The relationship between restoration and furcation involvement on molar teeth.

The purpose of this cross-sectional study was to examine the correlation between the presence of a crown (CR) or a proximal restoration (RE) and furcation involvement (FI) on molar teeth. Data were collected from 134 periodontal maintenance patients who had restored and non-restored molars present both with and without FI. A majority of the restorations that were present in these patients had been in place for at least 5 years prior to the study. First and second molars were examined clinically using the following criteria: CR, RE, FI, mobility (MO), and probing periodontal attachment level (AL). Data were analyzed with a statistical program utilizing Pearson chi-square and the pair-difference t test. The results indicated that molars with CR or RE had a significantly (P < 0.01) higher percentage of FI but no greater mobility when compared to molars without restorations. Mean probing periodontal attachment loss was greater for restored than non-restored molars but only with marginal significance (P = 0.051). There was a greater difference in mean AL between restored versus non-restored maxillary molars than for mandibular molars. This cross-sectional study provides evidence that molars with crowns or restorations involving the proximal tooth surfaces had a higher prevalence of FI and greater AL than molars without restorations.