Browsing by Author "Favoreto, Michael William"

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    Effect of an experimental desensitizer with a hydroxyapatite-capsaicin composite applied before in-office dental bleaching on hydrogen peroxide diffusion, color and surface changes
    (Clinical Oral Investigations, 2024-11-27) Carpio-Salvatierra, Byron; da Silva, Karine Leticia; Favoreto, Michael William; González, Claudia; Rockenbach Binz Ordóñez, Maria Cristina; Loguercio, Alessandro D.; Farago, Paulo Vitor
    Objective To evaluate a prior application of an experimental desensitizer containing a hydroxyapatite-capsaicin composite (HAp-CAP) in different concentrations on hydrogen peroxide (HP) diffusion into the pulp chamber, bleaching efficacy (BE) and on physical and chemical alterations of the enamel surface after in-office bleaching. Materials and methods Forty sound premolars were randomized in five groups according to each experimental condition (n = 8): no bleaching (negative control), only bleaching (positive control), 0.1%, 1% and 5% of HAp-CAP. Four groups were submitted to in-office bleaching (HP 35%) post-desensitizer application. The HP concentration (µg/mL) on the pulp chamber was measured by UV-Vis spectrophotometer. The BE was measured by digital spectrophotometer (ΔEab, ΔE00 and ΔWID) before and after 7 days bleaching. Enamel tooth fragments obtained from twenty molars were submitted to the same experimental conditions and analyzed using FE-SEM and EDS, Vickers microhardness (VHN), Raman spectroscopy, and nanoroughness (Ra) by AFM to evaluate morphologic and chemical changes on enamel surface. All data were submitted to statistical analysis (α = 0.05). Results The groups treated with HAp-CAP exhibited a lower concentration of HP in the pulp chamber compared to only bleaching group (p < 0.05). There were no significant differences observed in BE between HAp-CAP groups and only bleaching group (p > 0.05). Only HAp-CAP 5% showed no significant differences in VHN values when compared to no bleaching group (p > 0.05). There were no significant differences among any group in Ra values (p > 0.05). The groups submitted to HAp-CAP showed a higher mineral concentration when compared to only bleaching group (p < 0.05). Conclusion Desensitizers containing HAp-CAP up to 5% effectively reduce HP diffusion into the pulp chamber after in-office bleaching, without interfering to BE and Ra, as well as prevent enamel demineralization. Clinical relevance The use of desensitizers containing HAp-CAP during in-office bleaching treatments offers a promising approach to reduce the risk of pulp irritation caused by hydrogen peroxide diffusion, without compromising the bleaching effectiveness or causing surface roughness.
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    Preparation and Characterization of a Novel Hydroxyapatite-Capsaicin Composite Intended for the In-Office Dental Bleaching Use
    (JOURNAL OF COMPOSITES SCIENCE, 2024-11-29) da Silva, Karine Letícia; Hortkoff, Diego; Favoreto, Michael William; Rezende, Marcia; Mendes Nadal, Jessica; Armas-Vega, Ana; Loguercio, Alessandro D.; Farago, Paulo Vitor
    The aim of this study was to synthetize a hydroxyapatite-capsaicin composite (HAp-CAP) and to evaluate its physicochemical data for further use in hydrogen peroxide in-office dental bleaching gel. The HApCAP was prepared by the precipitation method, performed in a 4:1 ratio using 3.2 g of nano-hydroxyapatite (nano-HAp) and 0.8 g of capsaicin (CAP) in 99.5% ethyl alcohol (q.s.p) and zirconia beads at SpeedMixer®. The HAp-CAP was characterized by morphological, spectroscopic, and thermal analyses. In the following, the HAp-CAP was added to an in-office dental bleaching to test its effect on reducing hydrogen peroxide diffusion into the pulp chamber, as well as the effect in the color alteration during dental bleaching. The HAp-CAP were suitably obtained by the precipitation method, and the results demonstrates that the thermal stability of the CAP is greatly improved after reaction of HAp and CAP. The HAp-CAP into a bleaching gel slightly decreased the amount of hydrogen peroxide inside the pulp chamber and didn’t interfering in the bleaching effectiveness of dental bleaching. The HAp-CAP synthesis and characterization were successfully carried out, and its use in dental materials is a challenging task that needs further study since its addition.