Influence of Post Material and Cement Type on the Retention of Prefabricated Posts in Endodontically Treated Teeth

This in vitro study aimed to evaluate the effects of post material and cement type on the pull-out force of prefabricated glass-fiber, PEEK, and PEKK posts.

Sixty extracted human mandibular premolars were prepared with standardized root canals and allocated into six groups (n = 10) according to post material (glass-fiber, PEEK, PEKK) and luting cement (resin or glass ionomer). PEEK and PEKK posts were CAD-CAM fabricated from prefabricated discs. All specimens underwent thermocycling (6000 cycles, 5-55 °C) prior to pull-out force testing on a universal testing machine, and failure modes were classified as adhesive, cohesive, or mixed. Because variance homogeneity was not satisfied, pull-out force values were logarithmically transformed (Log10) before two-way ANOVA and Bonferroni-adjusted post hoc analyses.

Post material (p = 0.026), cement type (p < 0.001), and their interaction (p = 0.012) significantly influenced pull-out force. Under resin cement, no statistically significant differences were detected among glass-fiber, PEEK, and PEKK posts. Under glass ionomer cement, PEEK and PEKK posts demonstrated significantly higher pull-out force than glass-fiber posts. The highest mean pull-out force was observed for glass-fiber posts luted with resin cement. The effect of post material on pull-out force was dependent on the luting cement. PEEK posts luted with resin cement showed no significant difference in pull-out force compared with conventional glass-fiber posts, supporting their potential as an alternative post material. Further studies are needed to evaluate the clinical performance of PEEK posts.