This guide provides a comprehensive overview of the steps and best practices for adjustment and cementation of metal (alloy) restorations.
Adjustment recommendations
Instruct the patient to bite on carbon paper lightly for initial modifications. After the first adjustment, ask the patient to bite firmly and follow a complete excursion movement pattern, then proceed with the final adjustments.
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Tools for Shaping:
- A fine-grit diamond
- Football-shaped bur for occlusal and lingual surfaces, especially anterior teeth.
- Tapered bur for buccal and lingual surfaces.
- High-Speed Handpiece: Use a high-speed handpiece with minimal pressure, employing water and air spray to maintain temperature and prevent micro-fractures.
Note: Air-only handpiece adjustments are not recommended.
Metal (Alloy) Restoration Cementation Steps
Adhering to these steps and recommendations will ensure effective and durable cementation of metal restorations.
- Note: Always consult the manufacturer’s instructions for specific guidelines.
Step 1 - Surface Preparation
- Metal crowns require air abrasion with alumina particles for enhanced adhesion.
Step 2 - Restoration Preparation
- Clean restorations post-try-in to remove contaminants like saliva.
- Techniques include sandblasting with aluminum oxide and using zirconia cleaning solutions or hydrofluoric acid.
Step 3 - Tooth Pretreatment
- After removing the temporary, clean the tooth with pumice paste to eliminate residues.
Step 4 - Cement Application and Crown Seating
- Use primers and cement with methacryloyloxydecyl dihydrogen phosphate (MDP).
- Seat the crown with firm pressure after dispensing cement into it.
Step 5 - Excess Cement Removal
- After allowing the cement to be set for the recommended duration by the manufacturer, carefully clean any surplus cement without disturbing the placement of the crown.