Long-term survival of root-canal-treated teeth: a retrospective study over 10 years.

In this retrospective study the survival rate of 190 root-canal-treated teeth of 144 patients after 10-yr minimum was evaluated. Students during their training in 1987 and 1988 had performed the treatments. Age, gender, jaw, or quantity of root canals had no influence to the success of a root-canal treatment. Teeth with an apical lesion before the endodontic treatment showed a significantly shorter likelihood of survival. The best results could be found in root-canal fillings ending 0 to 1 mm and 1 to 2 mm before the apex. Comparing types of restoration, prosthetic-treated teeth with retention post and crown seem to be favorable. The study showed that root-canal treatment even conducted by students has a survival rate of 85.1% (Kaplan-Meier) after 10 yr and is a long-lasting, conservative therapy.