Long-Term Observation of Post Copings Retaining Overdenture Prostheses.

Purpose: To investigate the long-term (up to 20 years) outcomes of customized post copings (PC) and to evaluate potential factors influencing the risk for complications.
Materials and Methods: Patients treated with PC-retained overdenture prostheses (OD) in a university setting were selected. Data collected included dental and periodontal parameters, periapical radiographs, and assessment of the OD design. Patient-reported satisfaction levels were evaluated using visual analog scales (VAS), and 20-year cumulative survival and success rates were calculated.
Results: A total of 73 patients with 81 ODs and 152 PCs were included. PC survival rate was 80.9%, and the success rate amounted to 64.5% after a mean observation period of 105.4 (± 67.9; range: 6 to 240) months. The 5-year cumulative PC rates were 91.5% for survival and 79.3% for success. Activation of matrices was more frequent with ball attachments than with cylindrical retention (odds ratio [OR] 0.43; 95% confidence interval [CI] 0.2 to 0.94; P = .034). Cylindrical retention was rated significantly better at 96% (interquartile range [IQR] 89.5% to 100%) compared to ball attachment at 88% (IQR 79% to 98.2%; P = .012). The risk for PC complications was higher for OD designs with coverage of the periodontal tissues compared to open designs (OR 0.34; 95% CI 0.15 to 0.78; P = .010).
Conclusion: Customized PCs on natural abutment teeth for the retention of ODs are a valid treatment in partially dentate patients. Correct prosthesis design and integration into a regular dental hygiene program are mandatory factors for long-term success.