Furcation involvement and tooth loss: A registry-based retrospective cohort study.

AIM: This registry-based retrospective cohort study aimed to evaluate the impact of furcation status on the risk for molar loss. MATERIALS AND METHODS: Subjects with and without furcation involvement (FI) in 2010/2011 were identified in a nationwide registry in Sweden (age- and gender-matched sample: 381,450 subjects; 2,374,883 molars). Data on dental and periodontal status were extracted for the subsequent 10-year period. Impact of FI (at baseline or detected during follow-up) on molar loss (i.e., tooth extraction) was evaluated through multilevel logistic regression and survival analyses. RESULTS: FI had a significant impact on molar loss. FI degrees 2 and 3 resulted in adjusted risk ratios of 1.67 (95% confidence interval [CI] 1.63-1.71) and 3.30 (95% CI 3.18-3.43), respectively. Following the first detection of deep FI (degrees 2-3), estimated survival decreased by 4% at 5 years and 8% at 10 years. In addition to FI, endodontic status and probing depth were relevant risk factors for molar loss. CONCLUSIONS: Furcation status had a clinically relevant impact on the risk for molar loss. Following first detection of deep FI, however, the decline in molar survival was minor.