A statistical analysis of surgical and nonsurgical endodontic retreatment cases.

A total of 1300 endodontic patient charts were analyzed for factors that may have contributed to the failure of the original treatment or the success of the retreatment. Of those surveyed, 667 had recall information of 6 months or more and were used to consider success rates. The remaining cases were analyzed for other information. The findings were tabulated and analyzed by computer for significant relationships. The overall success rate for retreatment was 65.6% with an additional category of "uncertain" of 18.3%. Surgical treatment was necessary to retreat 53.5% of the cases.