Biomimetic-analog Aqueous Solution and One-bottle Phosphate-based Adhesive Preserves Aentin uTBS

Objectives: Determine short-term resin-dentin interface uTBS and chemical analys of an aquous solution containing biomimetic analogs associated with an experimental one-bottle etch-and-rinse adhesive system (E&R) containing bioactive calcium-phosphates.
Methods: The experimental materials consisted of a aqueous-HEMA solution with and without biomimetic analogs (distilled water, HEMA, polyacrylic acid and polyvinylphosphonic acid) and solvated one-bottle E&R adhesive system (HEMA, UDMA, TEGDMA, BisEMA, BisGMA, ethanol, photoinitiator) with and without bioactive phosphates (ß tricalcium phosphate and monocalcium phosphate mono-hydrated). Thirty extracted human molars were sectioned into 4 dentin quarters and ramdomly assigned to the following groups: G1: no analogs nor phosphates, G2: no analogs + phophates, G3: analogs+no phosphates and G4: analogs+ phosphates. After acid etching (15s), rinsing, and application of solution/adhesive combinations, 5 mm composite blocks were build up on dentin. Sections on x and y directions were done to obtain beams (0.75 mm x 0.75 mm). Samples were stored for 24h and 4-months (4m) before µTBS test. Failure mode was classified as adhesive, cohesive or mixed. Representative beams of each group were prepared for Ca/P analysis with energy dispersive X-ray spectrometry (EDX). The µTBS and EDX data were analyzed using 2-way ANOVA and Tukey’s test (p<0.05).
Results: There was no statistical difference in 24h dentin uTBS (p>0.05). Application of aquous solution with analogs (G3 and G4) promoted stable µTBS over 4M storage (p>0.05). For all groups, the most common failure pattern observed was adhesive (24h or 4M). EDX analysis presented Ca/P stabilization for G1 and G4 (24h and 4M); for G2 and G3 resin-dentin interface was less soluble after 4M.
Conclusions: The application of an aquous solution contatining biomimetic analogues in acid etched dentin along with an adhesive containing biomimetic phosphates maintained 4M dentin µTBS and stabilized the resin-dentin interface Ca/P proportion.