BDS11173 Indirect Esthetic Restorations PDF

BDS11173 Indirect Esthetic Restorations Aim: o To detail different types of indirect esthetic restorations, their indications and the materials used. o To explain how to select the optimal restoration and prepare tooth to receive it. o To explain how to bond indirect esthetic restorations...

BDS11173 Indirect Esthetic Restorations Aim: o To detail different types of indirect esthetic restorations, their indications and the materials used. o To explain how to select the optimal restoration and prepare tooth to receive it. o To explain how to bond indirect esthetic restorations. Objectives On completion of this lecture, the student should have: o An understanding of the wide variety of indirect esthetic restorations and their indications o An understanding of the steps and process involved in indirect esthetic restorations, including teeth preparations to receive these restorations The outline 1- limitations of direct restorations &indications of indirect restorations. 2- materials and techniques of fabrication. 3- material selection. 4- advantages of indirect restorations. 5- indications of indirect restorations. 6- cavity preparation. 7- IDS & DME. 8- impression techniques. 9- provisionalization &try- in. 10- cementation. 11- finishing and polishing. 1-Limitation of direct esthetic restorations Relationships between Flexural and Bonding Properties, Marginal Adaptation, and Polymerization Shrinkage in Flowable Composite Restorations for Dental Application  Indirect esthetic restorations Are restorations fabricated outside the patient’s mouth. Indirect restorations are made on a replica of the prepared tooth in a dental laboratory or by using computer-aided design/computer-assisted manufacturing (CAD/CAM) either chairside or in the dental laboratory.  Indirect esthetic restorations Esthetic inlays, onlays and overlays have become popular not only because of patient demand for esthetic, durable restorative materials but also because of improvements in materials, fabrication techniques, adhesives, and resin-based cements. 2- materials and techniques of fabrication. Indirect Esthetic materials Resin Ceramics Hybrid Composite Ceramic -CAD/CAM -CAD/CAM -CAD/CAM -Laboratory -Laboratory -Flexi model -3D printing Among the ceramic materials used ▪ Feldspathic porcelain. ▪ Castable ceramics ▪ Hot pressed ceramics ▪ Infiltrated ceramics ▪ Machined ceramics 3-Material selection MODULES OF SURFACE LUSTER WEAR TO THE OPPOSING WEAR RESISTANCE ELASTICITY & POLISHABILITY 4-Advantages of indirect restorations 1. Higher physical and mechanical properties. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 4. Reduced polymerization shrinkage. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 4. Reduced polymerization shrinkage. 5. Support of remaining tooth structure. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 4. Reduced polymerization shrinkage. 5. Support of remaining tooth structure. 6. More precise control of contours and contacts. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 4. Reduced polymerization shrinkage. 5. Support of remaining tooth structure. 6. More precise control of contours and contacts. 7. Increased auxiliary support. 1. Higher physical and mechanical properties. 2. Variety of materials and techniques. 3. Wear resistance. 4. Reduced polymerization shrinkage. 5. Support of remaining tooth structure. 6. More precise control of contours and contacts. 7. Increased auxiliary support. 8. Biocompatibility and good tissue response. 5- indications of indirect restoration Most clinical decisions regarding the most appropriate choice of restorative material and technique are dictated by: Direc Lesion size, etiology & no of involved surfaces. Number of teeth affected. Patient compliance, habits and preferences. The dentist’s own competence and skills. The decision-making process involved when choosing to use either a direct or an indirect approach for any given clinical situation can be categorized as: - Category A: direct restorations clearly indicated - Category B: uncertainty over which is the most appropriate approach - Category C: indirect restorations clearly indicated Direct or indirect restorations?, Smithson et al, INTERNATIONAL DENTISTRY – AFRICAN EDITION VOL. 1, NO. 1 The decision-making process involved when choosing to use either a direct or an indirect approach for any given clinical situation can be categorized as: - Category A: direct restorations clearly indicated - Category B: uncertainty over which is the most appropriate approach - Category C: indirect restorations clearly indicated Direct or indirect restorations?, Smithson et al, INTERNATIONAL DENTISTRY – AFRICAN EDITION VOL. 1, NO. 1 The decision-making process involved when choosing to use either a direct or an indirect approach for any given clinical situation can be categorized as: - Category A: direct restorations clearly indicated - Category B: uncertainty over which is the most appropriate approach - Category C: indirect restorations clearly indicated The decision-making process involved when choosing to use either a direct or an indirect approach for any given clinical situation can be categorized as: - Category A: direct restorations clearly indicated - Category B: uncertainty over which is the most appropriate approach - Category C: indirect restorations clearly indicated Direct or indirect restorations?, Smithson et al, INTERNATIONAL DENTISTRY – AFRICAN EDITION VOL. 1, NO. 1 Replacement of large compromised existing restorations.  The contours and the occlusal contact of large restorations are more easily developed using indirect techniques. Endodontically treated posterior tooth were cuspal protection is required. Modifying factors Inability to maintain a dry field: any adhesive technique require near-perfect moisture control to ensure successful long-term clinical results. Modifying factors Occlusion and para-functional habits Ceramic restorations can fracture when they lack sufficient thickness as in patients who have bruxing or clenching habits. Modifying factors Deep subgingival preparations: This is not an absolute contraindication but preparations with deep subgingival margins generally should be avoided why ? 6- cavity preparation Check occlusion Field isolation Tools General criteria Cusp reduction Finish line Recent modification  The patient should be anesthetized. The area is isolated with rubber dam preferentially (amalgam/exposure). The compromised restoration if present is completely removed and all the caries is excavated. Tools A tapered diamond should be used for tooth preparation to creates occlusally divergent facial and lingual walls. the cutting e nd of the instrument should have a rounded design to avoid creating sharp, stress-inducing internal angles in the preparation. Finishing diamond (red coded ) to finish the enamel margins and cavity walls Anatomically driven preparation should be applied to maintain favorable stress distribution all over the Tooth/Restoration complex. Benefits: 1- improve adhesion(why) 2- minimize dentine exposure(why) 3- maximize hard tissue preservation 4- optimize esthetic integration  Preparations are designed to provide adequate thickness(not less than 2) for the restorative material with rounded internal angles and well-defined margins to avoid stress concentrations in the restoration and tooth. The facial and lingual walls should be extended to sound tooth structure and should go around the cusps in smooth curves.  All margins should have a 90-degree butt-joint cavosurface angle to ensure marginal strength of the restoration. Beveling of the margins creates weak porcelain margins and should be avoided. Beveling can be performed for esthetic concerns and more surface area for bonding in case of glass based reinforced ceramic restorations. Gingival– occlusal divergence of the preparation should be greater than the 2 to 5 degrees per wall which allows for passive insertion and removal of the restoration.  Resistance of tooth restoration complex is gained by providing enough thickness of the restorative material and protecting the weakened tooth structure. Retention of the restoration is gained by providing more surface area for bonding specially good rim of sound enamel beside axial walls to avoid lateral displacing forces. Undercuts can be blocked out with a flowable composite for the sake of conservation of remaining tooth structure.  The pulpal floor should be smooth and relatively flat. Most ceramic systems require that any isthmus be at least 2 mm wide with smooth transition among different parts of the preparation to decrease the possibility of fracture of the restoration. In cusp coverage step, the occlusal portion of the preparation should be 2 mm deep. Many failures of ceramic inlays and onlays can be attributed to insufficient thickness.  When capping cusps, it might be necessary to prepare a shoulder to move the facial or lingual cavo-surface margin away from any possible contact with the opposing tooth. Contacts directly on margins can lead to premature deterioration of marginal integrity. 7-Immediate Dentin Sealing IDS - Freshly cut dentin shows better adhesive properties - IDS provides less intra and post operative hypersensitivity - IDS shows better bond strength to dentin substrate - Should be performed using two-step filled self-etch adhesive or universal adhesive covered by flowable composite. - IDS should be covered with glycerin during photopolymerization to avoid the effect of oxygen inhibited layer on the impression taking. 7-Deep Margin Elevation DME - Placement of the gingival margin of the restoration in a level to facilitate - Isolation process during cementation - Better impression taking wither conventional or digital - Better restoration fabrication and seating - Easiness of excess cement removal - Can be performed using - Flowable composite - Bulk fill flowable composite - Injectable composite 8-Impression Digitization of conventional conventional Digital model Fabrication Indirect Esthetic materials Resin Ceramics Hybrid Composite Ceramic -CAD/CAM -CAD/CAM -CAD/CAM -Laboratory -Laboratory -Flexi model -3D PRINTING 9- Provisonalization -the aim of this step is to provide stabilization for both occlusal and proximal contact until the delivery of the final restoration and provide protection for the soft tissue. - Materials used :1- light cured temporary filling 2- 3D printed restoration 9- Try- in To check the fit, proximal contact and the adaptation of the margins before proceeding to the final restoration. Materials: Wax PMMA Final material  11-cementation - Cementation material - Tooth surface treatment - Fitting surface treatment - Light curing - Excess removal and polishing Resin cement vs composite (flowable - heated) Resin cement -Dual cure vs Light cure (restoration thickness, translucency and esthetics) - Conventional vs self-adhesive - Cementation material - Tooth surface treatment (according to cementation material and predominant tooth structure substrate) - Fitting surface treatment - Light curing - Excess removal and polishing - Cementation material - Tooth surface treatment - Fitting surface treatment (glass based ceramics vs hybrid ceramics vs composite) - Light curing - Excess removal and polishing  Bonding of silica based HF acid is used to etch the internal surfaces of the restoration. Acid-etching increases the surface area and results in micromechanical bonding of the composite cement to the ceramic restoration. HF etching generally is done in office or by the laboratory. A. Hydrofluoric acid: dissolve the surface and expose the silica crystals in the matrix. B. Silane coupling agent: form a chemical covalent bond between the silica in the ceramic matrix and copolymerize with the methacrylate groups through siloxane bonds.  Bonding To Tooth structure Refreshment of the tooth surface using Alumina particle size >30 microns at pressure>5 bar. The prepared tooth structure is either treated by selective etching technique or by self etching technique according to the adhesive system used with the resin cement. - Cementation material - Tooth surface treatment - Fitting surface treatment (glass based ceramics vs hybrid ceramics vs composite) - Light curing (tack cure, all direction full cure) - Excess removal and polishing - Cementation material - Tooth surface treatment - Fitting surface treatment (glass based ceramics vs hybrid ceramics vs composite) - Light curing (tack cure, all direction full cure) - Excess removal and polishing (after tack curing- sharp blade- excesso)  11-Finishing & Polishing Procedures 30-fluted carbide finishing burs can be used to obtain a smoother finish Interproximally. A scalpel blade can be used to remove excess resin cement when access permits. Ceramic restorations can be polished to be as smooth as glazed porcelain using the abrasive sequence. 11- occlusal adjustment & re- polishing Occlusal adjustment (tools and technique) Polishing( why)  Further smoothing is accomplished with a series of rubber abrasive points and cups used at slow speed with air-water spray. Final polishing of the ceramic restoration may be achieved by applying a diamond polishing paste with a bristle brush or another suitable instrument.  The Flexible Model Technique Chair side A fast setting vinyl polysiloxane is injected into the impression. Left to set for few minutes. Dyes are separated with a scalper.  The Flexible Model Technique Chair side By this way a silicon cast is obtained within a few minutes. The restoration is built up using different shades, each layer is light cured. Finishing Cementation polishing Advances in ceramic, polymer, and adhesive technologies have resulted in the development of a variety of tooth-colored indirect Class I and II restorations. Because the clinical procedures are relatively technique-sensitive, however, proper case selection, operator skill, and attention to detail are crucial to success. Reading materials: ▪ Essentials of esthetic dentistry, principles and practice of esthetic dentistry, volume one, 2015. Nairn H. F. Wilson. ▪ Comprehensive esthetic dentistry, 2015. Florin Lazarescu. ▪ Esthetic and restorative dentistry, materials selection and technique, third edition, 2018. Douglas A. Terry and Willi Geller. ▪ Tooth whitening in esthetic dentistry, So-Ran Kwon and Seon-Hook Ko. ▪ Esthetic dentistry, a clinical approach to techniques and materials, second edition, 2001. Ascheim Dale. Aim: o To detail different types of indirect esthetic restorations, their indications and the materials used. o To explain how to select the optimal restoration and prepare tooth to receive it. o To explain how to bond indirect esthetic restorations. Objectives On completion of this lecture, the student should have: o An understanding of the wide variety of indirect esthetic restorations and their indications o An understanding of the steps and process involved in indirect esthetic restorations, including teeth preparations to receive these restorations Towards unbounde d thinking.