smile design

principles and practice of esthetic dentistry

1. SMILE DESIGN

2. CONTENTS: Introduction Definitions and classification Esthetic diagnosis and treatment planning Esthetic sequencing Perceptual aspects – the art of illusion Process of smile design and analysis Esthetic contouring Esthetics with composites   Esthetics with ceramics  Conclusion   2

3. INTRODUCTION: Smile—the perceiveness of one’s personality is said to be a God’s gift. Certain issues might create discrepancies in this appearance, the role of a cosmetic dentist is crucial in analyzing and crafting the desired smile.  Scottish physiologist Charles bell (1774-1842) was quoted as remarking that the thought is to the word that the feeling is to the facial expression. The focus of dentistry in the present times is not only the prevention and treatment of diseases but on meeting the demands for better esthetics. Esthetic dentistry is emerging as one of the most progressive and challenging branches of this field. Basically the smile is dependent on the musculature and the presence of the teeth. But every person is not fortunate enough to have a beautiful smile. The answer to the above problem is the esthetic dentistry which has developed leaps and bounds with the latest technologies and materials. 3

4. Esthetic dentistry is characterized primarily by the smile. The goal in the creation of esthetic dental restorations is to stimulate, or improve upon, the appearance of the natural dentition. The successful esthetic restorations must integrate harmoniously with the whole of the face., not just with the surrounding teeth. Smile designing is not only related to restorative dentistry , in fact it is an interdisciplinary approach involving restorative, orthodontic, prosthodontic and periodontal aprroaches. 4

5. DEFINITIONS: Esthetics (adj. 1798)   The branch of philosophy dealing with beauty. In dentistry, the theory and philosophy that deal with beauty and beautiful, esp. with respect to the appearance of a dental restorations, as achieved through its form and or color. Those subjective and objective elements and principles underlying the beauty and attractiveness of an object, design or principle. Dental Esthetics   The application of the principles of esthetics to the natural or artificial teeth and restorations. (GPT 1999)  5

6. Esthetic Dentistry Can be defined as the art and science of dentistry applied to create or enhance beauty of an individual within functional and physiological limits. Cosmetic dentistry is application of the principles of esthetics and certain illusionary principles, performed to signify or enhance beauty of an individual to suit the role he has to play in his day-to-day life or otherwise. Smile designing Is a process whereby the complete oral hard and soft tissues are studied and evaluated and certain changes are brought about which will have a positive influence on the overall esthetics of the face. These changes are governed by the principles of esthetic dentistry 6

7. CLASSIFICATION OF SMILE: (Solomon) Depending on the nature of labial mucous membrane papilla smile Gingival smile Mucosa smile Dependant on the lip component Straight smile Convex smile Concave smile 7

8. ESTHETIC DIAGNOSIS & TREATMENT PLANNING: A meticulous esthetic diagnosis followed by a well- defined treatment plan is the foundation of successful esthetic dental treatment. The definitive treatment plan should address the treatment periods, expenses, treatment sequencing and all aspects related to the function and maintenance of the anticipated results. Patient history :- Information should cover aspects of -medical history- allergic, systematic disorders , pervious surgeries e.t.c Dental history- past dental experiences , apprehensions, expectations e.t.c Personal and social history 8

9. Clinical examination :- A clinical examination involves a through evaluation of facial and temporomandibular components and assessment of occlusal relationship, periodontal attachment, teeth and intra-oral soft tissues Facial components:- Face form Symmetry along the midline Relationships of various parts of the face Position of the lips and chin from frontal as well as lateral aspect Relationship of horizontal and vertical references of face with respect to teeth and gums TMJ :- Palpated and auscultated for clicking Crepitus Hypermobility Deviation 9

10. OCCLUSION RELATIONSHIPS:- Occlusal pattern Type Contacts PERIODONTAL ATTCHMENT:- Plaque Calculus Gingival inflammation Amount of attached gingiva Recession Hyperplasia of gingiva TEETH:- Caries Existing restoration Discoloration Wear facets 10

11. Phonetics:- S sound anterior speaking space posterior speaking space Adequate/deficient Adequate/deficient F or V sound Incisal edge of maxillary incisors Touches inner vermilion boarder Touches outer vermilion boarder of lower lip Does not touch lower lip M sound Incisal display <1mm 1-4mm >4mm 11

12. TOTAL SMILE ANALYSIS: Total smile analysis is a cumulative interference analysis, drawn by interpreting and integrating various analysis like a visual, space profile and computer analysis after performing the preliminary analysis. 12

13. SPACE ANALYSIS: help to gauge the amount of space available during the treatment planning stage(measure the widths of all teeth and to compare it with the space present in the arch). Disproportionate space may be due to discrepancies in jaw and tooth size, malformed teeth, missing teeth, malaligned teeth, etc Corrections of labiolingual inclinations and rotations of teeth by restorative procedures will result in a change in the width space ratio due to the change of angulation involved. 13

14. PROFILE ANALYSIS:- straight orthognathic – normal profile. Any deviation from this should be recorded and considered in treatment planning. Examination of the profile could be in the antero-posterior plane or in the vertical plane. COMPUTER ANALYSIS:- Radiographic and photographic assessments can be used. Computer aided technology has broadened the utility of radiographs and photographs in the dental field. They give enlarged images of the photographic and radiographic outputs on the screen without the involvement of any hard copies of photographs or radiographs with multiple magnifications & at various angles. Esthetic enhancement with a change of arrangement , form , shape or color can be demonstrated quickly. 14

15. COMPONENTS OF AN ESTHETIC SMILE 15

16. 16

17. During a relaxed 'ideal smile', the upper lip exposes the cervical aspects of the maxillary anterior teeth. The gingival margins of the maxillary central incisors should be symmetrical and at the same height. Up to 3 mm of gingival exposure above the cervical margins of the maxillary teeth is aesthetically acceptable . Beyond 3 mm results in a 'gummy' smile, requiring correction by orthodontic or surgical intervention to avoid visual tension . 17

18. Treatment modalities depend on the type of pathosis , hyperplastic gingivae  gingivectomy or crown lengthening recession  orthodontics or cosmetic periodontal plastic surgery using tissue grafts or guided tissue regeneration membranes over eruption  orthodontic intrusion deficient pontic sites  ridge augmentation procedures skeletal abnormalities  orthognathic surgery. 18

19. E-line or esthetic line is an imaginary line connecting the tip of the nose to the most prominent portion of the chin on the profile, ideally the upper lip is 1-2 mm behind and the lower lip 2-3mm behind the E-line . Any change in the position of the E-line indicates the abnormality in the upper or lower lip position.   19

20. Vital Elements of Smile Design- Dental Components 20

21. MIDLINE : Dental midline should be collinear with facial midline. Vertical contact interface between the 2 centrals Perpendicular to the interpupillary line and parallel to facial midline As long as the midline is parallel with the long axis of the face , midline discrepancies up to 4mm is not considered unaesthetic. But canted midlines aren’t considered esthetic. Image of smile where the facial and dental midline do not line up. 21

22. A slanted mid line, or a dental mid line that is placed obliquely in relation to the facial mid line, will always distort the symmetry, even placed in exactly the correct position. It looks even more unpleasant when it is slanted and shifted to the side at the same time. 22

23. INCIAL LENGTHS( EDGE POSITION) : Most important determinant in smile creation as once set, it serves as a reference point for establishing the proper tooth contours and gingival levels. IMPORTANT PARAMETERS  Degree of tooth display Phonetics Patient input 23

24. The normal tooth display at rest is about 2.5 to 3mm. If the overall display of teeth is less than 2.5 mm then orthodontic extrusion or orthognathic surgery has to be considered. In teeth with both angles fractured, this can serve as a guide in deciding placement of incisal edge. But this is only true for young individuals. Degree of tooth display Image of the lower one third showing tooth display at rest. The display was measured to be between 2.5 to 3 mm. 24

25. PHONETIC REFERENCES : Phonetics play a part in determining maxillary central incisor design and position.  ‘F’ and ‘V’ sounds are used to determine the tilt of the incisal third of the maxillary central incisors and their length. ‘E’  incisal edge should be halfway between upper and lower lip 25

26. The ‘M’ sound is used to achieve relaxed rest position and repeated at slow intervals can help evaluate the incisal display at rest position . ‘S’ or ‘Z’ sounds determine the vertical dimension of speech. Its pronunciation makes the maxillary and the mandibular anterior teeth come in near contact and determine the anterior speaking space. 26

27. TOOTH DIMENSIONS Correct dental proportion is related to facial morphology and is essential in creating an esthetically pleasing smile. CENTRAL DOMINANCE dictates that the centrals must be the dominant teeth in the arch and they must display pleasing proportions. The proportions of the centrals must be esthetically and mathematically correct  the width to length ratio  4:5 The shape and appearance of th e centrals influences the placement of laterals and canines. 27

28. GUIDELINES FOR CORRECT PROPORTIONS… 28

29. Golden Proportion is expressed in numerical form and applied by classical mathematicians such as Euclid and Pythagoras in pursuit of universal divine harmony and balance. It has been applied to a lot of ancient Greek and Egyptian architecture and may be expressed as the ratio 1.618:1. If the ratio is applied to the smile made up of the central, lateral incisor and the mesial half of the canine, it shows that the central incisor is 62% wider than the lateral incisor which in turn is 62% wider than the visible portion of the canine which is the mesial half, when viewed from the front. 29

30. RECURRING ESTHETIC DENTAL PROPORTION (ward) The successive width proportions when viewed from the facial aspect should remain constant as we move posteriorly from midline. This offers greater flexibility to match the tooth proportions to the facial dimensions. M PROPORTION CHU’S ESTHETIC GAUGE  Computer software Image showing close to an 80% width to- length ratio and optical width of the central relative to the lateral and the lateral relative to the canine. Note that esthetic percentages do not follow the golden proportion, especially the canine. 30

31. INDIVIDUAL TOOTH DIMENSIONS… MAXILLARY CENTRAL INCISOR- focal point Length 10-11 mm Width 75-80% of length MAXILLARY LATERAL INCISOR- Playful part of smile Provide individuality Never symmetrical Influence gender characterization 31

32. MAXILLARY CANINES- Critical point in creating a pleasing smile Junction between the anterior and posterior teeth Supports frontal muscles Size and shape of buccal corridor depends on the canine Note :- Centrals wider than laterals by 2-3mm canines by 1-1.5mm Canine wider than lateral by 1- 1.5mm Canine and central are longer than lateral by 1-1.5mm MAXILLARY BICUSPIDS- Important role in arch design Fill the buccal corridor 32

33. BUCCAL CORRIDOR In an esthetic smile there is what has been termed negative space , which is a small space between the maxillary posterior teeth and the inside of the cheek. In an esthetic smile the percentage visibility decreases as we go more posteriorly . If there is any malocclusion or discrepancy in arch form leads to loss of esthetics. 33

34. If the space appears excessive when the patient is smiling, a small amount of the space can be filled by increasing the buccal contours of the maxillary posterior restorations. If conservative additive or subtractive (i.e., esthetic contouring) techniques will not work esthetically, then orthodontics should be considered. Gives depth & mystery to the smile Indicates occlusal disturbance or inadequate restorative dentistry 34

35. Interdental contact areas & points Longest contact – between central incisors Shortest contact- between lateral & canine Interdental contact points – where the interdental contact area ends 35

36. The contact points of the maxillary teeth are relevant for ensuring optimal 'pink aesthetics' for patients with a high smile line (or visible cervical margins). the '5 mm rule', states that when the distance from the contact point to the interproximal osseous crest is 5 mm or less, there is complete fill of the gingival embrasures with an interdental papilla. For every 1 mm above 5 mm, the chance of complete fill is progressively reduced by 50%. Black triangle 36

37. Interdental contact area can be moved apically to close the gap 37

38. GINGIVAL ZENITH OR HEIGHT OF CONTOUR: The apex of the gingival height of contour on the anterior teeth is called zenith point. Central : distal third Lateral: central Cuspid : distal third Bicuspids : central 38

39. Nicely scalloped gingival contours – the pleasing relationship of the zenith points should create a shallow reverse triangle at zenith point of lateral incisor – 0.5 – 1mm incisally . 39

40. INCISAL EMBRASURES In an esthetic smile, the edges of the maxillary anterior teeth follow a convex or gull-wing course matching the curvature of the lower lip. Reduced incisal embrasures and leveling of the gull-wing effect as in a straight smile line is associated with aging. 40

41. Smallest & sharpest between the central incisors 90º between premolars in young unworn dentitions In aged / worn dentition – embrasures are smaller or disappear – teeth need to be lengthened & embrasures need to be recreated 41

42. Sex, age and personality 42

43. Soft tissue component of smile The lips frame the teeth and gingiva. The gingiva frames the teeth. The ratio of tooth structure to the amount of gingival and labial tissue should be harmonized to prevent an over-dominance of any one element. Gingival Line : GAL- gingival aesthetic line – the ideal gingival line from the cuspid to the central incisors intersects the dental midline at an angle >45° but <90°. The key esthetic issue is that the gingival line for the anterior teeth should be relatively horizontal to the horizon and relatively symmetric on both sides of the midline. In an esthetic smile, the volume of the gingiva from the apical aspect of the free gingival margin to the tip of the papilla is about 40% to 50% of the length of the maxillary anterior tooth and fully fills the gingival embrasure. 43

44. 44

45. Image demonstrating the measurements of the ideal gingival scallop, with the percentages showing the papilla length relative to tooth length. Image showing the gingival line on the same patient. Note the lateral and central apical position of the gingival margin is on a straight line that is completely horizontal. 45

46. Periodontal biotype and bioform The human tissue biotype is classified as thin, normal or thick.  The thin periodontal biotypes are friable, escalating the risk of recession following crown preparation and periodontal or implant surgery. This is particularly significant for full coverage crowns for the following reasons. Firstly, the thin gingival margins allow visibility of a metal substructure (either porcelain fused to a metal crown or implant abutment), thereby compromising aesthetics in the anterior regions of the mouth. In these circumstances, all-ceramic crowns, or ceramic implant abutments are a prerequisite to avoid aesthetic reproval . Secondly, due to the fragility of the thin tissue, delicate management is essential for avoiding recession and hence visibility of subgingivally placed crown margins at the restoration/tooth interface. 46

47. ESTHETIC TREATMENT PLANNING AND SEQUENCING integral part of treatment planning Treatment procedure which will be programmed or charted FINAL CASE PRESENTATION:- three basic methods 1 . Mock up - with soft tooth colored wax or composite resin- Direct composite resin placement along with the use of intraoral markers ( provide a visual three dimensional means for the patient to see the final result prior to committing to treatment). The functional movements in the mouth can also be checked at this time to determine any occlusal obstruction or difficulties. 47

48. 2. Diagnostic wax-up or study casts- This wax up can be evaluated by the patient directly on the diagnostic casts of the articulator and also intraorally with the use of acrylic overlays and acetate matrices. 3. Computer imaging- Digital imaging takes advantage of contemporary technology. In a particular case, esthetic enhancement with a change of arrangement, form, shape and color can be demonstrated quickly. 48

49. COLOR: Colour cant be perceived without light (electromagnetic energy). visible light spectrum of light - 380nm to 760nm. ability to stimulate the cells in the retina which is interpreted by the brain, discerning the sense of colour. Clark stated that “color, like form, has three dimensions”. Hue which is the name of the radiant energy. Chroma , which is the saturation of the hue Value, which is the relative lightness or darkness of the colour. 49

50. MUNSELL color order helps to visualize and organize color. HUE - in Munsell’s words, “it is that quality by which we distinguish one color family from another. Generally there are six hue families, violet, blue, green, yellow, orange and red. For example, in the vita shade guide there are four hues A, B, C and D denoting reddish brown, reddish yellow, grayish and reddish grey respectively. 50

51. CHROMA - in Munsell’s words, “it is the quality by which we distinguish a strong color over weak ones ”. Human teeth fall into the yellow to yellow red area of the Munsell color order system. Pale colours have a low chroma whereas intense colors have high chroma . VALUE - value or brilliance is the relative blackness or whiteness of color. On a scale of black to white, white has “high value”, black a “low value” and midway between the black and white is the medium grey. Value is the only dimension of colour that can exist by itself. 51

52. Principles of Shade Selection Teeth to be matched must be clean Remove bright colors from field of view - makeup / tinted eye glasses - bright gloves - non neutral operatory walls View patient at eye level Evaluate shade under multiple light sources Make shade comparisons at beginning of appointment Shade comparisons should be made quickly to avoid eye fatigue 52

53. Commercial Shade Guides Most convenient and common method of making shade selections Guides consist of shade tabs Metal backing Opaque porcelain Neck, body, and incisal color Select tab with the most natural intraoral appearance Vita Classic Vitapan 3D –Master Extended Range Shade Guides 53

54. Vita Classic Shade Guide Tabs of similar hue are clustered into letter groups A (red-yellow) B (yellow) C (grey) D (red-yellow-gray) Chroma is designated with numerical values A3 = hue of red-yellow , chroma of 3

55. Red/Yellow Yellow Grey Grey Red/Yellow 55

56. Manufacturer recommended sequence for shade matching Hue Selection Chroma Selection Value Selection Final Check / Revision Four categories representing hue A, yellow-red B, yellow C, gray D, red-yellow-gray Operator should select hue closest to that of natural tooth Use area of tooth highest in chroma for hue selection Difficult to select hue for teeth low in chroma 56

57. Hue selection has been made (B) Chroma is selected from gradations within the B tabs B1, B2, B3, B4 Several comparisons should be made Avoid retinal fatigue Rest eyes between comparisons (blue-gray) Use of second, value ordered shade guide is recommended Value oriented shade guide B1, A1, B2, D2, A2, C1, C2, D4, A3, D3, B3, A3.5, B4, C3, A4, C4, Value best determined by squinting with comparisons made at arms length Decreases light Diminishes cone sensitivity, increases rod sensitivity Tooth fading first has a lower value 57

58. OPACITY & TRANSLUCENCY: As light strikes a surface, it is either totally reflected, totally absorbed or a combination of both. Opaque objects reflect all or most of the light that is incident on them whereas transparent objects transmit all of the light that is incident on them. 58

59. Translucency, in effect is the three dimensional facial relationship or representation of value. Highly translucent teeth tend to be lower in value, since they allow light to be transmitted through the teeth, while opaque teeth have higher values. To mimic natural teeth the effective use of restorative materials should largely depend upon mimicking the translucent or opaque effect. 59

60. METAMERISM: The change in color perception of two objects under different light sources is called metamerism . This can be attributed to the difference in the radiant energy of two different wavelengths of light. The standardization of lighting condition during shade matching diminishes the effect of metamerism . 60

61. The emission of light by an object at a different wavelength from that of an incident light is called fluorescence. The emission stops immediately on removal of incident light. Teeth fluoresce with a stimulus in range of 340nm-410nm. This spectrum is the blue range. Thus, according to the principle of additive color, the emitted blue light acts with the yellowness of the tooth to produce a white tooth. Fluorescing pigments incorporated in the ceramic restorations by the ceramist and in the composite restorations by the manufacturer may thus be advantageously used in altering the perception of final result . GLOSS- Gloss is an optical property associated with a smooth surface that produces lustrous surface appearance and reduces the effect of color differences. FLUORESCENCE 61

62. PERCEPTUAL ASPECTS - THE ART OF ILLUSION Illusion is a figament of imagination where a perception of an object is created. FUNDAMENTALS AND PRINCIPLES- The art of creating illusion consists of changing perception, to cause an object to appear different from what it actually is . Teeth can be made to appear smaller, larger, wider, narrower, shorter, longer, younger, older, masculine or feminine. 62

63. Illusion works on two basic principles, which are the illusion of principles of illumination and the principle of line . The most important of these is the perception that light approaches and dark recedes. This is termed as “principle of illumination”. The second artistic prediction of great importance in dentistry is the use of horizontal and vertical lines and ridges. Horizontal lines make the objects appear wider and vertical lines make the object appear longer. This is termed as the principle of line. The artistic predilection exhibited in the principle of illumination can be maintained to change the size, shape and the overall form of the tooth through illusions. 63

64. Narrowing illusion Widening illusion 64

65. Lengthening illusion Shortening illusion 65

66. LAW OF TOOTH FACE: The face of a tooth is that area on the facial form on both anterior and posterior teeth, that is bound by the transitional line angles as viewed from the facial i.e.., labial or buccal aspect. These transitional line angles mark the transition from the facial surface to the mesial, distal, cervical and incisal surfaces. The tooth surface slopes lingually in the mesial and distal region while it slopes cervically from the line angles towards the root surface. Whenever there is no transitional line angle demarcating the incisal portion of the facial surface, the face is bound by the incisal edge as the occlusal tip. 66

67. The law of the face implies making dissimilar teeth appear similar by making the apparent faces equal. The apparent face should be manipulated, not the actual face. This is more importantly in the canine and the posterior as the “apparent face”. The transitional line angles are relocated so that the apparent face looks equal . Similar faces produced attract light and appear highlighted while the dissimilar areas that are in a shadow appear to recede. 67

68. ESTHETIC CONTOURING INDICATIONS Alteration of tooth structure Correction of developmental anomalies Minor orthodontic problems Removal of stains & discolorations Periodontal problems – trauma from occlusion Bruxism Reshaping & rounding of the corners of CI & LI to give more youthful look. CONTRAINDICATIONS Hypersensitivity of teeth. Large pulp canals Thin enamel Deeply pigmented stains Occlusal interferences Susceptibility to caries Extensive anterior crowding & occlusal disharmony 68

69. TECHNIQUES OF ESTHETIC RECONTOURING: Achievement of illusions The purpose of planning is to determine how to achieve an illusion of straightness. This process must include different views and perceptive. An optical illusion must work most effectively in the position from which most people would be viewing the patient Developmental grooves play important role in creating illusion. If the grooves are placed more apart illusion of more wide teeth can be created & vice versa. If there is dark pigmentation in the periphery and light in central portion of the facial aspect of tooth an illusion of narrow teeth can be created. 69

70. Angle of correction A lower incisor that actually or apparently, extends above the lower incisal plane is quite noticeable. The angle of view is important specially in shaping lower teeth. Because of the angle of view, an anterior teeth which is in linguoversion appears to be much more prominent than the one in labioversion. To contour the tooth in linguoversion, its incisal edge should be beveled lingually. Reduction reshaping of the natural dentition must always be in relationship to the lip position in both speaking and smiling. In rare cases it may be necessary to desensitize the tooth - sodium fluoride or a dentin sealer. with the use of water, it is often possible to see a slight color shift before the enamel is completely penetrated. The last few layers of enamel are more translucent so that the yellow dentin becomes more visible. Enamel removal should be stopped as soon as color shift is observed and hopefully before Anterior teeth in the lower arch should be shortened only to the level where they still occlude in protrusive movements. 70

71. Reduction is accomplished by carefully shaping the marked areas with the bulk reduction diamonds except for the lower anterior teeth. Bulk reduction in these teeth should be done with fine finishing diamonds at high speed. Final shaping on the mesial, distal, incisal and embrasure is done with the thin and the extra thin diamond points, because their shape allows for better access to these areas. This is followed by the white or green finishing stone. 71

72. ALTERATION OF TOOTH FORM: A canine that has drifted or been repositioned into the space of an extracted or a congenitally missing lateral incisors can sometimes congenitally be reshaped to resemble the missing tooth. Another example is to remove the part of the lingual cusp and reshaping of the labial surface of a first bicuspid so that it resembles a cuspid. 72

73. PEG SHAPED LATERALS: Treatment options 1. No treatment, patient not concerned 2. Orthodontic treatment first to align the teeth in the arch 3. Direct composite bonding onto peg laterals 4. Indirect composite placement 5. Bonded crowns 6. Porcelain bonded to metal crowns (Bello 1997) 7. Crown lengthening surgery to get better gingival heights. 8. Extractions and implant placement 9. Combinations of treatment in different sequences 73

74. ESTHETICS WITH COMPOSITES The conservative treatment approach is best collaborated with the use of composite due to their ability of bonding to many surfaces of natural teeth. This has opened many avenues for the use of these materials for esthetic benefits in cases that probably could not be treated effectively or at all in their absence. The results with these materials are quick, esthetic, economical , repairs are easy and the material does not require unnecessary tooth reduction for their placement. In most instances the final results are all in the control of the dentist without the involvement of laboratory technicians thus providing the dentist an opportunity to exhibit his skills. 74

75. BENEFITS OF DIRECT COMPOSITES: 1. Preserve sound tooth structure 2. Can be placed directly onto the tooth surface 3 . Can place as a type of direct composite veneer 4. It is a conservative restoration 5. Can easily change the emergence profile and angle 6. Can alter the shapes and length of the tooth 7. Can close diastema. 8. Can be used as an interim restoration in an adolescent and added to as the gingival heights matures 9. Can be repaired easily 10. Can be polished and repolished to a high shine 11. Long lasting 12. Not expensive treatment option 75

76. DISADVANTAGES OF DIRECT COMPOSITES: 1.Can chip and break 2. Can discolor if older composite used 3. Can develop marginal leakage (Walls 1988) 4. Can pick up stain easily in those patients who smoke and have poor oral hygiene 5. Can have a deleterious effect on gingival health on patient with poor oral hygiene (Walls 1988) 76

77. CONSIDERATIONS FOR PREPARATION DESIGN FOR ANTERIOR TEETH Though the preparation design for composite resins do not follow a prescribed pattern, they are essentially made as conservative as possible, leaving as much enamel as possible for effective bonding. This is done keeping desired final esthetics of the restorations in mind. The preparation design for anterior composite restorations should encompass elimination of decay, function and longevity and esthetic predictability. 77

78. The facial form of all anterior teeth can be divided into various facial planes, which converge or diverge from each other. These planes reflect or refract light and give a texture to the facial surface. The areas between any two planes are relatively prominent and hence extensions of the margins of the preparation should be kept away from those prominent areas. Extension for functional esthetics(EFE) is achieved using a long bevel extending a few millimeters, from the cavity margin and ending on a relatively flat area on one of the planes. The EFE ensures that the margin of the restoration overlays the defects. The esthetic advantages are:- Successful masking of the defect Better marginal adaptation Natural transition of shade between composite and tooth Ease of finishing and texturing. 78

79. PLACEMENT OF COMPOSITE FOR CARIOUS TEETH:- When the caries involves the labial surface of the EFE, follow the general guidelines explained earlier, following the facial planes. However in cavities having palatal access, leaving a thin shell of enamel of facial surface is not recommended as it is difficult to blend the composite restoration with the rest of the tooth. In such cases the labial unsupported enamel is reduced and the composite is extended on the facial surface. If the carious lesion is large , then a full facial veneer preparation may be the best option for optimal esthetic results. 79

80. During the placement of composite in the proximal areas, a mylar/metal strip is placed between the preparation and adjacent tooth while acid etching and bonding. A small amount of flowable composite is placed along the wall and cured. A layer of an opaque hybrid composite is placed more on the palatal half of the restoration and also in conditions where palatal wall is absent. This blocks the path of light passing through and through giving a grey translucency to the restoration 80

81. CLASS III RESTORATION Shade selection for the class III composite can be both time consuming and frustrating. The major problem is choosing the shade that will actually match after you have inserted and finished the restoration. Typically, the first thing you do is place a sample of intended material on the tooth to be restored. The difficulty is to anticipate the correct amount of material thickness so the final result will match. A good method of accomplishing this is to vary the thickness of sample by pressing harder on one end by mylar strip so you will get a gradation of colour, and therefore get a better indication of just how close your shade will match with the estimated thickness. 81

82. CLASS IV RESTORATIONS Those, including chipped or fractured teeth, are one of the top reasons for using composite resins. Frequently bonding is the ideal solution, providing both an immediate answer to an esthetic emergency and a long term, low cost restoration. CLASS V RESTORATIONS Generally microfill composites are choice of materials but recently nanocomposites are being used as they provide strength as well polishabilty similar to microfilled. When making a shade selection for class V restorations, first note patient’s lip line. This is particularly important for patients with a medium lip line where the incisal most margin will show during a wide smile. there is a shadow created with the lip line that tends to emphasize the grey shades. Therefore avoid translucent shades if possible, and select the more opaque shades for better blending. 82

83. LABIAL VENEERS The quickest and the most economic method of obtaining an esthetic tooth transformation is through the direct resin labial veneer. The best candidate for the direct resin veneer is the monochromatic shaded tooth, since multicolored restorations are much more easily constructed in the laboratory. 83

84. Minor malalignment can be corrected with minimal reduction of tooth structure by changing the tooth form in the preparation design to allow the composite restoration to recreate the desired form. In some of the cases, the preparation design resembles the one made to treat the minor fractures. Multiple malaligned teeth are viewed in totality and then individually. The most difficult tooth to be treated is marked and may be the ultimate guide on which the corrective treatment may be used, as it gives an idea of the limitations within which the dentist has to give an esthetic final result. 84

85. PLACEMENT OF COMPOSITE FOR DISCOLOURED TEETH Discolored teeth are usually challenging to treat. The dentist has to consider the masking of the dentin surface not only at the facial surface but at the cervical margins and incisal edges. A facial veneer is usually preferred for such situations. The preparation should allow a uniform thickness of composite to create a polychromatic appearance in the final result. In cases of severe discoloration the depth of preparation should allow an additional thin layer of opaque composite to mask the dark dentin. 85

86. In some cases the incisal edges need to be covered with composite extending on the palatal surface. The margin of the restoration should be kept subgingival whenever possible. Intracrevicular margin placements in discoloured teeth are unavailable for polishing hence restoration margins have to be superiority finished, for easy maintenance. 86

87. PLACEMENT OF COMPOSITE FOR CLOSING SPACES Diastema may be manifested due to microdontia, discrepancy between tooth size and the available ridge and also due to variation in the tooth morphology. Although some natural spaces may be esthetically and phonetically acceptable, others are not, and need corrective restorative procedures. cases where the size of teeth is normal and a diastema still exists, restorative creations using principles of illusion is recommended. 87

88. Boundaries of these space are assessed apico-coronally and mesio -distally as they will differ with the location of the interdental papilla and the proximal contours of the teeth. In periodontally treated cases, there could be papillary loss resulting in the back triangle effect. These closing spaces in such cases may pose a challenge as the dentist may have difficulty to maintain the tooth form, tooth preparations as well as allow good gingival contours for favorable gingival response. Sometimes an excessive frenal tissue makes it difficult for the dentist to restore this area and a frenectomy may be advised in some cases. 88

89. When diastema is small (2mm) – no tooth preparation required. Diastema between 2 angle-4mm – EFE should be given on the proximal surface of the labial curvature of the tooth. The extension preparation is close to the gingival margin and follows the contours of the interdental papilla to end on the palate-proximal line. diastema larger than 4mm-- a similar preparation coupled with recontouring of the other proximal surface of the tooth to maintain tooth proportions and form may be required. 89

90. Diastema are filled in one teeth at a time . Acelluloid matrix is effectively used to get the desired contour. In the diastema, opaque composites are used to build up a palatal wall followed by placement of hybrid composites of the desired shade on the palatal and cervical aspect of the cavity. Microhybrid or microfilled composites are then used as the final layer 90

91. Overlapping/ mal-aligned central incisors: The main objective is correcting overlapping incisors to remove as much as possible of the tooth structures that overlaps the adjacent tooth by contouring the labial aspect of the labially malposed tooth. This straightens the portion that overlaps the adjacent tooth and makes the long axis of teeth more parallel to each other. The incisal embrasure between the teeth is reopened to at least 0.25 to 0.50mm length. 91

92. 92

93. ESTHETICS WITH CERAMICS In many dental practices, the ceramic crowns and bridges are one of the most widely used fixed restorations. This has resulted part from technologic improvements in the fabrication of restoration by dental laboratories and in part from growing amount of cosmetic demands that challenge dentists today. Metal ceramic and all ceramic restorations have excellent esthetic potential. All ceramic restorations are characterized by a dentin like core which makes it possible to mimic the translucency of natural teeth. They are biocompatible with the gingival tissue and exhibit excellent marginal fit due to newer thermoplastic processing while some exhibit wear resistance similar to enamel. 93

94. PRE-OPERATIVE ANALYSIS A preoperative model would help in determining the length, the labio-lingual thickness, the convexity and taper of tooth. The position of the cingulum and occlusion will help to determine the extent of preparation. X-rays help in determining the pulpal morphology and crown-root ratio. 94

95. INDICATIONS OF METAL CERAMIC CROWNS Tooth requiring full coverage with high demand for esthetics. Retainer for fixed partial denture. Extensively destroyed teeth as a result of caries, trauma, or existing previous restorations with a need for superior retention and strength. Need to re-contour axial surface or correct minor malocclusions. CONTRAINDICATIONS Patients with active caries or untreated periodontal disease. Young patients with large pulp chambers. When an intact buccal wall is present. When the use of more conservative retainer is possible. 95

96. ADVANTAGES Combines the strength of all metal crown with the esthetics of an all ceramic crown. Excellent retentive qualities as axial wall is included. Easy correction of axial forms. DISADVANTAGES Removal of substantial tooth structure. Subject to fracture because porcelain is brittle. Difficult to obtain accurate occlusion in glazed porcelain. Shade selection can be difficult. Inferior esthetics compared to all ceramics. Expensive. 96

97. ALL CERAMIC RESTORATIONS: Indications High esthetic requirement. Considerable proximal caries where the tooth can no longer be restored by composite resin. Incisal ridge reasonably intact. Favorable distribution of occlusal load. Contraindications When superior strength is required then metal ceramic crown is more appropriate. High caries index. Insufficient coronal tooth structure for support. Thin teeth faciolingually. Unfavourable distribution of occlusal load. Bruxism. 97

98. Advantages Esthetically unsurpassed Good tissue response even for subgingival margins. Slightly more conservative of the facial surface as lack of reinforcement by metal substructures. Disadvantages Reduced strength compared to metal ceramic crowns. Proper preparation extremely critical Least conservative preparation. Brittle nature of material. Can be used as single restoration only 98

99. Goals for achieving maximum esthetics… 99

100. VENEERS It is a layer of tooth colored material that is applied to a tooth to restore localized or generalized defects and intrinsic discoloration. INDICATIONS: Discolorations Enamel defects Diastema Malpositioned teeth Faulty / poor restorations Aging Wear patterns Malformed lateral incisors 100

101. CONTRAINDICATIONS: Ability to etch enamel – deciduous & fluoridated teeth Bruxism Available enamel is thin Teeth with severe crowding 101

102. TYPES … Directly fabricated veneers- These are composite resin materials applied to the tooth surface free hand by clinician. Indirectly fabricated veneers- Those are labio rotary fabricated veneers developed on the cast of the patient mouth, this category can be further subdivided to the material used- Composite Porcelain Two types of esthetic veneers exist- Partial veneer - Are indicated for the restoration of localized defect or area of intrinsic discoloration. Full veneers - Indicated for the restoration of the generalized defect or area of intrinsic staining involving the majority of the facial surface of the tooth. 102

103. PORCELAIN LAMINATE VENEERS: ADVANTAGES: Color Bond strength Periodontal health Resistance to abrasion Inherent porcelain strength Resistance to fluid absorption esthetics DISADVANTAGES: Time Repair is difficult once luted to enamel Technique sensitive Difficulty in color modification Tooth preparation Fragility of porcelain Cost is high 103

104. Enamel reduction must be considered from five different aspects:- Labial reduction – 0.3 mm at cervical, 0.5mm in middle , 0.7 mm in incisal ; chamfer finish line Interproximal extension - continued from the distal papilla tip to the distal of the contact zone Sulcular extension – 0.5 mm supragingingival or 0.05 to 0.1 mm subgingival Incisal or occlusal modification- 0.75 to 1mm , Lingual reduction – butt joint of incisolingual junction IMPRESSION 104