Effect of the Time Interval of Functional Loading on the Periapical Healing of Endodontically Treated Mandibular Molar Teeth with Pulp Necrosis and Asymptomatic Apical Periodontitis: A Split-mouth Randomized Clinical Study.

Introduction: This prospective study evaluated the effect of immediate functional loading (IFL) of a full-coverage prosthesis on the clinical and radiographic outcome of nonsurgical endodontic therapy (NSET) performed on mandibular molar teeth with pulp necrosis and asymptomatic apical periodontitis.

Methods: In 20 subjects, standardized 2-visit NSET was performed in bilateral mandibular first molar teeth (split-mouth model) with a diagnosis of pulp necrosis and asymptomatic apical periodontitis exhibiting a radiographic periapical index (PAI) score ≥3. In each subject, the nonvital bilateral mandibular first molar teeth were randomized to 1 of 2 groups: the IFL group or the functional loading after a time interval of 6 months group. Provisional full-coverage prostheses were provided within 7 days after the completion of endodontic therapy. The cases were followed up clinically and radiographically at 6 and 12 months. Radiographs were assessed for periapical healing based on PAI scores, which were dichotomized as healed (PAI score ≤2) or nonhealed (PAI score ≥3). The data were compared using chi-square and Fisher exact tests.

Results: A recall rate of 100% was achieved at the end of 12 months. All teeth in the IFL group and the functional loading after a time interval of 6 months group were clinically asymptomatic. According to an intergroup comparison between the proportion of teeth healed and nonhealed (radiographic), there was a significant difference (P < .05).

Conclusions: IFL of a full-coverage prosthesis in endodontically treated mandibular molar teeth with pulp necrosis and asymptomatic apical periodontitis delayed periapical healing.