A Retrospective Study on the Success, Survival, and Incidence of Complications of Post-Retained Restorations in Premolars Supporting Fixed Dental Prostheses with a Mean of 7 Years in Function

Purpose: To evaluate the survival and success rates of post-and-core restorations supporting fixed dental prostheses (FDPs) after a mean time in function of 7 years and to assess the incidences of biologic and technical complications. Materials and Methods: Patients from the National Dental Center Singapore (NDCS) with endodontically treated premolars restored with post-retained FDPs from 2007 to 2009 were recruited from the Endodontic Registry and evaluated by three clinicians. A total of 265 patients with 329 treated premolars were examined clinically. Digital radiographs were also obtained. Complications were classified as tooth- or prosthesis-related. Failure and complication rates were calculated based on person-time-at-risk. Results: The mean time in function was 7.1 years. A total of 25 teeth in 23 patients were lost, resulting in a 7-year survival rate of 92.7% (95% CI: 89.5%, 95.0%). The corresponding success rate was 75.1% (95% CI: 70.5%, 79.1%). A total of 40 FDPs failed, resulting in a 7-year prosthetic survival rate of 88.6% (95% CI: 84.8%, 91.5%). Common complications observed were recurrent periodontal disease (3.9%), periapical pathology (7.3%), caries (3.9%), porcelain chipping (9.9%), and tooth fractures (5.0%). For the incidence of tooth fracture, a risk analysis yielded significant associations with the number of occluding teeth (odds ratio: 4.2; 95% CI: 1.1, 16.7) and the number of adjacent teeth (odds ratio: 4.0, 95% CI: 1.5, 10.9). Conclusion: Restoration of premolar teeth requiring root canal treatment with a post and core and crown is a viable treatment when premolar teeth have adjacent teeth.