Clinical Outcomes of Endodontic Treatments and Restorations with and without Posts Up to 18 Years

Background: The aim of this study was to collect long-term restorative and endodontic outcomes of endodontically treated teeth (ETT). Methods: 298 teeth were included in the study and were recalled up to 18 years with a media of 10.2 years. At baseline, 198 sample teeth (66.44%) showed symptoms and 164 (55%) had periapical radiolucency. The most frequently used obturation techniques were warm gutta-percha in 80% of cases, and by carrier in 20%. A total of 192 ETT were restored by direct resin composite restorations, and 106 posts were luted. Moreover, 75 (25.16%) direct restorations remained as final restorations, 137 single crowns (45.97%), 42 (14.09%) partial adhesive crowns, and 42 (14.09%) abutments of fixed bridges were the final treatments. Descriptive and inferential statistics were performed (alpha = 0.05). A Cox regression model was made. Results: results showed success for 92.6% of ETT up to 18 years, 2.68% (8 ETT) showed irreversible failures, and 14 (4.69%) reversible complications. Four ETT (1.34%) failed because of root fracture and the other four (1.34%) because of endodontic complications. Eight ETT (2.69%) showed non-irreversible periodontal complications and the other six (2.01%) prosthodontic complications. Accordingly, with Kaplan-Meier analysis, the survival rate after 18 years was 97.3% (Interval of Confidence (IC) 95.1-98.3). The presence of a short or long (at least 1 mm related to radiographic apex) quality endodontic filling displayed a statistically significant higher risk of complication (hazard ratio (HR) = 17.00 (IC 5.68-56.84). Furthermore, a clinically detectable not precise coronal margins predicts the presence of any clinical complication with a hazard ratio almost seven times higher than endodontically treated teeth with a proper margin (HR = 6.89 (IC 2.03-23.38)), while the presence of lucency at the baseline did not affect the risk of complication (HR = 0.575 (IC 0.205-1.61)). The presence of post, tooth position in the arch, and the type of it did not show a high-risk rate (HR = 1.85, 1.98, and 2.24, respectively). Conclusions: a correct filling (at the apex) of root canals combined with proper coronal margins allow obtaining a long-term high success rate in teeth with a periapical lesion at the baseline. The use of a post or not, when its placement is related to the residual amount of the crown, does not change the final outcome of the ETT.

Automated summary

The study followed up on 298 endodontically treated teeth for long-term outcomes, with most teeth achieving success within 18 years. Proper root canal filling and precise coronal margins contribute to higher success rates, while the presence of a post does not significantly affect the final outcome.