Veneers in conservative dentistry and endodontics

Veneers in conservative dentistry and endodontics

1. Dental Veneers

2. Contents Introduction History Types of Veneers Design of Different Preparation Material Used Case Selection Direct Veneers Indirect Veneers Technique For Direct Veneers

3. Content Technique For Indirect PorcelimVeneers -Armamentarium Actual Material Preparation Try In & Bonding Maintenance & Failures Conclusion Bibliography

4. The demand for tooth colored restorations and a more attractive smile has now passed the boundaries of exclusive practitioners, specialists & the esthetic centers all over the world. As esthetically pleasing restorations of young fractured malformed or discolored teeth has been a perplexing problem for dentists, in the past few years a conservative approach to improve the esthetic appearance has led widespread use of veneering systems.

5. Introduction A veneer is a layer of tooth-colored material that is applied to a tooth to restore localized or generalized defect and intrinsic discolorations. --(Sturdevant's art & science operative dentistry 6 th Edition) A veneer is a layer of tooth colored material that is applied to a tooth for aesthetically restoring localized or generalized defects or intrinsic discolorations. -GPT Porcelain veneers are thin-bonded ceramic prosthetics that restore the facial surface and part of the proximal surfaces of anterior teeth that require esthetic treatment. -GPT

6. History

7. History The method of fabrication has not evolved too much since 1980, although the potential of bonded ceramics is well known, due to their ability to fulfill the biomimetic principle.

8. Classification of Veneers

9. Types Of veneers Partial veneers Full veneers Partial veneers are indicated for the restoration of localized defects or areas of intrinsic discoloration. Full veneers are indicated for the restoration of generalized defects or areas of intrinsic staining involving most of the facial surface of the tooth.

10. Type of veneer's According to method of Fabrication

11. basic preparation designs exists for full veneers: Window preparation Incisal, lapping preparation Incisal butt joint preparation

12. Window preparation

13. Incisal-lapping preparation

14. Incisal butt joint preparation

15. Direct Composite Veneers

16. Indications The use of directly applied resin composite to restore worn teeth was first described by Bevenius et al. in this method direct composite resin is applied on prepared tooth surfaces Absence of necessity for tooth preparation low cost for patients compared with indirect techniques and other prosthetic approaches, reversibility of treatment and no need for

17. composite veneers Advantages One visit procedure Less expensive Repair potential Chair-side control of the anatomy Minimal irreversible loss of tooth structure. Disadvantages Tend to discolored Wear out quickly Marginal staining Shade matching difficulty Often require repair and replacement.

18. Procedure for direct composite Veneers

19. Case selection

20. Shade Selection

21. Silicon Matrix preparation

22. Silicon Matrix preparation

23. Tooth preparation. The silicone matrix was placed to check facial and incisal reduction.

24. Finishing & Polishing Composite

25. INDIRECT Veneers

26. Indirect Composite Veneers Superior properties Superior shading and characterizing Better control of facial contours Easily repaired Children and adolescents as interim restorations Wear pattern Lower cost

27. Types of IRCS First-generation IRCs Touati and Mφrmann introduced the first generation of IRCs for posterior inlays and onlays in the 1980s. Direct resin composites were composed mostly of organic resin matrix, inorganic filler, and coupling agent. The first-generation IRCs had a composition identical to that of the direct resin composite marketed by the same manufacturer and the materials also bore names similar to that of the direct materials. Upon light initiation, camphoroquinone decomposes to form free radicals and initiates polymerization, resulting in the formation of a highly cross-linked polymer. It is observed that 25%-50% of the methacrylate group remains unpolymerized . Ivoclar was SR- Isosit ® Clearfil CR Inlay ®  (Kuraray), which uses light and heat for the indirect technique. Conquest ®  ( Jeneric / Pentron ), EOS ®  ( Vivadent ), and Dentacolor ®  ( Kulzer ) use only heat for additional curing, whereas Visio-Gem ®  (ESPE-Premiere) uses heat and vaccum for additional curing. It is possible to use any posterior composite for indirect technique with additional curing.

28. second-generation composites Clinical failures endured with first-generation composites and the limitations faced with ceramic restorations led to the development of improved second-generation composites. The improvements occurred mainly in three areas: structure and composition, polymerization technique, and fiber reinforcement‘ microhybrid ' filler with a diameter of 0.04-1 μ, which is in contrast to that of the first-generation composites that were microfilled . The filler content was also twice that of the organic matrix in the latter composites. By increasing the filler load, the mechanical properties and wear resistance is improved, and by reducing the organic resin matrix, the polymerization shrinkage is reduced. The new composite resins like Artglass ®  and belleGlass HP ®  contain high amounts of filler content, which make them adequate for restoring posterior teeth. Others, such as Solidex ®  ( Shofu Inc.), have intermediate filler loading, which enables better esthetics and are preferred for anterior tooth.

29. Polymerization techniquese Heat polymerization First, the residual monomer would be covalently bonded to the polymer network as a result of the heat treatment, leading to increase in the conversion itself Second, unreacted monomers would be volatilized during the heating process. The combination of heat and light increases the thermal energy sufficiently to allow better double-bond conversion. This concept was first used by Heraeus-Kulzer in the development of Charisma ®  . It was observed that the wear resistance increased by 35% on curing with both light and heat when compared to curing with light only. Nandini S. Indirect resin composites. J Conserv Dent 2010;13:184-94

30. Nitrogen atmosphere  Oxygen entrapment in the restoration tends to break up or diffract natural light as it reflects from the surface of the restoration.  Such a condition will increase their stiffness, disallowing further propagation of the molecule. Such a concept is incorporated in the curing process for both belleGlass ®  and Cristobal ®

31. Soft start or sow curing The concept of slow curing described by Mehl  is based upon the concept that a slower rate of curing will allow a greater level of polymerization . Faster rates of polymerization tend to prematurely rigidify the newly formed polymerized branches. Such a condition will increase their stiffness, disallowing further propagation of the molecule. Such a concept is incorporated in the curing process for both belleGlass ®  and Cristobal ®  .

32. Electron beam irradiation The two main reactions that occur when a polymer is subjected to electron beam irradiation are chain breakage and chain linkage . When breakage of chains occurs at the region of entanglement, there is induction of dense packing. This influences the bond between the filler and matrix, thus improving the mechanical properties and increasing success rates. The possible disadvantage of this method is polymer degradation and discoloration of the resin. The radiation dosage usually given is 200 KGy , but lower dosage like 1 KGy also has been shown to improve the properties.  Due to economic reasons it is impossible to irradiate single crowns or FPDs. Behr and Rosentritt demonstrated that irradiated raw materials of composites can be mixed with new material to improve properties.

33. Fiber reinforcement Fiber -reinforced composites were introduced by Smith in the 1960s . Polyethylene fibers , carbon/graphite fibers , Kevlar ®  , and glass fibers   were tested. Glass and polyethylene are the commonly used fibers in dentistry. Fibers act as crack stoppers and enhance the proprety of composite . The resin matrix acts to protect the fiber and fix their geometrical orientation. Boron oxide, a glass-forming agent is present at 6-9 wt % in E- fibers and <1 wt % in S- fibers . E- and S- fibers are the ones most commonly used in dentistry. The fibers can be arranged in one direction (unidirectional), with the fibers running from one end to other in a parallel fashion.

34. Indirect Porcelain Veneers

35. Indication M agne and Belser presented the following classification for indications for ceramic veneers Type I: Teeth resistant to bleaching Type IA: Tetracycline discoloration Type IB: Teeth that are unresponsive to bleaching Type II: Major morphologic modifications Type IIA: Conoid teeth Type IIB: Diastema or interdental triangles to be closed Type IIC: Augmentation of incisal length or facial prominence Type III: Extensive restorations Type IIIA: Extensive coronal fracture Type IIIB: Extensive loss of enamel by erosion and wear Type IIIC: Generalized congenital malformations.

36. Contraindication Available enamel Ability to etch enamel; the bonding of laminates is a micro-mechanical process of etching. Deciduous and highly fluoridated teeth may not etch effectively. Oral habits; bruxism and nails and foreign object bite. Porcelain withstands compressive force than shearing stress. Patients with high caries index. Compromised periodontal health. Endodontically treated teeth; a full crown would hold the integrity of the non vital teeth than a veneer. Teeth with gum recession

37. Type I Include excessively discolored teeth as a result of tetracycline stains (degrees III and IV according to Jordon & Boksman Jordan and Boksman in 1984 classified tetracycline-stained teeth into four degrees of staining, based on the severity of discoloration. 1.Teeth with yellow to gray stains without banding and with uniform color spread throughout the teeth were classified as mild lesions, or first-degree tetracycline-stained teeth. 2.Teeth with yellow-brown to dark gray stains without banding were classified as moderate lesions, or second-degree. 3.Teeth with blue- gray or black stains and significant banding across the surface were classified as severe lesions, or third-degree. 4.Finally, teeth with stains so severe that tooth bleaching is ineffective were classified as intractable staining, or fourth degree

38. Type I: Teeth resistant to bleaching Excessively discolored teeth as a result of tetracycline stains (degrees III and IV according to Jordon & Boksman type I‐A )

39. type I‐B Type IB: Teeth unresponsive to external and internal bleaching: This category includes, for example, teeth with exposed dentin and pulp less teeth.

40. Major morphologic modifications: Type II-A Conoid teeth

41. Type II- B Closure of Diastema and interdental black triangles

42. Type ii c-Augmentation of incisal length and prominence

43. Type III: Extensive restoration in the adult: Extensive coronal fractures (type IIIA)

44. Extensive loss of enamel (type IIIB)

45. Malformations (type IIIC)

46. Porcelain Materials for Veneers Several porcelain materials can be used for the fabrication of veneers and they can be classified into five groups Heatpressed ceramic; Computer-aided manufacturing (CAD/CAM) processed factory produced ingots; Feldspathic porcelain baked in the traditional water-slurry method; and Feldspathic porcelain over foil-matrix with refractory die technique. Castable glass ceramic

47. Feldspathic veneers Created by layering glass-based (silicon dioxide) powder and liquid materials. Silicon dioxide, also referred to as silica or quartz, contains various amounts of alumina. Feldspars -When aluminum silicates are found naturally and contain various amounts of potassium and sodium. Feldspars -silicon oxide (60%–64%) and aluminum oxide (20%–23%), -Modified in different ways to create glass that can then be used in dental restorations. Thus, porcelain veneer consists of fluorapatite crystals in an aluminum -silicate glass that may be layered on the core to create the final morphology and shade of the restoration.

48. Mechanical properties are low. Flexural strength usually from 60 to 70 MPa . The ideal conditions for the bond between the veneer and the substrate are Presence of a rate of 50% or more of the enamel remaining on the tooth; 50% or more of the bonded substrate being enamel and 70% or more of the margin being in enamel

49. Glass-based ceramics Improved mechanical and physical properties. Increased fracture resistance, improved thermal shock resistance, and resistance to erosion. Improvement in properties depend on the interaction of the crystals and glassy matrix, as well as on the size and amount of crystals. Finer crystals generally produce stronger materials. They may be opaque or translucent, depending on the chemical composition and percent crystallinity . For aesthetic veneers, ceramics reinforced by leucite and lithium disilicate are commonly indicated for their optical properties and because they are acid-sensitive

50. Both leucite and lithium disilicate are fabricated through a combination of lost-wax and heat-pressed techniques. The microstructure is similar to that of powder porcelains; however, pressed ceramics are less porous and can have a higher crystalline content because the ingots are manufactured from nonporous glass ingots by applying a heat treatment that transforms some of the glass into crystals.

51. Treatment Plan Determining the Essential Pre-operative Evaluation ( Analyzing the Smile) Composite Mock-up Diagnostic Study Models Wax-up for Tooth Preparation Aesthetic Pre-countering Actual Material Prep Try in and Bonding Maintenance and Failure

52. Determining the Essentials Tooth Position Biomimetics , one of the new terms Introduced to the dental glossary by Magne , et al.,Refers to the reproduction of the original performance of the intact tooth that is about to be restored. Gingiva The soft tissues and bone height in relation to adjacent teeth should always be taken into account to avoid gingival asymmetry and to maintain the height of the interdental papillae.

53. Gingival Margins The cervical placement of the PLV margins is also an important issue to be taken into consideration. Although the laminate veneer’s Ideal margins are preferably located on the enamel and away from the gingiva , the condition of the teeth must always be apprised before deciding on any form of treatment. Occlusion Occlusal relations, heavy function or parafunction play vital roles in PLV applications. Age & Sex Aged or worn-out teeth exhibit different thicknesses of enamel and surface texture that are directly related to the extent and distribution of the occlusal interferences or external stimuli. Photography and Videotaping

54. Composite Mock-up A diagnostic “composite mock-up” which is the direct application of composite without surface preparation that perches itself on the teeth, is indicated when such elements are missing, or when an alteration of tooth forms is necessary. They serves following functions The composite mock-up is both diagnostic and informative Determining the Incisal Edge Position Determining the Gingival Line Short-term Provisionals

55. Diagnostic Study Models Study casts as a reference for use in the laboratory are a necessary requirement, whether for provisional or permanent prostheses. Transferring the Mock-ups The best way to transfer this information to the lab is with an alginate or silicon impression made from the composite mock-up, which is simpler and self-explanatory. It is the ideal way of transferring the incisal edge’s position and its inclination to the lab. Photography Silicone Index

56. Wax-up for Tooth Preparation One of the very crucial issues in the production of PLVs is to keep the maximum existing enamel of the tooth structure. Before the dentist even starts the treatment planning, and especially when treating the aged tooth with PLV, the amount of remaining enamel and the final volume of the PLV should be very carefully analyzed .

57. Aesthetic Pre- recontouring (APR) The final esthetic and functional form determines the actual tooth preparation and entire PLV buildup we seek to achieve. These two parameters will set the starting point of the whole treatment. APR should start by adjusting the incisal edge position, and then should be followed by redirecting the angle of the mid-line perpendicular to the incisal edge and the infraorbital line, if necessary.

58. Factors affecting APR Position of Teeth

59. These two parameters will set the starting point of the whole treatment. APR should start by adjusting the incisal edge position, and then should be followed by redirecting the angle of the mid-line perpendicular to the incisal edge and the infraorbital line, if necessary. Use a simple silicon index that is prepared from the diagnostic wax-up. By placing this customized index over the teeth, the dentist can visualize the teeth or a portion of a tooth that creates the disharmony, either by a facial protrusion or unnatural axial inclination Incisal Edge Position and the Mid-line

60. Facial Contours How To Exact the Contours

61. After exacting facial contours

62. Aesthetic Pre-evaluative Temporaries (APTs) Lingually Positioned Teeth

63. Aesthetic Pre-evaluative Temporaries (APTs)

64. Clinical Tips for Ceramic Laminate Veneer Shade Selection Multiple Units 1.Establish a properly lighted environment for shade selection. 2. Select the final shade of the veneers, based upon the patient’s preference as well as the tone of hair, eyes, and skin. 3. Take a photograph of the selected shade tab adjacent to the unprepared tooth structure as a reference shade for the technician 4. Select the original shade of the hydrated unprepared tooth structure as a reference point.

65. 5. Select the stump shade after the final tooth preparation. Note that the stump shade can vary within each tooth as well as Interproximally (between the teeth). This importance and clinical significance of this step cannot be overemphasized. 6. Take a reference stump shade photograph for the technician. 7. Always use a try-in or trial cement prior to the definitive luting in order to verify the final shade and acquire patient approval. Note that dual cure cements are prone to slight changes in value owing to degradation of ben- zoamines In the luting agent. The final color effect will be slightly lower In value (darker). The final shade is indicative of a laminate of materials as well as underlying tooth structure.

66. Instruments do not create beauty, people do.

67. Depth Cutters 868A.314.018 and # 868A.314.021) control the depth of the facial tooth preparation.

68. In the “minimal” preparation, the teeth that are about to be restored are no more than one shade different from the proposed final PLV restoration Depth of 0.2 mm is needed to change the hue of the tooth by one shade.

69. The surface after the depth cutter is used in only one angle. Note that the only true depth is gained in the area of B (middle 1 /3rd, black dots). To reach the necessary depth on points A (gingival 1 /3rd, green dots) and C (incisal 1 /3rd, red dots), the bur should be used in three different angulations.

70. The depth cutters are used through the APT. This will provide the dentist with the minimal invasive preparation, The APT after the depth cutter is used. Note that remaining parts would have been uselessly prepared if the APT was not used, The horizontal grooves produced through APT. Note how shallow the grooves are.

71. Coating the surface of the tooth with a water insoluble tint allows the depths of the horizontal grooves to be more easily perceived. Note the horizontal grooves hardly reach to the distal of the central and mesial of the lateral. Any unnecessary entry is prevented by the preparation done through the APT.

72. The round ended fissure diamond bur is used in three different planes until all the color at the surfaces of the bottom of the grooves disappears. This will indicate that the true actual material preparation depth is fully achieved.

73. Preparing the Incisal 1/3rd The preparation must reproduce the natural convexity of a maxillary central incisor and provide for a minimum reduction thickness of 0.7 at the junction of the middle and incisal thirds of the tooth. Insufficient tooth reduction, in terms of leaving a sharp line angle and not rounding off the incisal labial area, is the leading cause

74. If the edge has a rounded surface at the incisal-labial, that reflected light is being diffused and yields an ideal transition of the shade from incisal color to body color

75. Gingival Preparation The fabrication of the PLV is directly affected by the placement of the finishing line. Smooth margins that are fully exposed and readily cleansable generally provide the best results. Whenever possible, the finish lines should be placed in the enamel following the contour of the soft tissue from mesioproximal to distoproximal . It is almost impossible to finish an accurately fitting PLV without being overcontoured over a knife-edge preparation at the cervical area. A chamfer is preferred for all the gingival margins.

76. Why Supragingival Margins

77. When the chamfer margin preparation is deeper than one-half of the width of the bur, a thin shell of reverse margin is occasionally left

78. ideal margin for a PLV. Enables us to reproduce a natural visible tooth profile while avoiding over contouring of the PLV in the cervical zone. Easy to record, identify and reproduce in the laboratory. Ideal continuation of the emergence profile, without any ledge at the junction of the veneer and enamel Allows the veneers to be more easily inserted at try-in, and during the final placement it provides a higher fracture resistance and avoidance of fractures at the edges of the PLV .

79. Proximal Preparation Aim must be to place the margins beyond the visible area and to preserve the contact area. Esthetics should be carefully considered when placing the proximal “stop-line”, providing that the teeth are free of proximal restorations.

80. Interproximal Preparation Proximal reduction is simply an extension of facial reduction. Using the same round-end tapered fissure diamond bur, the gingivoproximal reduction is continued by uprighting the angle of the bur vertically into the proximal area, making sure to maintain adequate reduction, especially at the line angle.

81. Preferably, the Interproximal margin should stay short of the contact area.

82. Magne and Douglas classified the penetration depths of the interprox - imal preparation as - “short wrapping” (the veneer to extend only to the facial margin of the tooth), “medium wrapping” (the veneer that extends into the bulk of the mesial or distal marginal ridge by penetrating 50% of the interdental area) “long wrapping” (the veneer which entails covering the entire interdental area).

83. Lingual Preparation (a) Palatinal view of central areas. Red (-) markings correspond to concavities that are proven to be the area of stress concentration, (b) The palatinal view of a canine. Due to the thick nature of the enamel and the longer cingulum , there is less stress concentration on the canine. Green (+) markings correspond to the conuexities where the palatinal preparation margin can be located.

84. The preparation lines on the lingual should not be located on the palatinal concavity. If a lingual preparation is to be done, this raises the important issue of where to finish the palatinal margins and how deep to prepare the lingual surface of the maxillary anteriors . Logically, the preparation should preferably not finish at the concavity but rather it should be placed either above the concavity or below on the smooth convex area of the cingulum so that they will be subject to low tensile forces

85. Finishing the Preparation A thorough examination of the prepared teeth is necessary. Especially at the junction of the incisal angle and the lingual reduction, the dentist must be careful to remove any sharp angles that might serve as a focal point for stress concentration. At the point where the facial, proximal and lingual planes of reduction meet, other sharp features that may have formed In the final preparation should be avoided and there should not be any sharp angles.

86. Checking the Prepared Surfaces Magnification systems Looking through the lens with 1:1 magnification; will most often surprise the dentist as many minor defects that would otherwise never be seen with naked eye, will be observed. Silicone index

87. Impression Making Impression of the whole arch should be made with a polyvinyl siloxane impression material. Before the impression is made, the impression tray should be coated with its special adhesive at least 15 minutes in advance. Retraction Cords If subgingival margins

88. Retraction cord placement Light body application

89. Impression Process Medium body application

90. Provisionalization Provisionalization is a practical means of obtaining feedback, on the esthetic parameters, from not only the patients, but the dentist and technician as well, since the subjectivity of a smile design can never be overemphasized. This will eliminate most of the guesswork which may be the cause of an imperfect esthetic and functional outcome. The fabrication of the provisionals can be classified into two groups, as Direct (intraorally) or Indirect (extra oral) prefabricated provisionals .

91. Technique for direct Provisional

92. Debonding Provisinals

93. Try-in The facial surface is cleaned by sandblasting, pumice or with a very light application of a course diamond fissure bur. Care should be taken to use very gentle pressure.

94. Individual Evaluation One of the most Important sites to be carefully checked at the try-in stage is the gingivoproximal area , since the marginal openings in that area have been proven to be two to four times larger than midlabially .

95. Collective Try-in

96. Bonding Composite resin, acid etched porcelain and etched enamel have been proven in vitro studies to derive from a strong, durable complex.

97. Application of hydrofloric acid 10 % Before HFL application After HFL application

98. Binding Procedures

99. Silane Application salty-looking appearance

100. Acid Etching

101. Adhsive Application

102. Bonding

103. After 1-2 seconds of light curing with the 13 mm-diameter curing tip. The excess luting resin that came out of the margins has a jelly consistency and can easily be cleaned with an explorer and brush dipped in a bonding agent.

104. Light Curing

105. Advances of veneers Lumineers Lumineers that are made from a special patented Cerinate porcelain that is very strong but much thinner than traditional laboratory fabricated veneers are currently in trend. The thickness is comparable to contact lenses. Lumineers are a reversible procedure and it hardly requires removal of tooth structure. They will bond directly to the tooth making the bond very strong and the longevity is more as up to 20 years. However, after all the treatment is confined to ideal patients Hari , M. and Poovani , S. (2017). Porcelain laminate veneers: A review.  Journal of Advanced Clinical & Research Insights , 4(6), pp.187-190.

106. Componeers This an innovative approach that bridges between ceramic veneers and direct composite veneering and overcomes the limitation of either approach. High quality, long-lasting esthetic restoration , i.e., both conservative and cost-effective . The shiny and naturally designed surface adds a look of vitality to the restoration. Precontoured enamel shells with excellent color stability, no laboratory procedure, cost-effectiveness provide an added advantage .

107. There is no difference in modifiability compared to a direct composite veneer and, however, its ease of application makes it extraordinarily time-efficient. However, unlike ceramic veneer, Can be easily repaired. Componeers are manufactured from nanohybrid composite that ensures excellent homogeneity and stability of the enamel shells. The extremely thin veneer (0.3 mm) allows conservation of tooth structure. The micro-retentive inner surface ensures a lasting bond, therefore, conditioning of the veneer is not required Chandramouli MK. Componeers . Int J Prev Clin Dent Res 2017;4(3):232-234.

108. Do’s & Don’ts Do’s Use a soft toothbrush with rounded bristles , and floss as you do with natural teeth. Use a less abrasive toothpaste. Use a soft acrylic mouth guard when involved in any form of contact sport . Ensure routine cleaning . Don’ts Avoid food or drinks that may contain coloring . Do not use alcohol and some medicated mouthwashes because they have the potential to affect the resin bonding material during the early phase (the first 48 hours). Avoid hard foods, chewing on ice, eating ribs and biting hard confectionaries and candy . Avoid extremes in temperature.

109. Longevity of porcelain veneers Beier et al. (2011) reported in a retrospective clinical study a survival rate of 94.4% after five years and 93.5% after ten years ; A randomised clinical trial done by Layton and Walton (2012) showed similar results, with a survival rate of 96% after ten years and 91% after 20 years . Also, Smales and Etemadi (2003) reported a survival rate of 95% for porcelain veneers throughout 7 years.

110. There are other studies which reported a lower survival rate for porcelain veneers . A retrospective study of 2,563 veneers in 1,177 patients done by Burke and Lucarotti (2009) reported a survival rate of 53% over 10 years . The material type of the veneers was not reported. Moreover, the study evaluated veneers that were done by the general dental service, and thus, it is possible that preparations of teeth did not meet the criteria of specialists’ level. A nother retrospective study was done by Shaini et al., (1997) reported a survival rate of 47% in 7 years . The veneers were done by undergraduate students and staff member at Birmingham University in the United Kingdom . The study reported that over 90% of veneers were placed on unprepared teeth, this can be a reason for high failure rate as it is suggested that the bond to aprismatic enamel is much weaker than prepared enamel (

111. Conclusion Porcelain veneers are highly aesthetic and conservative treatment yet it is very technique sensitive. For successful application veneers dentist should have thorough knowledge of case selection, careful treatment planning ,good communication with patient and lab technician to execute the finest result .

112. bibliography Galip Gurel - The Science and Art of Porcelain Veneers Alothman , Y., & Bamasoud , M. S. (2018). The Success of Dental Veneers According To Preparation Design and Material Type. , 6(12), 2402–2408. doi:10.3889/oamjms.2018.353 Pascotto , R., Pini , N., Aguiar , F., Lima, D., Lovadino , J. and Terada, R. (2019). Advances in dental veneers: materials, applications, and techniques. Vanlıoğlu , B. A., & Kulak- Özkan , Y. (2014). Minimally invasive veneers: current state of the art. Clinical, cosmetic and investigational dentistry, 6, 101–107. doi:10.2147/CCIDE.S53209 Pini , N. P., Aguiar , F. H., Lima, D. A., Lovadino , J. R., Terada, R. S., & Pascotto , R. C. (2012). Advances in dental veneers: materials, applications, and techniques. Clinical, cosmetic and investigational dentistry, 4, 9–16. Kanokrungsee T, Leevailoj C. Porcelain veneers in severely tetracycline-stained teeth: A clinical report. M Dent J 2014; 34: 55-69