Date of Award
Master of Science (MS)
INTRODUCTION: The decision of which modality of secondary endodontic treatment to perform is multifactorial and clinician dependent. Literature surrounding the long-term survival of nonsurgical retreatment compared to root-end surgery remain equivocal and warrant further investigation. This 7-year retrospective study seeks to compare the outcome of nonsurgical retreatments with that of root-end surgeries performed on teeth without prior nonsurgical retreatments. METHODS: Insurance claims from 1021 teeth of 987 patients in the Delta Dental of Wisconsin database were analyzed from the years 2008–2017. Tooth survival was evaluated using Cox regression models and p-value was set at 0.05. Survival time was considered from the time of completion of nonsurgical retreatment or root-end surgery to time of an untoward event, defined as extraction after root-end surgery or extraction/root-end surgery after nonsurgical retreatment. Only procedures performed by endodontists were included in the analysis. RESULTS: The survival rate of teeth that received nonsurgical retreatment was 90% after 2 years, 86.8% after 4 years and 85% after 6 years. The survival rate of teeth that received root-end surgery was 93.7% after 2 years, 90.5% after 4 years and 88% after 6 years. No statistically significant difference was found in survival of nonsurgical retreatment compared to root-end surgery. Likewise, no statistically significant difference was found within or between tooth types (anterior, premolar, molar) when comparing nonsurgical retreatment to root-end surgery. CONCLUSION: The results of this study indicate that clinicians can choose either nonsurgical retreatment or root-end surgery after failed primary root canal therapy. Tooth location was not a determining factor in the survival rate after nonsurgical retreatment or root-end surgery.