Long-Term Evaluation of Post Restorations: Results from a Practice-Based Study with up to 20 Years of Follow-Up.

Introduction This prospective, multicenter cohort study evaluated the long-term success and survival of endodontically treated teeth restored with posts (ETT+P) over 20 years and identified factors affecting their longevity.Methods A total of 195 ETT+P were treated by eight general dental practitioners, each placing up to 27 restorations. Post materials and dimensions were unrestricted, and only incisors, canines, and premolars were included. Success was defined as the post and definitive restoration remaining functional without clinical or radiographic failure, while survival required the post to remain in function regardless of reinterventions. Data were analyzed using multilevel Cox proportional hazards models to explore predictors of failure.Results Over a mean (95% Confidence Interval [95%CI]) follow-up period of 112 (97-127) months and a maximum of 20 years, 115 ETT+P achieved success (estimated success time: 145 (131-161) months), and 145 ETT+P survived (estimated survival time: 179 (165-193) months). The annual failure rates (AFRs) for success and survival were 5.4% and 3.2%, respectively. Recementation of pre-existing conventional and telescopic crowns significantly reduced both success (p