Polishing Amalgam Restorations

Author: Boban Fidanoski

Rationale for polishing amalgam restorations


1. Improved gingival health

2. Improved biocompatibility of amalgam

3. Increased integrity of junction of tooth surface and restoration

4. Improved maintenance by client (easier plaque removal with tooth brushing and flossing)

5. Increased length of service of the restoration


Contraindications for polishing amalgam restorations

inishing and polishing procedures should not be initiated on an amalgam restoration until the amalgam has reached its final set, at least 24 hours after it has been placed and carved. Premature finishing and polishing will interfere with the crystalline structure of the hardening amalgam. The result will be a weakened restoration. Studies have been conducted on polishing high copper amalgams ten minutes after placement; however, it is presently recommended that at least 24 hours pass before the polishing procedure is attempted.


Single restorations may be polished at the next recall appointment. Multiple restorations should be polished at a specific polish appointment. An amalgam restoration is not considered complete until it is polished.



Precautions required when polishing amalgam restorations


A. Precautions:


1. Maintain functional anatomy by using the instruments in the correct manner.
-Start all rotary instruments prior to touching the restoration.

-Keep instruments moving over the surface.

-Use short overlapping strokes to minimize friction.

-Use each instrument only on the surfaces for which it was designed.

-Be aware of the four surface changes that can be inflicted upon a restoration while finishing and polishing that will destroy it:

a. Flattening cusps excessively.

b. Reducing marginal ridges below the plane of occlusion.

c. Removing the contact.

d. Deeply ditching or grooving the restoration.

- Cups and points wear quickly from use and autoclaving. And exposed metal shank will scratch the amalgam surface.

2. Avoid improper contouring by understanding the proper tooth anatomy that must be achieved.

3. Prevent damage to the client’s soft tissue.

- Retract the tongue, cheeks and lips during the procedure

- Position instruments correctly so they will not abrade the soft tissue.

- Use a secure grasp and stable fulcrum with each instrument.

- Rinse all abrasive materials from the mouth after polishing.

4. Protect the client from polishing debris (aerosols are frequently created when polishing with pumice and tin oxide)

- Remove excess abrasive material from the mouth as quickly as possible.

- Provide eye protection for the client.

- Do not carry instruments or abrasive materials over the client's face.

5. Protect the pulp of the tooth from excess heat.

- Use air or water cooling streams whenever possible.
Use abrasive agents that are wet rather than dry. They can be mixed with water or alcohol to help lubricate and cool the agents.

- Run rotary instruments at the minimum speed that will still be effective.

- Use intermittent contact of the rotary instruments to the tooth surface.



Characteristics of a well polished amalgam restorations


1. Smooth anatomic surfaces

2. Intact contact areas

3. Correctly spaced embrasures

4. Refined margins

5. Smooth resistant surfaces

6. Functional effectiveness

7. Acceptable appearance

8. No plaque-retaining irregularities

9. Restored health of the gingival tissues




author: Boban Fidanoski

© February, 2007 Copyright - Text
by B.Fidanoski- Port Credit, ON - Canada