Contemporary endodontic retreatments: an analysis based on clinical treatment findings.

A prospective in vivo investigation was conducted to determine radiographic and clinical factors associated with contemporary nonsurgical endodontic retreatments. Approximately 1,100 failing endodontically treated teeth were screened to determine an appropriate treatment plan. Using magnification, 337 consecutive retreatment cases were evaluated and treated. The vast majority of the retreated cases involved multiple factors. Eighty-five percent of the cases presented with periradicular radiolucencies. Sixty-five percent of the cases demonstrated poor radiographic obturation quality. Associated pain was noted 51% of the time. Forty-two percent of the teeth had untreated canal space. It was statistically significant (Chi-square, p < or = 0.05) that additional canal space was located and treated in 89% of the cases that had previous radiographic asymmetrical obturations. Evidence of coronal leakage was noted in 13% of the retreated teeth. Tooth number, obturation materials, overfills, and previous surgical retrofillings were also recorded. Recommendations were made that might improve the rate of clinical success.