Preparation and Characterization of a Novel Hydroxyapatite-Capsaicin Composite Intended for the In-Office Dental Bleaching Use

The objective of this research was to synthetize a hydroxyapatite-capsaicin composite (HAp-CAP) and assess its physicochemical properties for potential use in an in-office dental bleaching gel. The HAp-CAP nanocomposite was prepared by the precipitation method using a 4:1 ratio of nano-hydroxyapatite (nano-HAp) to capsaicin (CAP) dissolved in 99.5% ethyl alcohol (q.s.p) with the assistance of zirconia beads in a SpeedMixer®. Characterization of HAp-CAP involved morphological, spectroscopic, and thermal analyses. Subsequently, HAp-CAP was incorporated into an in-office dental bleaching agent to evaluate its impact on reducing hydrogen peroxide diffusion into the pulp chamber and its effect on tooth color alteration during the bleaching process. The HAp-CAP in a bleaching gel slightly decreased the amount of hydrogen peroxide inside the pulp chamber and did not interfere in the bleaching effectiveness of dental bleaching. The physicochemical characterization indicates that the synthesis process of the HAp-CAP composite was successfully carried out, and its use in dental materials poses a challenging task that warrants further investigation since its incorporation.