The Effect of Rubber Dam Usage on the Survival Rate of Teeth Receiving Initial Root Canal Treatment: A Nationwide Population-based Study

Introduction It is well-known that the usage of rubber dams during root canal treatment (RCT) improves infection control and treatment efficacy and protects patients. However, the effect of rubber dam usage on endodontic outcomes remain uncertain. The aim of the present study was to investigate whether rubber dam usage affects the survival rate of initial RCT using a nationwide population-based database. Methods A total of 517,234 teeth that received initial RCT between 2005 and 2011 met the inclusion criteria and were followed until the end of 2011. Univariate and multivariate Cox proportional hazards models were used to estimate the effects of rubber dam usage on the risk of tooth extraction after initial RCT. Results Of the 517,234 teeth, 29,219 were extracted, yielding a survival rate of 94.4%. The survival probability of initial RCT using rubber dams after 3.43 years (the mean observed time) was 90.3%, which was significantly greater than the 88.8% observed without the use of rubber dams (P < .0001). After adjusting for age, sex, tooth type, hospital level, tooth scaling frequency per year after RCT, and systemic diseases, including diabetes and hypertension, the tooth extraction hazard ratio for the RCT with rubber dams was significantly lower than that observed for RCT without rubber dams (hazard ratio = 0.81; 95% confidence interval, 0.79-0.84). Conclusions The use of a rubber dam during RCT could provide a significantly higher survival rate after initial RCT. This result supports that rubber dam usage improves the outcomes of endodontic treatments.