Adaptation of resin facings to cast gold alloy restorations in the mouth

Abstract

The occurrence of marginal spaces between the resin facing and gold alloy framewark in 176 crowns and bridge retainers was studied. The restorations were made for canine teeth. The assessment of spaces at the cervical alloy-resin junction was carried out by examining slides of the buccal surfaces taken after application of disclosing agent. Spaces at the incisal alloy-resin junction were assessed by examining resin models under the stereomicroscope. Randomly selected restorations were grouped and examined with reference to length of clinical service (1, 3, 6, and 9 years). The methods were tested for reliability and consistency. The results showed that the frequency of cervical spaces tended to increase with length of clinical service, whereas the frequency of the incisal spaces seemed to remain unchanged. The most severely worn facings had the highest frequency of cervical spaces. In contrast, the least worn facings seemed to have the highest frequency of incisal spaces. For both the cervical and the incisal spaces the highest frequencies were found for relatively long resin facings. □ Resin facing adaptation; resin-veneered cast restorations