The effect of two luting agents, pretreatment of the post, and pretreatment of the canal dentin on the retention of fiber-reinforced composite posts

Objectives The purposes of this study were to evaluate the push-out strength of core-build-up resin used for fiber-post cementation and to test the effects of different post and dentin pretreatment for different regions of the root. Methods After endodontic treatment 216 human teeth received a glass-fiber post. The teeth were divided into test groups to simulate the effects of: (I) cementation material (specifically core-build-up resin or conventional luting cement), (II) pretreatment of the root dentin (none, dual-curing bonding, light-curing bonding), (III) pretreatment of the post (none, hydrofluoric acid, tribochemical pretreatment), and (IV) different regions of the root. After thermal cycling all post-cemented roots were sectioned and each specimen was loaded in a universal testing machine until failure occurred. Statistical analysis was performed by use of a mixed-effects regression model. Results The cementation material (p ≤ 0.001), the pretreatment of the post (p ≤ 0.001), and the bonding of the root dentin (p ≤ 0.001) had a significant effect on mean push-out strength. Statistical analysis also revealed a significant effect of root region (p ≤ 0.001)—values were lower for the apical region than for the coronal third of the root. Conclusions Enhanced retention can be achieved by use of a core-build-up resin for fiber-post cementation. Tribochemical pretreatment of the post and use of a dual-curing bonding system also increased mean push-out strength.