Randomized controlled trial comparing glass fiber posts and cast metal posts

Objective: This study aimed to assess the survival and success of glass fiber posts compared to cast metal posts in teeth without ferrule.

Material and methods: An equivalency, prospective, double-blind (patient and outcome evaluator) randomized controlled trial (RCT) with parallel groups was designed to compare the clinical performance of cast metal and glass fiber posts cemented in endodontically treated teeth without ferrule (NCT01461239). Teeth were randomly allocated to the glass fiber or cast-metal post groups. All teeth were restored with single metal-ceramic crowns. Kaplan-Meier analysis with the log-rank test was used to test the success and survival between glass fiber and cast metal posts considering a cut-off value of P = 0.05. The annual failure rates were calculated considering the survival data for all restorations and separated by type of post after five years.

Results: A hundred and nineteen patients and 183 posts (72 cast metal posts and 111 glass fiber posts) were analyzed. The median follow-up was 62 months (IQR 37-81). The log-rank test for success (P = 0.26) and survival (P = 0.63) analyses did not present statistically significant differences. The AFR of both posts after 5 years was 1.5%. Considering the posts separately and after 5 years, cast metal posts presented AFR of 1.2% and glass fiber posts AFR of 1.7%. Most failures were in posterior teeth (16/23), 10 failures were classified as root fractures and 5 as post debonding. The follow-up rate was 95.3%.

Conclusions: Glass fiber and cast metal posts showed good and similar clinical performance.

Clinical significance: Results of this randomized controlled trial can help dentists to answer how the best technique to rehabilitate endodontically treated teeth with no remaining coronal wall.