UCLA

Statement of problem. Clinicians are regularly confronted with difficult choices. Should a tooth that has not healed through non-surgical root canal treatment be treated through traditional non-surgical retreatment, modern retreatment, or modern apical microsurgery? Acquiring complete, unbiased current information to help clinicians and their patients make these choices requires a systematic review of the literature on treatment outcomes, meta analyses and statistical comparisons.

Purpose. The purpose of this paper was to answer the following questions: What are the success rates of modern endodontic retreatment in teeth that had previously received NSRCT, where periradicular pathosis had not healed? Does modern endodontic retreatment result in increased healing rates over time? Does modern endodontic retreatment result in improved outcomes to those previously established for traditional retreatment? Does modern endodontic retreatment result in improved outcomes to those previously established for modern apical surgery?

Materials and methods. Searches were performed in Pubmed, Cochrane Library, and EMBASE databases on modern endodontic retreatment. Previously established datasets describing traditional endodontic retreatment and modern apical microsurgery were identified. Datasets were analyzed using funnel plots to examine bias, Forest plots to calculate weighted mean success rates and their associated confidence limits, and regression analysis to identify the simple linear equations relating percentage success rate to years of follow-up time.

Results. The quality of the papers reporting on modern endodontic retreatment was high and bias was low. The success rate for modern endodontic retreatment was largely unchanged through a period from 1 to 5 years of follow-up, a steady state was approximated. The success rate of modern endodontic retreatment was approximately 86% through 1 to 5 years after treatment. The success rate of modern endodontic retreatment was significantly higher than of traditional retreatment, 81%. The success rate of modern endodontic retreatment was equivalent to that of modern apical microsurgery, 85%.

Conclusions. Modern non-surgical endodontic retreatment should generally be the first-line treatment option after failure of initial non-surgical root canal treatment. Prospective, long-term modern retreatment studies of comprehensively described patient populations using a broad range of outcome measures are needed.