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.

Objective: This study aimed to evaluate the progression of sealed non‐cavitated dentinal occlusal caries in a randomised controlled clinical trial. Materials and methods: Sixty teeth with non‐cavitated dentinal occlusal caries were selected in patients with a high risk for caries. Patients were randomly divided into two groups so that each group included 30 teeth. Patients in the experiment group were given oral hygiene instructions and a fissure sealant. Patients in the control group were given oral hygiene instructions only. Caries progression and sealant loss were monitored over a period of 36 months by clinical and radiographic examinations. Results: Clinical and radiographic progression of caries was significantly more frequent in the control group than in the experiment group. Three teeth lost their sealant and showed caries progression, but this was apparent only at the 12‐month follow‐up. At the 24‐ and 36‐month recall appointments, neither sealant loss nor caries progression were observed. Conclusion: The pit and fissure sealant utilised in this study was shown to be effective in arresting carious lesions at 36 months.

The use of a CPP-ACP paste mixed to carbamide/hydrogen peroxides can decrease adverse side-effects from tooth bleaching on an enamel surface.

The use of CPP-ACP was able to prevent negative changes in roughness and hardness of bovine enamel when associated to hydrogen peroxide, and might be applied before/after the bleaching protocol.

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