Browsing by Author "Loguercio, Alessandro D."

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    Bleaching efficacy of in-office bleaching with violet light using low-concentration hydrogen peroxide nanoparticulate photocatalyst gel: A randomized controlled trial
    (Photodiagnosis and Photodynamic Therapy, 2024-11-23) Garcia Castro, Gustavo; Araújo Pinto, Palena; Favoreto, Michael Willian; Reis, Alessandra; Viviana-Mora, Maria; de Cássia Mendonça de Miranda, Rita; Milan Cardenas, Andres Felipe; Loguercio, Alessandro D.; de Jesus Tavarez, Rudys Rodolfo
    Objective This randomized controlled trial aimed to evaluate the bleaching efficacy and tooth sensitivity (TS) of participants submitted to different application protocols of in-office bleaching with violet light using 6 % hydrogen peroxide (HP) nanoparticulate photocatalyst gel. Materials and methods Sixty-six participants were randomized and bleached using either a 6 % HP (Nano White, DMC), and/or violet light (Bright Max Whitening, MMOptics), according to the following protocols: 1) only violet light (VIOL); 2) only bleaching gel application (BG) and; 3) combined bleaching gel application + violet light (BG+VIOL). The bleaching efficacy was evaluated with the Vita Easyshade spectrophotometer, Vita Classical and Vita Bleachedguide scales. The risk and intensity of TS were recorded using a 0–10 visual analogue scale (VAS) and a 0–4 numerical scale (NRS). Color change and intensity of TS values were compared using one-way ANOVA and Tukey's test were used. The absolute risk of TS was compared using the Chi-square test (α = 0.05). Results A significant and higher degree of bleaching was observed in the BG and BG+VIOL groups compared to the VIOL group (p < 0.003). Despite no significant differences in the risk (p > 0.07) and intensity (p > 0.28) of TS among groups, a higher risk of TS was observed in the BG and BG+VIOL groups. Conclusions Using VIOL reduced the risk of TS but did not improve bleaching. However, BG+VIOL with low-concentration HP nanoparticulate photocatalyst gel achieved equal efficacy and was less likely to cause TS compared to BG.
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    Clinical evaluation of a new chemically-cured bulk-fill composite in posterior restorations: 6-month multicenter double-blind randomized clinical trial
    (JOURNAL OF DENTISTRY, 2024-10-01) Loguercio, Alessandro D.; Carpio-Salvatierra, B; Ñaupari-Villasante, R; Wendlinger, M; Armas-Vega, Ana; Cavagnaro, S; León, A; Aliaga-Galvez, R; Gutiérrez, MF
    Objective To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months. Methods Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05). Results Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05). Conclusion Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service. Clinical significance The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch.
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    Do in vitro and in situ erosive challenges alter the bonding performance of universal adhesives?
    (International Journal of Adhesion and Adhesives, 2024-09-01) de Aguiar Moreira, Pedro Henrique; Wendlinger, Michel; de Faria Nonato, Rammon; Lincoln Calixto, Abraham; Binz-Ordonez, María Cristina; Figueredo de Siqueira, Fabiana Suelen; Loguercio, Alessandro D.; Millan Cardenas, Andres Felipe
    Objective To evaluate microtensile bond strengths (μTBS), nanoleakage (NL), and degree of conversion (DC) of two universal adhesives, using etch-and-rinse (ER) or self-etch (SE) strategies on eroded dentin submitted to in vitro and in situ erosive challenges. Methods Dentin blocks were prepared from 120 human molars and categorized based on dentin condition (sound, in vitro eroded, and in situ eroded), adhesive system (Scotchbond Universal [SBU] and Zip bond Universal [ZIP]), and adhesive strategy (ER and SE). In the in situ erosive challenge, 20 volunteers wore acrylic resin palatal devices with dentin blocks, immersing them in cola soft drink for 90 s, six times daily for 15 days. The same erosive protocol was used in vitro, followed by rinsing and remineralization. Sound dentin blocks served as controls. Afterward, all dentin blocks were restored with composite resin and sectioned into resin-dentin bonded sticks for μTBS, NL, and DC assessments. Data were analyzed using three-way ANOVA and Tukey's test (α = 0.05). Results Sound dentin exhibited the highest μTBS and DC values and the lowest NL values, while in situ eroded dentin showed the lowest μTBS and DC values and the highest NL values (p = 0.000001). While some differences in the μTBS values were observed between universal adhesives when evaluated on sound dentin (p = 0.0001), no significant differences between adhesives were observed when tested on in vitro and in situ eroded dentin. Regarding NL and DC, no significant differences were found between SBU and ZIP, as well as among adhesive strategies (p > 0.05). Conclusion Erosion in dentin, especially under in situ conditions, presents significant challenges to the adhesion of restorative materials. The choice of an effective adhesive system is crucial, as dentin eroded in situ showed lower adhesion strength and greater nanoleakage. These results highlight the need for specific clinical strategies to improve the durability and effectiveness of restorations.
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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.