Effect of adhesive resin cement on design of partial veneer crowns

Procedures involved in the tooth preparation, impression, and casting of partial veneer three-quarter crowns are considered to be complex.

This study assessed whether a simplified partial veneer crown design, when cemented with a 4-META adhesive resin, had a comparable resistance to displacement forces compared with a conventionally prepared partial veneer crown cemented with a traditional luting agent.

Conventional partial veneer crowns were prepared on 20 natural premolars, and 20 other premolars received modified partial veneer crown tooth preparations without proximal grooves. Artificial crowns were made for these teeth with Students alloy. Half the crowns in each of the 2 groups were luted with 4-META resin; the other half were luted with a zinc phosphate cement. Loads required to displace the partial veneer crowns were recorded after 24 hours and thermocycling, then the mode of separation was recorded for each crown. Average force required to displace partial veneer crowns for the 4 groups were subjected to 2-way analysis of variance and Scheffé test.

The 2 groups luted with 4-META resin and the group with proximal grooves luted with zinc phosphate were not significantly different. However, they were all greater than the group without proximal grooves luted with zinc phosphate cement.

Forces required to displace partial veneer crowns prepared in a traditional manner and those teeth prepared without proximal grooves were similar if the artificial crowns were luted with adhesive resin cement.