Porcelain fused to metal (PFM) crowns and caries in adjacent teeth.

OBJECTIVE To assess the discrepancies in marginal integrity and contact points of Porcelain Fused to Metal (PFM) crowns and its association with caries in adjacent teeth. STUDY DESIGN Cross-sectional study. PLACE AND DURATION OF STUDY Dental Section of the Aga Khan University Hospital, Karachi, from January to August 2009. METHODOLOGY Ninety six (96) patients with PFM crowns on maxillary and mandibular premolars and molars were included in this study. Single unit PFM crowns that were part of fixed bridge with at least one natural adjacent tooth were studied. PFM crown with no adjacent tooth or badly broken down teeth were excluded. Marginal integrity, contact points of PFM crowns and caries in adjacent teeth were assessed clinically and radiographically. The data was collected on a structured Proforma. Fisher's exact test was used for statistical analysis. RESULTS Marginal overhang and marginal gaps on the mesial surfaces of PFM crowns were observed in 17.7% and 13.5% respectively. Tight contact points and open contacts of PFM crowns with adjacent teeth were 15.6% and 17.8% respectively on mesial surfaces. Caries were present in 33.3% and 20% of teeth present mesial and distal to PFM crowns respectively. The association of faulty contact points of PFM crowns with caries in adjacent teeth was found significant (p < 0.001). The association of marginal discrepancy with caries in adjacent teeth was found significant (p = 0.002). CONCLUSION A significant association of faulty contact points and margins of PFM crowns with caries in adjacent teeth was found.