perfused with quinoline solution & examined with polarized light pore volume - 1% . There is less demineralization. 81

82. ZONE 2 : DARK ZONE HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 Does not transmit polarized light It is termed as positive zone because it is mostly present. P resent due to remineralization of enamel. Pore volume – 2% to 4%. Designated as dark zone as it does not transmit polarized light due to Prescence of many tiny pores too small to absorb quinoline These tiny pores formed by deposition of ions in to large pores 82

83. ZONE 3 : BODY OF THE LESION Lies in between dark zone & surface layer. Under light – the ground sections revealed: Well marked striae of retzius Cross striations in enamel prisms Pore volume of 5% at periphery and 25% at center of lesion Area of greatest demineralization . 83 HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7

84. ZONE 4 : SURFACE ZONE most superficial zone. most unaffected zone due to resistance of surface zone to decalcification. Greater degree of mineralization of surface ( hypermineralized surface). Increased concentration of fluoride in surface enamel Pore volume is less than 5%. HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 84 HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7

85. Spread of caries is more in dentin compared to enamel  Decreased calcification Existence of pathways (dentinal tubules) Once the enamel caries reaches the DEJ it spreads ,with the rapid involvement of a great number of dentinal tubules. Each dentinal tubules acts as a tract along which microorganisms travel to the pulp. 85

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88. Three levels of dentinal reaction to dental caries can be recognized 1. Reaction to low level acid dimeneralization - slow advancing lesion 2. Reaction to moderate intensity attack 3. Reaction to rapidly advancing caries( high acid level) Fejerskov O,Kidd EAM.Dental caries:The disease and its clinical management .2 ND EDITION.Oxford:Blackwell;2008. 88

89. 1. In slow advancing caries Vital pulp can repair demineralized dentine by remineralization of intertubular dentine & apposition of peritubular dentine Crystalline precipitates formed in lumen of dentinal tubules in advancing front of demineralization zone Tubules completely occluded + mineral loss in intertubular dentine 89

90. 2. Response to moderate intensity irritants Results in bacterial invasion of dentine Infected dentine contains – bacteria , bacterial cellular debris, high acid levels & hydrolytic enzymes  degeneration & death of odontoblasts & their tubular extension + mild inflammation of pulp Pulp may be irritated to cause  formation of replacement odontoblasts  REPARATIVE DENTINE  forms an effective barrier to diffusion of materials through tubules. 90

91. 3. Response to severe irritation Acute rapidly advancing caries with high level of acid production overpowers dentinal defences  Infection, abscess & death of pulp. Pulp dentine complex reacts to caries attack by initiating remineralization & blocking off open tubules Small localized infection in pulp produces an inflammatory response involving capillary dilatation, local edema & stagnation of blood flow, local anoxia & necrosis. Fejerskov O,Kidd EAM.Dental caries:The disease and its clinical management .2 ND EDITION.Oxford:Blackwell;2008.p 4-6. 91

92. Five zones in carious dentine 92

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96. Conventional caries diagnostic methods Visual examination Illumination Visual and Tactile examination Radiographic examination Caries Detecting Dyes 96

97. Conventional caries diagnostic methods Detecting caries is by visual inspection of dental surfaces with the aid of a bright light and dental mirror. Visual examination

98. Most commonly used method for detecting caries lesions Includes looking for cavitation, surface roughness, opacification and discoloration. Conventional caries diagnostic methods C E Ketley & R D Holt in 1993 compared the visual and radiographic diagnosis of occlusal caries in first permanent molars and in second primary molars and found that visual examination alone is not a reliable method for detection for dental caries.

99. Magnification Visual examination without aids – unreliable Magnifying dental mirrors Magnification loupes - Head worn prism loupes (X 4.5) - Surgical microscopes(X 16) may be used Provide better comfort and accuracy Conventional caries diagnostic methods

100. Illumination LED light attachments to the dental chair also enhance the brightness and thus increase the contrast to detect the lesions 100 Conventional caries diagnostic methods

101. Visual and tactile examination B ased primarily on subjective interpretation of surface characteristics such as integrity, texture, translucency/opacity, location and color . B ased on the use of a dental mirror, a sharp probe and an air syringe and requires good lighting and a clean/dry tooth surface . 101 Conventional caries diagnostic methods

102. Visual and tactile examination- Limitations Sharp tips physically damage small lesions with intact surfaces Probing can cause fracture & cavitation of incipient lesion Mechanical binding may be due to non-carious reasons 102 Conventional caries diagnostic methods

103. Radiographic examination Carious lesions are detectable radiographically when there has been enough demineralization to allow it to be differentiate from normal They are valuable in detecting proximal caries which may go undetected during clinical examination. Atleast 40-45% demineralization is required for definitive decision on caries 103 Conventional caries diagnostic methods

104. Radiographic examination- Limitations A certain amount of mineral must be lost before it can be detected in a radiograph A shallow, widespread lesion may create an image of being deeper than a deep lesion that is narrowly spread on the surface. Besides concerns about low-dose radiation and variations in how images are interpreted by dentists, the main limitation is that the validity in diagnosing early lesions is rather low.  104 Conventional caries diagnostic methods

105. Caries Detecting Dyes Dyes are a diagnostic aid for detecting caries in questionable areas. They selectively complex with carious tooth structure which is later disclosed with the help of fluorescence Aid in both quantitative & qualitative analysis of the lesion 105 Conventional caries diagnostic methods

106. Caries Detecting Dyes- Disadvantages Dye staining and bacterial penetration are independent phenomena, hence no actual quantification They also stain food debris, enamel pellicle, other organic matter Dye aided carious removal-strenuous Stains DEJ 106 Conventional caries diagnostic methods

107. Advanced caries diagnostic methods Subtraction Radiography Fibre Optic Transillumination( foti ) Digital Imaging Fibre -optic Transillumination ( Difoti ) Quantitative Light Induced Fluorescence ( Qlf ) 107

108. Laser Fluorescence device ( DIAGNOdent ) Electrical conductance method (ECM) ENDOSCOPIC FILTERED FLUORESCENCE (EFF) MIDWEST CARIES-ID 108 Advanced caries diagnostic methods

109. Cariescan Infrared Fluorescence Photothermal Radiometry (PTR) Terahertz Pulse Imaging Advanced caries diagnostic methods

110. Multiphoton Imaging Optical Coherence Tomography (OCT) Cone Beam Computed Tomography ( Cbct ) Ultrasound Imaging 110 Advanced caries diagnostic methods

111. Intraoral Camera Magnetic Resonance Imaging(MRI) Monoclonal Antibodies D-caries Mini Advanced caries diagnostic methods

112. Subtraction radiology Radiographic subtraction has been extensively evaluated for both the detection of caries and also the assessment of bone loss in periodontal studies. The basic premise of subtraction radiology is that two radiographs of the same object can be compared using their pixel values. The value of the pixels from the first object are subtracted from the second image. Advanced caries diagnostic methods

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114. Fiber -Optic Transillumination (FOTI) Developed by Friedman and Marcus in 1970 for detection of proximal lesions. carious enamel has a lower index of light transmission than sound enamel. Advanced caries diagnostic methods

115. Advanced caries diagnostic methods Vaarkamp et al (2000) compared the conventional bitewing radiography with FOTI in detecting proximal carious lesions. FOTI was found to be more sensitive diagnostic technique as compared to Bitewing radiography Vaarkamp J, ten Bosch JJ, Verdonschot EH, Bronkhoorst EM.The real performance of bitewing radiography and fiber-optic transillumination in approximal caries diagnosis. J Dent Res. 2000 Oct;79(10):1747-51.

116. This method of caries detection uses a light source, preferably bright to illuminate the tooth. This effect can be achieved with a fiber optic illuminator, which is readily available at the handpiece coupler of the dental operatory. 116

117. Digital imaging fibre-optic transillumination (DIFOTI) D igitized and computed version of the FOTI. D igital imaging fibre-optic transillumination is used for detection of both incipient and frank caries in all tooth surfaces. Can also be used to detect fractures, cracks and secondary caries around restorations. Advanced caries diagnostic methods

118. Advanced caries diagnostic methods Schneiderman A. et al in 1997 compared DIFOTI with visual inspection in diagnosing occlusal, proximal and smooth surface lesions. Results showed that DIFOTI was a MORE SENSITIVE method in detecting carious lesions. Young et al in 2005 performed a study comparing DIFOTI with F speed radiographic film in determining the depth of proximal lesions and concluded that DIFOTI was not a reliable method for the depth determination of proximal lesions . F speed films were superior in measuring the depth of carious lesion.

119. Quantitative Light-induced Fluorescence (QLF) based on auto-fluorescence of teeth. When the teeth are illuminated with high intensity blue light, the auto-fluorescence of enamel is detected by an intraoral camera which produces a fluorescent image. The emitted fluorescence has a direct relationship with the mineral content of the enamel. Advanced caries diagnostic methods

120. QLF uses a blue light (488 nm) to illuminate the tooth, which normally fluorescence a green colour. Teeth should be dried before its application. 120

121. It cannot differentiate between decay and hypoplasia Has inability to detect or monitor interproximal lesions Limited measurement of enamel lesions depth. 121 Disadvantages

122. Laser fluorescence - DIAGNODent The DIAGNODent (DD) instrument ( KaVo , Germany 1999) is another device employing fluorescence to detect the presence of caries. 122 Advanced caries diagnostic methods

123. 123 Using a small laser the system produces an excitation wavelength of 655 nm which produces a red light. This is carried to one of two intra-oral tips; one designed for pits and fissures, and the other for smooth surfaces. The tip both emits the excitation light and collects the resultant fluorescence.

124. Displays a numerical value on two LED displays. The first display tells the current reading while the second display tells the peak reading for that examination. 124 Several factors that can alter the readings- Drying time of the site before the assessment, presence of plaque or pigmentation and presence of prophylaxis paste It should be used as an adjunct to visual inspection, and an alternative for radiography. Chun Hung Chua,Alex M. H. Chaub,Edward C. M. Lo. Current and Future Research in Diagnostic Criteria and Evaluation of Caries Detection Methods. Oral Health Prev Dent 2013;11:181-189

125. DIAGNODent pen Works on the same principles but the design is different. The tip is rotatable around the axis of its length, enabling the operator to assess mesial and distal surfaces from both sides (buccal and lingual). 125 Advanced caries diagnostic methods

126. After excitation, the tip collects the fluorescence and translates it into a numerical scale from 0 to 99. This device could be used as an alternative to the radiographic method to aid the dentist in the decision-making process after visual inspection. 126 Readings Relevance 0-13 No Caries 14-20 Enamel Caries 21-30 Dentinal Caries 30+ Operative Care Advised

127. Electrical Conductance Method ( Ecm ) E mploys a single, fixed-frequency alternating current which attempts to measure the ‘bulk resistance’ of tooth tissue. This can be undertaken at either a site or surface level. 127 Advanced caries diagnostic methods Factors that affect ECM results - the temperature of the tooth - the thickness of the tissue - the hydration of the material - the surface area.

128. Midwest Caries I.D Detects differences of optical behaviour inside the tooth related to change in the tooth structure and it is therefore not sensitive to bacterial content. It uses infrared and red light emitting diodes and a fibre optic to distribute light to the observed area present at the probe tip. 128 Advanced caries diagnostic methods

129. A second fibre optic collects light from the observed area to a photodetector that measures returned collected light. This photodetector then transmits the signal to a microprocessor that compares signal levels with defined parameters. When the result is positive, the processor deactivates the third green LED and pulses at a higher intensity than the red LED. 129

130. T his device can give false positive signals in cases of teeth with - teeth with thick, dark stains - hyper mineralization - hypocalcification , dental fluorosis, and atypically shaped teeth due to alteration in the translucency of enamel caused by these conditions. 130

131. CarieScan PRO uses spectroscopy to quantify dental caries early enough to enhance preventive treatment. Indicated for the detection, diagnosis and monitoring of dental caries on occlusal and accessible smooth surfaces, which are not clearly visible to the human eye. Involves the passage of electrical current through the tooth to identify the presence and location of the decay. 131 Advanced caries diagnostic methods

132. During measurement - green color = sound tooth tissue red color = deep caries requiring operative therapy yellow color with a range of numerical figures from 1 to 99 = varying severity caries which require only preventive care. 132

133. Infrared fluorescence The tooth is exposed to light radiation with a wavelength of 700-15,000 nm. Barrier filters are used to observe any resulting fluorescence. A. Hall,J.M . Girkin . A Review of Potential New Diagnostic Modalities for Caries Lesions J Dent Res 83(Spec Iss C):C89-C94, 2004 133 Advanced caries diagnostic methods

134. Heating effects from absorption of infrared radiation may have potentially damaging effects on the dental pulp, given the increased penetration and decreased scattering of the longer wavelength. A. Hall,J.M . Girkin . A Review of Potential New Diagnostic Modalities for Caries Lesions J Dent Res 83(Spec Iss C):C89-C94, 2004 134

135. Terahertz Pulse Imaging Uses waves with tetrahertz frequency(=1012Hz or a wavelength of approximately 30μm) for an image to be obtained by tetrahertz irradiation It is possible to record tetrahertz images using CCD detector. A. Hall,J.M . Girkin . A Review of Potential New Diagnostic Modalities for Caries Lesions J Dent Res 83(Spec Iss C):C89-C94, 2004 135 Advanced caries diagnostic methods

136. It has- no adverse thermal effects non ionising radiation low signal to noise ratio Dental applications limited and the cost of equipment is high and careful interpretation is required. Longitudinal sections through permanent molars have demonstrated increased terahertz absorption by early occlusal caries and an ability to discriminate dental caries from enamel hypomineralisation . 136 A. Hall,J.M . Girkin . A Review of Potential New Diagnostic Modalities for Caries Lesions J Dent Res 83(Spec Iss C):C89-C94, 2004

137. Multiphoton Imaging Infra red light of 850 nm has been used for multiphoton imaging of teeth. In the multiphoton technique two infrared photons (with half the energy of blue photon) are absorbed simultaneously. 137 Advanced caries diagnostic methods

138. With this technique, sound tooth tissue fluoresces strongly, whereas carious tooth tissue fluoresces to a much lesser extent. Able to record the sectional images from the tooth to form a 3D image. Caries will appear as a dark form with in a brightly fluorescing tooth. 138

139. Optical Coherence Tomography (Oct) Introduced by Baumgartner et al, 2000 Based upon the interference of light when a light beam is split into two and then recombined, interference produces a pattern Works in wavelengths of 840-1310nm resulting in imaging depths of 0.6 to 2-0 mm. 139 Advanced caries diagnostic methods

140. Taking several scans along a line produces information from a 'slice' of tooth tissue which is the tomogram. Carious tissue scatters light to a greater extent than sound tooth structure. 140

141. Cone beam computed tomography (CBCT) Radiographic technique designed to image a slice or series of images at different levels 141 Advanced caries diagnostic methods

142. CBCT utilizes the least amount of radiation to obtain an accurate diagnostic image. 142 Zhi -ling Zhang et al in 2011 performed a study to compare the CBCT imaging with radiographic film and phosphor plates for detection of proximal caries. They found that CBCT performed better as compared to other two diagnostic aids. Zhi -ling Zhang, Xing-min Qu, Gang Li, Zu-yan Zhang, Xu- chen Ma. The detection accuracies for proximal caries by cone beam tomography, film and phosphor plates. Oral surg oral med oral path oral radio 2011;111:103-108.

143. Ultrasound imaging Proposed by Bab et al.(1997) U se ultrasound waves which travel along the interface between enamel and air to detect surface discontinuity from cavitated proximal lesions. 143 The principle behind the technique is that sound waves can pass through gases, liquids and solids and the boundaries between them. Images of tissues can be acquired by collecting the reflected sound waves. Advanced caries diagnostic methods

144. Using a flexible probe tip which fit into wedge shaped interproximal contours, the method was able to show stronger ultrasound reflections from cavitated lesions compared to non- cavitated lesions. 144 A later study by the same group of researchers in 1998 involving 253 caries sites showed that their Ultrasonic Caries Detector (UCD) could distinguish between interproximal caries from an intact site, using bitewing radiography as a standard.

145. Advanced caries diagnostic methods Intraoral Camera 145 Magnified oral conditions significantly improve visual examination Patient education Forgie et al (2003) reported significantly high level of sensitivity with its use

146. Advanced caries diagnostic methods Magnetic Resonance Imaging (MRI) Uses the magnetic properties of atomic nuclei(proton) present in water molecules Difficult to distinguish the hard tissues of the tooth within MRI scans due to their scarce water content. 146

147. Advanced caries diagnostic methods Idiyatullin Din 2011studied the diagnostic ability of MRI system. They found that MRI was not only able to detect the carious lesion but also the extent of the lesion was made visible. Another in vitro study by Bracher et all in 2013 showed an accuracy rate of 97% as compared to conventional radiographic methods which showed an accuracy rate of 85%.

148. Monoclonal Antibodies 148 Shi et al (1998) identified specific monoclonal antibodies that recognise the surface of cariogenic bacteria The probes are tagged with fluorescent molecules that measure quantitatively with spectrometer Can be used chairside by the dentist and provide instant results Advanced caries diagnostic methods

149. D-caries Mini Portable device based on fibreoptic principle has been developed by Necks Technologies (Canada) Easy to use and requires no calibration Works on the principal of difference in optical behaviour inside the tooth related to change in the tooth structure. Bennett T. Amaechi.Emerging technologies for diagnosis of dental caries: The road so far. J. Appl. Phys. 2009;105:02047(1)-102047(9). 149 Advanced caries diagnostic methods

150. Uses infrared and red light emitting diodes(LEDs) and a fibre optic to distribute light to the observed area present at the probe tip. A second fibre optic collects light from the observed area to a photodetector that measures returned collected light. This photo detector then transmits the signal to a microprocessor that compares signal levels with defined parameters. Sterilizable , non-invasive device designed to detect both occlusal and interproximal caries, using the same two-in-one cordless battery operated probe and a compact profile that offers practitioners easy handling 150

151. References Bennett T. Amaechi.Emerging technologies for diagnosis of dental caries: The road so far. J. Appl. Phys. 2009;105:02047(1)-102047(9). Zhi -ling Zhang, Xing-min Qu, Gang Li, Zu-yan Zhang, Xu- chen Ma. The detection accuracies for proximal caries by cone beam tomography, film and phosphor plates. Oral surg oral med oral path oral radio 2011;111:103-108. Occlusal caries:pathology,diagnosis and local magement . K.R Erkstrand,D.N.J Ricketts. Dent Update 2001;28:380-387

152. References A. Hall,J.M . Girkin . A Review of Potential New Diagnostic Modalities for Caries Lesions J Dent Res 83(Spec Iss C):C89-C94, 2004 Chun Hung Chua,Alex M. H. Chaub,Edward C. M. Lo. Current and Future Research in Diagnostic Criteria and Evaluation of Caries Detection Methods. Oral Health Prev Dent 2013;11:181-189 Vaarkamp J, ten Bosch JJ, Verdonschot EH, Bronkhoorst EM.The real performance of bitewing radiography and fiber -optic transillumination in approximal caries diagnosis. J Dent Res. 2000 Oct;79(10):1747-51. Fejerskov O,Kidd EAM.Dental caries:The disease and its clinical management .2ND EDITION.Oxford:Blackwell;2008.p 4-6. HISTOPATHOLOGY OF ENAMEL CARIES. B. GOTTLIEB

153. References The Research Department of Bayler University, College of Dentistry, Dallas,Texas Journal of Dental Research; Oct1944, Vol. 23 Issue 5, p379-384, 6p, 7 The Continuum of Dental Caries—Evidence for a Dynamic Disease Process. J.D.B. Featherstone. Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California at San Francisco, J Dent Res 83(Spec Iss C) 2004 Strategies for Noninvasive Demineralized Tissue Repair. Mathilde C. Peters (DMD, PhD): Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of MichiganDent Clin N Am 54 (2010) 507–525 What Constitutes Dental Caries? Histopathology of Carious Enamel and Dentin Related to the Action of Cariogenic Biofilms. E.A.M. Kidd* and O. Fejerskov . Royal DentalCollege , Faculty of Health Sciences, University of Aarhus,Vennelyst Boulevard,, Denmark J Dent Res 83(Spec Iss C):C35-C38, 2004 Solubility properties of human tooth mineral and pathogenesis of dental caries. T Aoba. Department of Pathology, The Nippon Dental University, Tokyo, Japan Oral Diseases (2004) 10, 249–257 The Microbial Ecology of Dental Caries. - G. H. W. Bowden.Microbial Ecology in Health and Disease 2000; 12: 138–148 Infectious Complications of Dental and Periodontal Diseases in the Elderly Population- Thomas T. Yoshikawa, AGING AND INFECTIOUS DISEASES • CID 2002:34 (1 May) • 1215