Finishing Cast Restorations Presentation

Finishing the Cast Restoration

• The presentation is about finishing cast restorations.
• The presenter, Dr. Adham Nyazi, and Dr. Malak Bamigdad, are associated with Batterjee Medical College.
• The presentation outlines objectives and procedures for finishing different zones of the cast restoration.

Armamentarium

• The presentation lists materials required for finishing.
• These include carbide burs, diamond burs, stone and rubber burs/wheels, carborundum disks, finishing disks, Al2O3 particles, and sandpaper, and measuring gauges.

Introduction

• After the investment process, the unpolished restoration needs finishing before cementation.
• The sprue must be removed, and the attachment area polished.
• Sequential procedures are used for finishing the cast restoration, divided into zones.
• A smoother wax pattern results in a smoother casting.

Zone 1: Internal Margin

• Objective: Minimize the dissolution of the cement, creating a 1 mm wide metal band fitted to the tooth.
• Procedure: Use a small carbide bur (1/4 round), examine nodules, and correct any defects in the marginal zone. Remake if defects are present.

Zone 2: Intaglio

• Objective: Achieve no contact between the die and intaglio surface, with a uniform space of 25-35 microns for the luting agent.
• Procedure: Use a 1/4 or 1/2 round carbide bur. Perform an examination for nodules, and carefully seat the die. If the die is abraded, redo the impression, or re-wax if necessary.

Marking Agents

• Marking agents are used to highlight areas to be worked on.
• These include water-soluble dies (Liqua-Mark), solvent-based dies (AccuFilm IV), powdered sprays (Occlude), Rouge and elastomeric detection paste (Fit Checker).

Zone 3: The Sprue

• Objective: Re-establish the proper coronal structure and function by re-contouring the attachment area.
• Procedure: Utilize a carborundum separating disk to cut the sprue. Avoid using wire cutters. Refine the area using stones and sandpaper disks.

Zone 4: Proximal Contacts

• Objective: Correct proximal contacts in the patient's mouth, either ensuring proper tightness or preventing looseness.
• Procedure: Examine proximal contacts on the stone model. Use a scalpel to slightly relieve any inappropriate contacts. Evaluate and polish connectors. Use mylar articulating film to examine multiple castings individually.

Zone 5: Occlusal Surface

• Objective: Achieves static and dynamic occlusion.
• Procedure: Use mylar articulating film to identify high points. Use flame shaped diamond burs or stone burs. Use a measuring gauge. Polish the surface with a soft brush and rouge (5 microns) or airborne particular abrasion (25-50 micron AL2O3, 20 microns).

Zone 6: Axial Walls

• Objective: Allowing the patient to maintain proper plaque control.
• Procedure: Use a stone bur and rubber wheel with abrasive particles for polishing using a sequence of abrasives. Maintain proper light pressure for finishing vs. polishing.

Zone 7: External Margins

• Objective: Create a highly polished surface for better plaque control.
• Procedure: Best polished on the tooth. Focus on difficult proximal and subgingival areas. Pay attention to marginal fit and emergence profile.

This presentation by Dr. Adham Nyazi and Dr. Malak Bamigdad covers the essential objectives and procedures for finishing cast restorations. It also details the necessary tools and materials, along with the step-by-step process required to achieve a polished result before cementation. Gain insights into specific zones of finishing techniques and the importance of a smooth wax pattern.