Endodontic infection: some biologic and treatment factors associated with outcome

Abstract

Objective: We sought to investigate the simultaneous effect of apical periodontitis, instrumentation level, and density of root canal filling on endodontic treatment outcome.

Methods: For this study, 200 endodontically treated teeth with 441 roots were used. A follow-up examination was conducted 4 +/- 0.5 years postoperatively. Data were subjected to univariate and multivariate analysis.

Results: Periapical pathosis had the strongest effect on treatment outcome (P <.0001). The instrumentation level (mean +/- SEM of the working length) for successfully treated teeth/roots with normal preoperative pulp and periapex was farther away from the radiographic apex (1.23 +/- 0.13 mm) than for teeth/roots with an unsuccessful outcome (0.20 +/- 0.09 mm; P <.005). However, successfully treated teeth/roots with pulp necrosis and apical periodontitis had working length levels closer to the radiographic apex (0.55 +/- 0.12 mm) than did teeth/roots with unsuccessful outcomes (1.73 +/- 0.30 mm; P<.001). In teeth/roots with apical periodontitis, a millimeter loss in working length increased the chance of treatment failure by 14%. The risk of failure was higher for a fair/poor density of obturation than for a good density for all diagnoses of periradicular status.

Conclusion: Diseased periapex, level of working length relative to the radiographic apex, and fair/poor density all affect the outcome of endodontic treatment.