Durability of a polyacid-modified composite resin (compomer) in primary molars. A multicenter study.

A polyacid-modified composite resin (compomer) restorative material was evaluated in primary molars in a multicenter study. One hundred and fifty-nine class-II restorations were placed by 6 dentists in 79 children. The restorations were evaluated during a 2-year period, using slightly modified USPHS criteria. After 1 year 151 restorations were evaluated and, after 2 years, 104. The cumulative failure rate after 1 year was 8% and after 2 years, 22%. The main reasons for failure were loss of retention (12%) and secondary caries (5%). The compomer material showed a high failure rate, comparable to that of other adhesive restorative materials currently used in primary molars. A large operator variation in failure rate indicates the technique sensitivity of the material.