This study was designed to evaluate in vitro the efficacy of a novel at-home bleaching technique using 10% or 16% carbamide peroxide modified by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and its influence on the microhardness of bleached enamel. A total of 40 bovine incisors were divided into four groups (n=10) according to the bleaching agent used: 10% carbamide peroxide only; a blend of 10% carbamide peroxide and a CPP-ACP paste; 16% carbamide peroxide only; and a blend of 16% carbamide peroxide and a CPP-ACP paste. During the 14-day bleaching regimen, the samples were stored in artificial saliva. The Vickers microhardness and color of the teeth were assessed at baseline (T0) and immediately after the bleaching regimen (T14) using a microhardness tester and a spectrophotometer, respectively. The degree of color change was determined by the Commission Internationale de l'Eclariage (CIE) L*a*b* system (ΔE, ΔL*, Δa*, and Δb*) and Vita shade guide parameters. The data were analyzed by analysis of variance and the Tukey test (p<0.05). The teeth that were bleached with a blend of peroxide (10% or 16%) and the CPP-ACP paste presented increased microhardness values at T14 compared with T0, whereas the samples that were bleached with peroxide only did not show any differences in their microhardness values. All of the bleaching agents were effective at whitening the teeth and did not show a statistically significant difference using the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*) or the Vita shade guide parameters. The use of a CPP-ACP paste with carbamide peroxide bleaching agents increased the bleached enamel's microhardness and did not have an influence on whitening efficacy.

The purpose of this study was to evaluate the effect of mouthwashes on composite Knoop microhardness, and to assess the influence of the contact with mouthwashes and mechanical surface treatment on the shear bond strength of repaired composite resins. Methods: One hundred twenty composite resin (GrandioSO) specimens were prepared and randomly divided into four experimental groups, according to the used mouthwash (distilled water; Listerine Teeth & Gum; Eludril Perio; Lacer Oros). After a period of 5 days in water (37ºC), during which the specimens were submitted to twelve cycles of 2 hours of immersion in the respective mouthwash, the Knoop microhardness was determined. Then, each group was divided into three subgroups based on the mechanical surface treatment performed (no treatment; 50-µm Al2O3 sandblasting; abrasion with diamond bur), the repair protocol was performed (Solobond M and GansdioSO) and specimens were submitted to shear bond strength tests until failure. Data were analyzed using ANOVA followed by Student-Newman-Keuls post-hoc tests (α=0.05). Results: The group of specimens aged in distilled water presented a significantly harder surface than the other experimental groups (p<0.05). No statistically significant differences were found (p>0.05) between other groups. Neither the immersion media (p=0.214) nor the mechanical surface treatments (p=0.165) had a significant effect on the bond strength. Conclusions: Although the hardness of the composite was negatively affected by contact with the mouthwashes used in this study, the bond strength of composite repair was not affected.

Wound infection hinders adequate healing, being particularly grievous and prevalent in burn wounds and chronic wounds. Wound infection extends inflammation, preventing epithelialization and angiogenesis. Therefore, infection prolongs healing time, steeply increases treatment costs and degrades patients wellbeing. One successful strategy to control wound infection is to apply an active wound dressing, able to eliminate or significantly reduce the microbial population present at the infection site. Silver nanoparticles (AgNPs) are a multipurpose antimicrobial agent with a wide scope of applications which include wound dressings. Nevertheless, several studies denote AgNPs dose-dependent cytotoxicity, and their capability to bypass the blood-brain barrier and induce a neurotoxic effect. Hence, we propose to adopt two different strategies to attempt the simultaneously immobilize and increase the load of AgNPs within the wound dressing fabric. Thus, the envisaged objective is to prevent potential systemic cytotoxicity /through immobilization and to improve its antimicrobial capability due to the higher concentration of AgNPs. Two different approaches were used: i. AgNPs were suspended in an alginate (ALG) solution, ii. AgNPs were embedded in Mordenite (MOR) zeolite, followed by addition of an ALG solution. Both suspensions were incorporated into polyester fabric assisted by its surface activation by dielectric barrier discharge (DBD) plasma treatment. The bactericidal and virucidal effectiveness of each composite was tested against bacteria species known to induce nosocomial infections and a bacteriophage that is a potential surrogate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Two distinct antimicrobial analysis were used to provide insights on the antimicrobial effectiveness of the obtained composites and to indirectly assess the release of AgNPs.

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