Long-term success and survival of post-endodontic restorations without posts after up to 18 years: A practice-based study.

Objectives The aim of this non-interventional, multi-center, prospective, practice-based study was, firstly, to evaluate the longevity of composite build-ups in endodontically treated teeth, treated with root canal therapy (ETT), without post placement and secondly, to identify and analyze factors influencing the success of these reconstructions. Methods Each of seven general dental practitioners placed up to 50 composite build-ups without additional posts in ETT. Teeth were restricted to incisors, canines and premolars. Clinical data (i.e. type of build-up restoration (material, adhesive); type of final restoration (material, adhesive)) were recorded for 192 coronal restorations on ETT in 192 patients. Cox proportional hazards models were applied to analyze associations between clinical factors and time until failure. Results Within a follow-up period of up to 18 years (mean(95 %CI): 102 (90-113) months, max:217 months) 155 restorations (81 %) were judged as successful [mean success time: 176 (165-187) months] and 164 teeth (85 %) survived [mean survival time: 187 (178-197) months]. The main failure type was fracture of the restoration (n = 16). The annual failure rate was 2.4 % and 1.7 %, respectively. In bivariate Cox regression the factors 'dentist' and 'adhesive' were significantly associated with failure rate (p ≤ 0.017). However, in multivariate Cox proportional hazards regression none of the investigated factors were significantly associated with failure rate (p ≥ 0.089). Conclusion For composite build-ups in ETT without post placement high success rates could be found after up to 18 years of observation. Within the limitations of the present study none of the analyzed factors such as 'dentist' or 'adhesive was a significant predictor for the failure rate. Clinical Relevance Endodontically treated teeth, treated with root canal therapy, can be successfully directly restored with composite build-ups even when no additional post is inserted. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012882).