Ceramic inlays and onlays

CERAMIC INLAYS AND ONLAYS

1. CERAMIC INLAYS AND ONLAYS Dr Pooja Jayan Dr Pooja Jayan

2. Contents

3. IN T ROD U CT I ON Dental ceramics are nonmetallic, inorganic structures, primarily containing compounds of oxygen with one or more metallic or semi-metallic elements (aluminum, boron, calcium, cerium, lithium, magnesium, phosphorus, potassium, silicon, sodium, titanium, and zirconium). According to Sturdevant, an onlay caps all cusps; an inlay may cap none or may cap all but one cusp.

4. HISTORY

5. IND I CATI O N S

6. SMALL TO MODERATE CARIOUS LESIONS Garber DA, Goldstein RE. Porcelain & composite inlays & onlays : esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

7. LARGE CARIOUS OR TRAUMATIC LESIONS Garber DA, Goldstein RE. Porcelain & composite inlays & onlays : esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

8. ENDODONTICALLY COMPROMISED TEETH Garber DA, Goldstein RE. Porcelain & composite inlays & onlays : esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

9. TEETH WHERE IT IS DIFFICULT TO DEVELOP RETENTION FORM Garber DA, Goldstein RE. Porcelain & composite inlays & onlays : esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

10. When metal allergy is a factor The restoration of teeth in an arch opposed by already present porcelain restorations

11. CONTRAINDICATIONS Garber DA, Goldstein RE. Porcelain & composite inlays & onlays: esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

12. ADVANTAGES Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12.

13. DISADVANTAGES Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12.

14. CLINICAL PROCEDURE

15. .

16. Thompson MC, Thompson KM, Swain M. The all ‐ ceramic, inlay supported fixed partial denture. Part 1. Ceramic inlay preparation design: a literature review. Australian dental journal. 2010 Jun 1;55(2):120-7.

17. Thompson MC, Thompson KM, Swain M. The all ‐ ceramic, inlay supported fixed partial denture. Part 1. Ceramic inlay preparation design: a literature review. Australian dental journal. 2010 Jun 1;55(2):120-7.

18. Garber DA, Goldstein RE. Porcelain & composite inlays & onlays: esthetic posterior restorations. Chicago: Quintessence; 1994 Jan.

19. RULE FOR CUSP CAPPING Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12.

20. RULE FOR CUSP CAPPING Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12. If cusps must be capped, they should be reduced 1.5 to 2 mm and should have a 90-degree cavosurface angle. When capping cusps, especially centric holding cusps, it may be necessary to prepare a shoulder to move the facial or lingual cavosurface margin away from any possible contact with the opposing tooth, either in maximum intercuspal position or during functional movements. Such contacts directly on margins can lead to premature deterioration of marginal integrity. The axial wall of the resulting shoulder should be sufficiently deep to allow for adequate thickness of the restorative material and should have the same path of draw as the main portion of the preparation

21. RULE FOR CUSP CAPPING Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12. For onlay restorations, nonworking and working cusps are covered with at least 1.5 mm and 2 mm of material, respectively. If the cusp to be onlayed shows in the patient’s smile, a more esthetic blended margin is achieved by a further 1- to 2-mm reduction with a 1- mm chamfer

22. RULE FOR CUSP CAPPING Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12.

23. CERAMIC INLAYS AND ONLAYS CAST METAL INLAYS AND ONLAYS THICKNESS/BULK More bulk needed , more Clearance Less bulk needed OCCLUSAL BEVELS Bevels contraindicated Bevels necessary GINGIVAL BEVELS Not necessary Needed to achieve minimal marginal gap CE R VICO- OCC L USAL DIVERGENCE 6 to 7 degrees of occlusal d i ver g e n ce 2 to 5 degrees per wall MARGINAL A D AP T A T ION Rely on adhesion between tooth structure/resin cement/porcelain to create a gap-free Rely on close adaptation (20um);lack of adhesion between tooth structure/cement/metal interface : gingival bevels are thus needed

24. CERAMIC INLAYS AND ONLAYS CAST METAL INLAYS AND ONLAYS PULPAL FLOOR Need not be flat and perpendicular to the long axis of the tooth; If the cavity is shallow ,pulpal floor should be indented in central fossa region parallel to the cuspal inclines. Flat and perpendicular to the long axis of the tooth INTERNAL LINE ANGLES Rounded internal line and point angles Well-defined internal line and point angles CAVOSURFACE ANGLE 90 Degrees butt joint 140 to 150 degrees( 30 to 40 degree marginal metal) CUSP REDUCTION Functional cusp: 1.5mm- 2mm Non-functional cusp : 1.5 mm Functional cusp: 1mm-1.5 mm Non-functional cusp : 1mm

25. IMPRESSION Tooth-colored inlay or onlay systems require an elastomeric or optical impression of the prepared tooth and the adjacent teeth and interocclusal records, which allow the restoration to be fabricated on a working cast in the laboratory. With chairside CAD/CAM systems, no working cast is necessary.

26. PROVISIONAL RESTORATION For exceptionally nonretentive preparations, or when the temporary phase is expected to last longer than 2 to 3 weeks, zinc phosphate or polycarboxylate cement can be used to increase retention of the provisional restoration. Resin-based temporary cements are also available (e.g., TempBond Clear, Kerr Corporation, Orange, CA)

27. TRY-IN AND CEMENTATION Try-in and bonding of tooth- coloured inlays or onlays are more demanding than those for cast gold restorations because of (1) the relatively fragile nature of some ceramic materials, (2) the requirement of near-perfect moisture control, and (3) the use of resin cements. Occlusal evaluation and adjustment generally are delayed until after the restoration is bonded, to avoid fracture of the ceramic material

28. PRELIMINARY STEPS The use of a rubber dam is strongly recommended to prevent moisture contamination of the conditioned tooth or restoration surfaces during cementation and to improve access and visibility during delivery of the restoration. After removing the provisional restoration, all of the temporary cement is cleaned from the preparation walls.

29. RESTORATION TRY-IN AND PROXIMAL CONTACT ADJUSTMENT Passing thin dental floss through the contact reveals tightness and position of the proximal contact, signifying to the experienced operator the degree and location of excess contact. Articulating paper also can be used successfully to identify overly tight proximal contacts. Abrasive disks or points are used to adjust the proximal contour and contact relationship. While adjusting the intensity and location of the proximal contacts, increasingly finer grits of abrasive instruments are used to polish the proximal surfaces because they will be inaccessible for polishing after cementation. Slight excesses of contour can be removed, if access allows, using fine-grit diamond instruments or 30-fluted carbide finishing burs. These adjustments are done preferably after the restoration is bonded so that marginal fractures are avoided. .

30. MECHANISM OF BONDING

31. Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12.

32. Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12. Ceramic restorations (with the exception of aluminous-core porcelains , such as In-Ceram High Strength Ceramic [Vita Zahnfabrik/Vident, Bäd Säckingen, Germany] and zirconia-core porcelain such as Lava [3M ESPE, St. Paul, Minn ]) must be etched internally with 6% to 10% hydrofluoric acid for 1 to 2 minutes to create retentive microporosities analogous to those that occur in enamel on etching with phosphoric acid. Hydrofluoric acid must be rinsed off carefully with running water for at least 2 minutes. Sandblasting with aluminum oxide particle can be done in the internal surface of the restoration. Mean bond strengths decrease, however, when hydrofluoric acid etching is not used.

33. Obradović-Đuričić K, Medić V, Dodić S, Gavrilov D, Antonijević Đ, Zrilić M. Dilemmas in zirconia bonding: A review. Srpski arhiv za celokupno lekarstvo . 2013;141(5-6):395-401 . The bonding of traditional glass-containing ceramics or silica based ceramics utilizes mechanical and adhesive way. Mechanical bonding assumed micromechanical interlocking between the resin cement and roughen surface of silica-based ceramics. Phosphoric acid or hydrofluoric acid etching is the method commonly used for roughening the silica-based ceramics surfaces. Chemical adhesion of glass ceramic and resin cements is achieved with use of bi-functional compounds, silanes that promote connection between dissimilar organic and inorganic counterparts. Also, silanes could influence increasing surface energy and wettabiliy of ceramic surfaces, which enhances both mechanical and chemical bonding

34. SUR F ACE PRE P ARA T ION G rind i ng Abrasion with diamond rotary instruments Airborne particle abrasion with aluminum oxide Acid etching with hydrofluoric acid or phosphoric acid or ammonium bifluoride Blatz MB, Sadan A, Kern M. Resin-ceramic bonding: a review of the literature. Journal of Prosthetic Dentistry. 2003 Mar 1;89(3):268-74.

35. Obradović-Đuričić K, Medić V, Dodić S, Gavrilov D, Antonijević Đ, Zrilić M. Dilemmas in zirconia bonding: A review. Srpski arhiv za celokupno lekarstvo . 2013;141(5-6):395-401 . The well known methods of mechanical and chemical bonding used on glass-ceramics are not applicable for use with zirconia. The most important reason for this is the absence of silica in the zirconia microstructure which ignores the viability of etching as a roughening method essential for mechanical bonding, as well as nullified the use of silanes, forming surfaces hydroxyls and developing the chemical bond

36. CEMENTATION

37. CEMENTATION

38. CEMENTATION

39. FINISHING AND POLISHING PROCEDURES

40. FELDSPATHIC PORCELAIN INLAYS AND ONLAYS

41. FELDSPATHIC PORCELAIN INLAYS AND ONLAYS

42. PRESSED GLASS-CERAMICS

43. PRESSED GLASS-CERAMICS

44. LITHIUM DISILICATE Lithium disilicate ( e.max , Ivoclar Vivadent Inc., Amherst, NY), is available in both pressed (IPS e.max Press) and machinable (IPS e.max CAD) forms, and either can be used to fabricate inlays and onlays. The two forms of e.max are slightly different in composition, but lithium disilicate is a moderately high-strength glass ceramic that also can be used for full crowns or ultra-thin veneers. In vitro testing of this ceramic material has shown very positive results, and it has become a highly popular alternative for inlays and onlays. However, because the material is relatively new, long-term clinical studies to demonstrate superior performance are lacking

45. COMPUTER-AIDED DESIGN/COMPUTER- ASSISTED MANUFACTURING INLAYS AND ONLAYS Generation of a chairside CAD/CAM restoration begins after the dentist prepares the tooth and uses a scanning device to collect information about the shape of the preparation and its relationship with the surrounding structures This step is termed optical impression. The system projects an image of the preparation and surrounding structures on a monitor, allowing the dentist or the auxiliary personnel to use the CAD portion of the system to design the restoration. The operator must input or confirm some of the restoration design such as the position of the gingival margins After the restoration has been designed, the computer directs a milling device (CAM portion of the system) that mills the restoration out of a block of high-quality ceramic or composite in minutes The restoration is removed from the milling device and is ready for try-in, any needed adjustment, bonding, and polishing

46. Several different types of ceramics are available for chairside CAD/CAM restoration fabrication. These include the feldspathic glass ceramics Vitablocs Mark II (Vident, Brea, CA) and CEREC Blocs (Sirona, manufactured by Vita Zahnfabrik, Bad Säckingen, Germany). The ceramic blocks are available in various shades and opacities, and some are even layered to mimic the relative opacity or translucency in different areas of a tooth. Two leucite-reinforced glass ceramics are available—IPS Empress CAD (Ivoclar Vivadent) and Paradigm C (3M ESPE). Lithium disilicate also is available in machinable form as IPS e.max CAD blocks. Although newer materials are stronger than the original ceramics, less is known about their long-term clinical performance

47. CERAMIC RECONSTRUCTION SYSTEM (CEREC-1) The Ceramic Reconstruction System (CEREC-1; Siemens, Germany) was the first commercially available CAD/CAM system used in dentistry. An intraoral video camera images the tooth preparation and the adjacent tooth surfaces. Features of the tooth preparation are used to define the limits of the restoration.

48. CERAMIC RECONSTRUCTION SYSTEM (CEREC-1) External surfaces of the restoration are estimated as distances to adjacent tooth structure in the computer view. Occlusal surfaces are designed from a pre-existing shape library and information about the occlusion. CEREC-3 displays an extremely high level of sophistication and can fabricate inlays, onlays, crowns, and veneers. It can be operated chairside, but also is being used with remote milling units in dental laboratories for two-appointment procedures. All other current CAD/CAM systems are employed in dental laboratories to fabricate a wide range of ceramic restorations

49. CEREC AC (A) and E4D (B) computer- aided design/ computer-assisted manufacturing (CAD/CAM) devices These chairside units are compact and mobile

50. COMMON PROBLEMS & SOLUTIONS The most common cause of failure of tooth-colored inlays/onlays is bulk fracture. Bulk fracture can result from placing the restoration in a tooth where it should not have been indicated, such as in bruxers and clenchers, or from lack of appropriate restoration thickness derived from lack of tooth preparation. If bulk fracture occurs, replacement of the restoration is almost always indicated.

51. REPAIR OF CERAMIC INLAYS AND ONLAYS Before initiating any repair procedure, the operator should determine whether replacement rather than repair is the appropriate treatment A small fracture resulting from occlusal trauma might indicate that some adjustment of the opposing occlusion is required. The repair procedure is initiated by mechanical roughening of the involved surface. Although a coarse diamond may be used, a better result is obtained with the use of air abrading or grit blasting with aluminum oxide particles and a special intraoral device

52. REPAIR OF CERAMIC INLAYS AND ONLAYS For ceramic restorations, the initial mechanical roughening is followed by brief (typically 2 minutes ) application of 10% hydrofluoric acid gel . Hydrofluoric acid etches the surface, creating further microdefects to facilitate mechanical bonding . The next step in the repair procedure is application of a silane coupling agent . Silanes mediate chemical bonding between ceramics and resins and may improve the predictability of resin-resin. After the silane has been applied, a resin adhesive is applied and light cured. A composite of the appropriate shade is placed, cured, contoured and polished

53. CONCLUSION Ceramic inlays offer an aesthetic alternative to metal class I or II restorations. Their primary use is in compromised posterior teeth with intact buccal and lingual walls. These restorations offer the opportunity to conserve tooth structure while taking advantage of the mechanical benefits of modern adhesive technology, which can strengthen the compromised tooth. Ceramic inlays offer a viable alternative to amalgam or cast-gold restorations, both of which have enjoyed long histories of clinical success.

54. REFERENCE Garber DA, Goldstein RE. Porcelain & composite inlays & onlays : esthetic posterior restorations. Chicago: Quintessence; 1994 Jan. Heymann HO, Swift Jr EJ, Ritter AV. Sturdevant's Art & Science of Operative Dentistry-E-Book. Elsevier Health Sciences; 2014 Mar 12 Freedman GA. Contemporary Esthetic Dentistry-E-Book. Elsevier Health Sciences; 2011 Dec 15 Hopp CD, Land MF. Considerations for ceramic inlays in posterior teeth: a review. Clinical, cosmetic and investigational dentistry. 2013;5:21 Thompson MC, Thompson KM, Swain M. The all‐ceramic, inlay supported fixed partial denture. Part 1. Ceramic inlay preparation design: a literature review. Australian dental journal. 2010 Jun 1;55(2):120-7. Obradović-Đuričić K, Medić V, Dodić S, Gavrilov D, Antonijević Đ, Zrilić M. Dilemmas in zirconia bonding: A review. Srpski arhiv za celokupno lekarstvo . 2013;141(5-6):395-401. Blatz MB, Sadan A, Kern M. Resin-ceramic bonding: a review of the literature. Journal of Prosthetic Dentistry. 2003 Mar 1;89(3):268-74.