Factors influencing the success of conventional root canal therapy--a five-year retrospective study.

This retrospective study on the outcome of conventional root canal therapy was carried out on patients attending the Eastman Dental Hospital between 1970 and 1982. A minimum follow-up period of 5 years was required for patients to be included in the survey. The characteristics of the resulting sample group, the techniques for canal preparation and obturation and the obturating materials used were analysed. The type of obturating material used had no demonstrable effect on success rate but sex, age, preoperative vitality and periapical pathology were associated with significantly differing success rates. Technique also influenced success rate; the method of canal preparation and the position of the apical seal relative to the radiographic apex were both found to be significant. The overall success rate was 84.29%, representing 692 of 821 teeth included in the survey.