BDS11173 Indirect Esthetic Restorations

Course Title

• BDS11173 Indirect Esthetic Restorations

Course Aim

• Detail different types of indirect esthetic restorations, their indications, and materials used.
• Explain selecting the best restoration and preparing the tooth to receive it.
• Explain bonding indirect esthetic restorations.

Course Objectives

• Understanding the diverse indirect esthetic restorations and their indications.
• Understanding the steps and process in indirect esthetic restorations, including tooth preparation.

Outline

• Limitations of direct esthetic restorations and indications of indirect restorations.
• Materials and techniques of fabrication.
• Material selection.
• Advantages of indirect restorations.
• Indications of indirect restorations.
• Cavity preparation.
• IDS & DME.
• Impression techniques.
• Provisionalization and try-in.
• Cementation.
• Finishing and polishing.

Limitations of Direct Esthetic Restorations

• Marginal fracture.
• Inadequate bond.
• Shrinkage.
• Marginal adaptation.
• Shrinkage stress.

Indirect Esthetic Restorations

• Fabricated outside the patient's mouth.
• Made on a replica of the prepared tooth.
• Created in a lab or using CAD/CAM.

Indirect Esthetic Restorations: Popularity

• Driven by patient demand for aesthetics, durable restorative materials.
• Improvements in materials, fabrication techniques, adhesives, and resin-based cements.

Indirect Esthetic Materials and Fabrication Techniques

• Ceramics (feldspathic porcelain, castable ceramics, hot-pressed ceramics, infiltrated ceramics, machined ceramics).
• Hybrid Ceramic.
• Resin Composite. -CAD/CAM (Laboratory, flexi models, 3D printing)

Material Selection

• Modules of elasticity and surface luster and wear to the opposing and wear resistance.

Advantages of Indirect Restorations

• Higher physical and mechanical properties.
• Variety of materials and techniques.
• Wear resistance.
• Reduced polymerization shrinkage.
• Support of remaining tooth structure.
• More precise control of contours and contacts.
• Increased auxiliary support.
• Biocompatibility and good tissue response.

Indications of Indirect Restorations

• Lesion size, etiology, and number of involved surfaces.
• Number of teeth affected.
• Patient compliance, habits, and preferences.
• Dentist's competence.

Decision-Making Process: Direct vs. Indirect

• Category A: Direct restorations are suitable.
• Category B: Uncertainty over the best approach.
• Category C: Indirect restorations are better.

Additional Indirect Restoration Indications

• Replacement of large compromised existing restorations.
• Contour and occlusal contact ease of development.
• Endodontically treated posterior teeth where cuspal protection is needed.

Modifying Factors

• Inability to maintain a dry field. This impacts long-term success.
• Occlusion and para-functional habits (bruxing, clenching).
• Deep subgingival preparations (not an absolute contraindication but generally avoided).

Cavity Preparation

• Check occlusion.
• Field isolation.
• Tools.
• General criteria.
• Cusp reduction.
• Finish line.
• Recent modifications.
• Patient anesthetization
• Area isolation with rubber dam.
• Amalgam or exposure removal.
• Removal of caries.
• Using different tools.

Tools for Tooth Preparation

• Tapered diamond burs for occlusally divergent facial and lingual walls.
• Rounded-end cutting instruments.
• Finishing diamonds.

Anatomically Driven Preparation

• Maintains favorable stress distribution.
• Improves adhesion.
• Minimizes dentin exposure which supports hard tissue preservation
• Optimizes esthetic integration.
• Preparation design to be adequate thickness.
• Rounded internal angles.
• Well-defined margins.
• Facial and lingual extensions.
• Smooth curves around cusps.

Margins

• 90-degree butt-joint cavity surface angle (for strength).
• Avoid beveling.
• Surface increased for bonding with glass based materials.
• Gingival-occlusal divergence of >2-5 degrees per wall .

Resistance and Retention

• Resistance of the tooth structure.
• More surface area for bonding.
• Lateral displacement prevention and undercut blocking.

Pulpal Floor and Isthmus

• Smooth and relatively flat.
• Isthmus needs a minimum 2mm.
• Smooth transition for strength.
• 2mm deep for cusps.

Capping Cusps

• Shoulder preparation.
• Prevent accidental contact with opposite tooth.

Immediate Dentin Sealing (IDS)

• Better adhesive properties of freshly cut dentin.
• Less intra- and post-operative hypersensitivity.
• Better bond strength to dentin.
• Two-step adhesive or universal adhesive covered with flowable composite.
• Glycerin coverage during photopolymerization.

Deep Margin Elevation (DME)

• Placing the gingival margin of the restoration for cementation ease, better impressions, restoration seating, and excess removal.
• Usable composites are flowable, bulk fill, injectable.

Impression

• Conventional method.
• Digitization of conventional model.
• Digital method.

Fabrication

• Ceramics.
• Hybrid ceramics.
• Resin composite.
• CAD/CAM(lab, flexi, 3D printing).

Provisionalization

• Stabilizes both occlusal and proximal contacts.
• Protects soft tissue.
• Materials include light-cured temporary filling.
• Additional option is 3D printed restoration.

Try-in

• Checking the fit, and proximal contact.
• Assessing adaptation of margins.
• Materials including Wax, PMMA, or final materials.

Cementation

• Cement material selection.
• Tooth surface treatment.
• Fitting surface treatment.
• Light curing.
• Excess removal and polishing.

Resin Cement vs. Composite

• Comparison between resin cement and heated flowable composites.

Resin Cement

• Dual cure vs. light cure: (restoration thickness, translucency, and aesthetics.)
• Conventional vs. self-adhesive.

Tooth Surface Treatment and Cementation

• Material specific treatments based on structure and materials.
• Use of etching, primers, and adhesives.
• Acidity considerations.

Bonding of Silica Based Restorations

• Hydrofluoric acid: etches the internal surfaces.
• Acid-etching: enhances surface area for micromechanical bonding.
• Bonding generally done in office or lab.

Bonding to Tooth Structure

• Tooth surface refreshment using Alumina is key.
• Selective etching technique / self-etching technique.

Finishing and Polishing

• The use of 30-fluted carbide finishing burs for smoothing interproximal surfaces.
• Using a scalpel blade to eliminate resin cement.
• Polishing ceramic restorations using abrasive techniques.

Occlusal Adjustment and Re-polishing

• Occlusal adjustment tools and techniques.

Finishing Processes

• Smoothing with rubber abrasive points/cups.
• Diamond polishing using paste and tools.

Flexible Model Technique

• Fast-setting vinyl polysiloxane injection.
• Setting time.
• Dye separation.
• Silicon cast creation.
• Layer build up with different shades and curing.

Additional Information

• Reading materials are presented for further study. 

This quiz covers various types of indirect esthetic restorations, their indications, and the materials used. It also focuses on the processes involved in selecting and preparing a tooth for these restorations. Additionally, the quiz addresses bonding techniques and other essential aspects of indirect restorations.