Change in size of replaced amalgam restorations: a methodological study.

The purpose of this study was to evaluate the pre- and postoperative size of amalgam restorations that were scheduled for replacement. A video imaging system in combination with specially designed devices to align the stone casts prepared from impressions of the teeth gave reproducible results for both an in vitro and in vivo series. The in vivo series showed that removal of the occlusal part of amalgam restorations could be done without significantly increasing the size of the cavity in the tooth, provided the restorations did not have marginal discrepancies. If marginal discrepancies or recurrent caries were present, the replacement restorations showed a statistically significant increase in size compared with the original restorations.