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Aim: To analyse the influence of H2O2 on pulp repair through osteocalcin and osteopontin immunolabelling and in cellular defence by using the antireactive oxygen species (ROS) antibody. Methodology: The maxillary molars of 50 rats were treated with 35% H2O2 (Ble groups) or placebo gel (control groups). At 0 h and 2, 7, 15 and 30 days (n = 10 hemimaxillae), the rats were killed and pulp tissue was evaluated using inflammation and immunolabelling scores (osteocalcin/osteopontin); ROS‐positive cells were counted. Paired t‐test and Wilcoxon signed‐rank test were used (P < 0.05). Results: The Ble group had necrosis in the coronal pulp at 0 h and in the occlusal third of the coronal pulp at 2 days; at 7, 15 and 30 days, no inflammation was noted similar to the controls (P > 0.05). Osteocalcin was absent in the Ble at 0 h, moderate at 2 days and increased thereafter, differing from the controls at all two periods (P < 0.05). Osteopontin was higher principally at 7 and 15 days in Ble groups, but differing with control groups from 2 days after bleaching (P < 0.05). The Ble group had more ROS‐positive cells in the pulp at 7 and 15 days (P < 0.05). Tertiary dentine was observed at 7 days, increasing thereafter (P < 0.05). Conclusions: Post‐bleaching pulp repair was associated with increased osteocalcin over time. Osteopontin also participated in this process, and anti‐ROS was involved in cellular defence against H2O2. [ABSTRACT FROM AUTHOR]

Aim: To investigate the effect of chronic alcohol consumption on apical periodontitis in rats. Methodology: Thirty‐two male Wistar rats were arranged into four groups: Control (C): without apical periodontitis and nonalcoholic diet; (AL): without apical periodontitis and alcoholic diet; (AP): with apical periodontitis and nonalcoholic diet; and (AP + AL): with apical periodontitis and alcoholic diet. The alcoholic solution at 20% was given to the AL and AP + AL groups as the sole source of hydration throughout the experiment. AP was induced in the mandibular left first molars at the end of the 4th week. Weight changes and the amount of solid and liquid foods were recorded for 8 weeks. At the end, the animals were euthanized and the jaws removed followed by histological processing for histopathological and RANKL, OPG, TRAP and HIF‐1α analyses. The Mann–Whitney test was used for nonparametric data, and anova followed by the Tukey test was performed for parametric data, with P < 0.05. Results: Animals that received the alcoholic diet had a lower weight gain than the other groups (P < 0.05). Control and AL groups did not have an inflammatory response in the periapical tissues. The median score of inflammatory infiltrate was significantly higher in the AP + AL group (2.5) compared to the AP group (1.5; P < 0.05). In the same comparison, AP + AL was associated with score 3 for RANKL and HIF‐1α versus score 2 for AP group (P < 0.05). Moreover, the values for TRAP were 3.88 ± 0.70 cells mm−1 for the AP + AL group and 2.43 ± 0.94 cells mm−1 for the AP group (P < 0.05). Conclusion: In rats, an alcoholic diet had a significant effect on the severity of apical periodontitis, exacerbating the inflammatory response and osteoclastogenesis. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To investigate whether hypertension affects mineralization associated with white and grey mineral trioxide aggregate (MTA Angelus®) implanted subcutaneously into rats by assaying osteoblastic biomarkers. Methodology: Polyethylene tubes containing grey MTA Angelus®, white MTA Angelus®, intermediate restorative material (IRM; positive control) or an empty tube (negative control) were implanted into the dorsal connective tissue of spontaneous hypertensive (n = 12) and Wistar (normotensive; n = 10) rats. Half of the rats in each group were killed after 7 days, and the remaining after 30 days. Tubes with surrounding tissue were removed, and immunostaining was performed to detect RUNX‐2, OPN and OCN proteins. The normality of data was analysed using the Shapiro–Wilk test. Comparison of two independent groups was performed using the Mann–Whitney U‐test, to detect a significant difference. A post hoc test accounting for multiple comparisons was performed following Tukey's test (P < 0.05). Results: Under hypertensive conditions after 30 days, both MTA materials were associated with immunolabelling for RUNX‐2 from low to moderate, which was less than that observed at normal blood pressure and the 7‐day groups (P < 0.05). The expression of OPN and OCN proteins under both MTA conditions was considered low after both 7 and 30 days for the hypertensive condition, and was less than that in animals with normal blood pressure after 30 days (P < 0.05). No immunostaining for any biomarkers in the control and IRM groups was observed (P < 0.05). Conclusion: Hypertension decreased the immunostaining of RUNX‐2, OPN and OCN biomarkers in response to MTA. Thus, hypertension can jeopardize the mineralization ability of MTA and may have a negative impact on endodontic treatment outcomes. [ABSTRACT FROM AUTHOR]

Background: Dental whitening with peroxides has been popularized through the at-home technique, which employs low concentrations of peroxide applied in individual trays. However, there are few clinical trials reporting the effects of its continuous use on oral microbiota. Thus, the purpose of the present clinical, randomized study was to evaluate the influence of at-home whitening treatment on Streptococcus mutans in saliva, buccal mucosa, and subgingival and supragingival plaque.Methods: Thirty volunteers were randomly divided into two study groups (N = 15) according to the whitening therapy: G CP, whitening using 10% carbamide peroxide 4 h daily for 21 days; and G HP, whitening using 6% hydrogen peroxide 1.5 h daily for 21 days. Samples from the predetermined locations were collected at three evaluation periods: T1, before; T2, immediately after; and T3, 30 days after the beginning of the treatment. The microbiological evaluation was made using conventional and molecular methods.Results: Student's t-test demonstrated a statistically significant decrease in S. mutans population in the subgingival and supragingival plaque for HP samples between T1 and T2 no difference was found between T1 and T3 regardless of the location and the whitening product used (α = 0.05).Conclusions: Although HP reduced S. mutans during treatment, the levels returned to baseline when assessed 30 days after the treatment. [ABSTRACT FROM AUTHOR]

Aim To evaluate pulpal tissue response after dental bleaching in normal and alloxan-induced diabetic rats. Methodology Twenty-eight rats were divided into two groups of normoglycaemic and diabetic rats ( n = 14). Diabetes mellitus ( DM) was induced with alloxan. After DM confirmation, all rats were anaesthetized and dental bleaching was performed with 35% hydrogen peroxide (H2O2) on the right maxillary molars for 30 min. Left molars were used as controls. Bleaching resulted in four hemimaxillae groups: normoglycaemic (N), N-bleached ( NBle), diabetic (D) and D-bleached ( DBle). After 2 or 30 days, the animals were euthanized and the hemimaxillae were removed, processed for histopathological analysis and stained with haematoxylin-eosin ( HE), Masson's trichrome ( MT) and picrosirius red ( PSR). Results obtained within animals (normoglycaemic or diabetic rats) were submitted to Wilcoxon or paired t-tests, and between animal (normoglycaemic and diabetic rats), to Mann-Whitney test or t-tests. Results At 2 days, the NBle group had a mild inflammatory infiltration in the pulpal tissue, whilst the DBle had severe inflammation or necrosis ( P < 0.05). At 30 days, no inflammation was present. However, a significant difference in pulp chamber area reduction by reactionary dentine deposition was found between the NBle and DBle groups ( P < 0.05). At 2 days, fewer immature collagen fibres and more mature collagen fibres were noted in the NBle, D and DBle groups; this was significantly different when compared to the N group ( P < 0.05). At 30 days, significantly fewer immature collagen fibres and more mature collagen fibres were noted in NBle compared with DBle group ( P < 0.05). Conclusions The inflammatory tissue response in rats' teeth after dental bleaching was greater in diabetic rats. Additionally, the increase in reactionary dentine deposition and mature collagen fibres observed in diabetic rats needs further evaluation to confirm the present results. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of acid etching of the enamel and the combination of different light sources (halogen light, light-emitting diodes [LEDs], and LED/Laser) and the bleaching product on color change, penetration of hydrogen peroxide (H2O2), and cytotoxicity over time. The color change (AE) and the amount of H2O2 that permeated the tooth tissue were analyzed using a spectrophotome-ter. Cell metabolism and morphology were evaluated using the methylthiazol tetrazolium assay and scanning electron microscopy, respectively. The AE values and H2O2 permeation were not significantly different under any of the experimental conditions. Tooth whitening significantly reduced cell metabolism, regardless of whether a light source was used. Preconditioning the enamel did not influence the cellular metabolism in any group. In conclusion, combining the bleaching product with different light sources and/or preconditioning the enamel resulted in few significant changes in color, transenamel and transdentinal penetration of H2O2, or cytotoxicity and cell morphology. [ABSTRACT FROM AUTHOR]

Aim To measure glycosylated haemoglobin ( Hb A1c) in a diabetic model as a means of investigating apical periodontitis and periodontal disease for their effects on both blood glucose concentrations and long-term glycaemic control. Methodology Wistar rats ( n = 80) were assigned to one of eight groups (10 animals/group): control ( G1), apical periodontitis ( G2), periodontal disease ( G3), apical periodontitis and periodontal disease ( G4), diabetic ( G5), diabetic with apical periodontitis ( G6), diabetic with periodontal disease ( G7) and diabetic with apical periodontitis and periodontal disease ( G8). A diabetic state was induced with streptozotocin. Apical periodontitis was induced by dental exposure to the oral environment. Periodontal disease was induced by periodontal ligature. Blood glucose concentrations were measured at 0, 6, 30 and 60 days. After euthanization, rat maxillae were excised and processed for histopathology and for measurement of Hb A1c levels by ion exchange chromatography. Data were tabulated and subject to statistical analysis ( P < 0.05). Results The inflammatory infiltrate and alveolar bone resorption were more severe in diabetic rats ( P < 0.05). Diabetic rats exhibited higher levels of Hb A1c independent of apical periodontitis or periodontal disease ( P < 0.05). However, the presence of oral infections in diabetic rats was associated with increased blood glucose concentrations ( P < 0.05). Conclusions Oral infections affect glycaemic conditions in diabetic rats and increase Hb A1c levels in normoglycaemic or diabetic rats. [ABSTRACT FROM AUTHOR]

Purpose: To compare the color alteration, surface roughness and microhardness and cross-sectional microhardness of bovine enamel treated with at-home whitening strips and gels., Materials and Methods: Sixty-six pigmented specimens (n = 11) were allocated to six groups: C-cotton wool moistened with distilled water for 1 h; SDS-sodium dithionite strip, for 1 h; HPS-6.5% hydrogen peroxide strip, for 1 h; CPS-20% carbamide peroxide strip, for 1 h; HPG-7.5% hydrogen peroxide gel, for 1 h; CPG-10% carbamide peroxide gel, for 4 h. The treatments lasted 10 days, calculating the ∆E, ∆E 00 , and ∆W ID at baseline, 5 and 10 days, and 14 days after completion. Additional 66 polished discs (n = 11) were used to analyze the surface roughness and microhardness of enamel before and after bleaching, cross-sectional microhardness and integrated mineral loss (ΔZ; %Vol × μm). Data were subjected to statistical analysis by two-way Anova RM and Tukey post-test (α = 0.05)., Results: In ∆E and ∆W ID analysis, greater values were obtained in CPG (p < 0.001), followed by HPG and HPS (p = 0.271). SDS and CPS (p < 0.001) exceeded only C (p < 0.001). In ∆E 00 , at completion of treatments, the results were similar; however, HPG = HPS = CPS (p = 0.237). There was an increase in roughness and decrease in surface microhardness in all bleaching groups (p < 0.005). Concerning the cross-sectional microhardness, the treatments were equal to C at 150 μm, the last depth analyzed. For ΔZ, the values of SDS, CPS, HPG, and CPG groups showed similar mineral loss (p > 0.001), and the lowest value was exhibited in the Control group, followed by HPS group (p < 0.001)., Conclusion: Although the strips were aesthetically effective, the CPG and HPG groups presented highest values in the ∆E 00 and ∆W ID analysis. However, all treatments influenced the enamel surface, increasing roughness and decreasing surface and transverse microhardness., Clinical Relevance: The whitening gels promoted greater chromatic changes, but all treatments affected the enamel surface, increasing roughness and decreasing surface and transverse microhardness., (© 2025 Wiley Periodicals LLC.)

Background: Photodynamic therapy (PDT) has shown satisfactory antibacterial effects. However, little information regarding the cytotoxicity potential of PDT using curcumin as a photosensitizer (PS) on fibroblasts are found. The aim of this in vitro study was to evaluate the cytotoxicity of root canal irrigating solutions and photodynamic therapy with curcumin PS on the L-929 cell line., Methods: Healthy mouse skin fibroblast cells were distributed into the following 7 experimental groups: G1 - culture medium DMEM (control group); G2 - 0.9% sodium chloride; G3 - 2.5% sodium hypochlorite (NaOCl); G4 - 5% NaOCl; G5 - PDT with curcumin PS at 500 mg/L + blue LED; G6 - PDT with curcumin PS at 750 mg/L + blue LED; and G7 - PDT with curcumin PS at 1000 mg/L + blue LED. All experimental groups which underwent PDT action were submitted to blue LED for 4 min, with a wavelength of 480 nm and energy fluency of 75 J/cm². The cultures were maintained under standard cell culture conditions (37°C, 100% humidity, 5% CO 2 ). Cell viability analysis was performed using the colorimetric method to evaluate the periods of 6, 24, and 48 h. Data were subjected to the Kruskal-Wallis test, followed by the Dunn test to compare groups and Friedman test to compare periods (α = 0.05)., Results: When comparing the periods, no significant differences were observed for any of the experimental groups analyzed (p > 0.05), except for the NaOCl 2.5 group that exhibited higher cell viability at 6 h compared to the period of 48 h (p = 0.0489). In the comparisons of the experimental groups, there were no statistically significant differences between the control group compared to all disinfection protocols, regardless of the period evaluated (p > 0.05), except for the PDT + C 1000 group that showed lower cell viability (P < 0.05)., Conclusions: PDT with curcumin at 1000 mg/L was cytotoxic on L-929 fibroblast cell culture. However, laser-activated curcumin at a concentration of 500 mg/L presented no influence on L-929 fibroblast cell viability in in vitro conditions., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The development of biomaterials based on the combination of biopolymers with bioactive compounds to develop delivery systems capable of modulating dentin regeneration mediated by resident cells is the goal of current biology-based strategies for regenerative dentistry. In this article, the bioactive potential of a simvastatin (SV)-releasing chitosan-calcium-hydroxide (CH-Ca) scaffold was assessed. After the incorporation of SV into CH-Ca, characterization of the scaffold was performed. Dental pulp cells (DPCs) were seeded onto scaffolds for the assessment of cytocompatibility, and odontoblastic differentiation was evaluated in a microenvironment surrounded by dentin. Thereafter, the cell-free scaffold was adapted to dentin discs positioned in artificial pulp chambers in direct contact with a 3-dimensional (3D) culture of DPCs, and the system was sealed to simulate internal pressure at 20 cm/H 2 O. In vivo experiments with cell-free scaffolds were performed in rats' calvaria defects. Fourier-transform infrared spectroscopy spectra proved incorporation of Ca and SV into the scaffold structure. Ca and SV were released upon immersion in a neutral environment. Viable DPCs were able to spread and proliferate on the scaffold over 14 d. Odontoblastic differentiation occurred in the DPC/scaffold constructs in contact with dentin, in which SV supplementation promoted odontoblastic marker overexpression and enhanced mineralized matrix deposition. The chemoattractant potential of the CH-Ca scaffold was improved by SV, with numerous viable and dentin sialoprotein-positive cells from the 3D culture being observed on its surface. Cells at 3D culture featured increased gene expression of odontoblastic markers in contact with the SV-enriched CH-Ca scaffold. CH-Ca-SV led to intense mineralization in vivo, presenting mineralization foci inside its structure. In conclusion, the CH-Ca-SV scaffold induces differentiation of DPCs into a highly mineralizing phenotype in the presence of dentin, creating a microenvironment capable of attracting pulp cells to its surface and inducing the overexpression of odontoblastic markers in a cell-homing strategy.

This study evaluated the effects of acid etching of the enamel and the combination of different light sources (halogen light, light-emitting diodes [LEDs], and LED/Laser) and the bleaching product on color change, penetration of hydrogen peroxide (H2O2), and cytotoxicity over time. The color change (ΔE) and the amount of H2O2 that permeated the tooth tissue were analyzed using a spectrophotometer. Cell metabolism and morphology were evaluated using the methylthiazol tetrazolium assay and scanning electron microscopy, respectively. The ΔE values and H2O2 permeation were not significantly different under any of the experimental conditions. Tooth whitening significantly reduced cell metabolism, regardless of whether a light source was used. Preconditioning the enamel did not influence the cellular metabolism in any group. In conclusion, combining the bleaching product with different light sources and/or preconditioning the enamel resulted in few significant changes in color, transenamel and transdentinal penetration of H2O2, or cytotoxicity and cell morphology.