Influence of dentin pretreatment with synthetic hydroxyapatite application on the bond strength of fiber posts luted with 10-methacryloyloxydecyl dihydrogen phosphate-containing luting systems

The aim of this in vitro study was evaluate the effect of application of synthetic hydroxyapatite on fiber post bond strength to radicular dentine. Forty, single-root teeth were endodontically treated and an 8 mm post space was prepared. Specimens were randomly placed in four groups (n = 10 in each) and treated using the following fiber post luting procedures: group 1, 17% EDTA + Panavia SA; group 2, 17% EDTA + Teethmate Desensitizer + Panavia SA; group 3, All-Bond Universal + Duo-Link Universal; and group 4, All-Bond Universal + Teethmate Desensitizer + Duo-Link Universal. Fiber posts were luted in the post space and light-cured for 120 s using a light-emitting diode (LED) lamp. After 7 d of storage at 37°C, the teeth were cut into 1-mm-thick slices, which were subjected to a push-out test until failure using a universal testing machine. Two specimens per group were prepared for scanning electron microscopy analysis. An energy-dispersive X-ray spectroscopy detector was used for elemental analysis of the specimen surface. The results were statistically analyzed using one-way anova. The fiber post bond strength was statistically significantly increased after the application of Teethmate Desensitizer to post space walls, either with a 10-MDP-containing self-adhesive cement or with a universal adhesive. Scanning electron microscopy and EDAX analysis showed that Teethmate Desensitizer created a calcium phosphate precipitate over post space dentinal tubules, which significantly improved the bond strength of the fiber post luted with 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing adhesive systems.