A prospective clinical trial comparing preformed metal crowns and cast restorations for defective first permanent molars

Abstract

Aim: This study investigated two methods for the restoration of permanent molars affected by amelogenesis imperfecta (AI) or severe enamel defects.

Methods: A prospective clinical trial was carried out on 17 subjects affected by AI or severe enamel defects of first permanent molars. A split mouth design was used so that each right or left permanent molar in both jaws was restored using either a preformed metal crown (SSC) or a cast adhesive coping (CAC). Subjects were followed for up to 24 months and assessed for longevity and quality of the restorations. Sequential analysis was used to compare longevity.

Results: Records for 42 restorations (19 SSC; 23 CAC) were kept. The split mouth design was possible on 24 occasions (right versus left=14; maxilla versus mandible=10). Three restorations, one SSC (at 6 months) and two CAC (at 2 and 19 months) failed and required replacement. There was no significant statistical difference between the two types of restorations.

Conclusion: While there was no difference between the two restorations for quality and longevity, the SSC was considerably cheaper to use and needed only one visit, but more tooth tissue was lost in preparation and fitting. The CAC was significantly more expensive but left nearly all of the tooth crown intact. The choice of which restoration to use is indicated by the immediate and long-term needs of each individual patient.