ABSTRACT
OBJECTIVES: The aim of the present study was to evaluate the effect of whitening mouth rinses alone and in combination with conventional whitening treatments on color, microhardness, and surface roughness changes in enamel specimens. MATERIALS AND METHODS: A total of 108 enamel specimens were collected from human third molars and divided into 9 groups (n = 12): 38% hydrogen peroxide (HP), 10% carbamide peroxide (CP), 38% HP + Listerine Whitening (LW), 10% CP + LW, 38% HP + Colgate Plax Whitening (CPW), 10% CP + CPW, LW, CPW, and the control group (CG). The initial color of the specimens was measured, followed by microhardness and roughness tests. Next, the samples were bleached, and their color, microhardness, and roughness were assessed. Data were analyzed through 2-way analysis of variance (ANOVA; microhardness and roughness) and 1-way ANOVA (color change), followed by the Tukey post hoc test. The Dunnett test was used to compare the roughness and microhardness data of the CG to those of the treated groups. RESULTS: Statistically significant color change was observed in all groups compared to the CG. All groups, except the LW group, showed statistically significant decreases in microhardness. Roughness showed a statistically significant increase after the treatments, except for the 38% HP group. CONCLUSIONS: Whitening mouth rinses led to a whitening effect when they were used after conventional treatments; however, this process caused major changes on the surface of the enamel specimens.
Subject(s)
Humans , Dental Enamel , Hydrogen Peroxide , Molar, Third , Mouth , Tooth Bleaching Agents , Tooth Bleaching , Tooth , UreaABSTRACT
The study aims to evaluate the bond strength of sealants on deciduous molars. Clinpro ™ XT, Vitremer ™, Fluroshield and Optibond FL materials were applied to the occlusal surface of 40 deciduous lower molars (n = 5). The teeth were prepared for the micro tensile test, obtaining a specimen in a stick format with a cross-sectional area of 0.8 mm2 . After 24 hours and 6 months of restorative procedures, the specimens were traversed in universal test machine. The statistical analysis used the tooth as experimental unit, considering the adhesive and mixed fractures data, through Variance Analysis of repeated measures and Tukey tests (α = 0.05). There was a difference among the adhesion of the materials in 24 h, with higher union strength for Optibond FL (31.20 ± 1.36 MPa), significantly higher than that of Clinpro ™ XT (20.23 ± 1.16 MPa), Fluroshield (24.61 ± 2.76 MPa) and Vitremer™ (21.31 ± 2.32 MPa), which were similar. After 6 months of storage, the Clinpro ™ XT bond strength remained (22.18 ± 2.91 MPa), Optibond FL decreased (20.77 ± 1.53 MPa), but remained similar to that of Clinpro ™ XT in 6 months. The lowest adhesion values at 6 months were of Fluroshield (11.14 ± 1.98 Mpa) and Vitremer (5.29 ± 0.58 Mpa). It was concluded that the bond strength of the sealants to the occlusal surface of the deciduous molars was influenced by the material, with Clinpro ™ XT being the only material that maintained the bond strength values after 6 months. (AU).
O presente estudo teve como objetivo avaliar a adesão de selantes em molares decíduos. Os materiais Clinpro™ XT, VitremerTM, Fluroshield e Optibond FL foram aplicados na superfície oclusal de 40 molares inferiores decíduos (n=5). Os dentes foram preparados para o ensaio de microtração, com obtenção de corpo-de-prova em formato de palito com área de seção transversal de 0,8 mm2 . Após 24 horas e 6 meses da realização dos procedimentos restauradores, os espécimes foram tracionados em máquina de ensaio universal. A análise estatística usou como unidade experimental o dente, considerando os dados de fraturas adesivas e mistas, pelos testes de Análise de Variância de medidas repetidas e Tukey (α=0,05). Houve diferença entre a adesão dos materiais em 24 h, com maior resistência de união para o Optibond FL (31,20 ±1,36 MPa), significativamente maior que a do Clinpro™ XT (20,23 ±1,16 MPa); Fluroshield (24,61 ±2,76 MPa) e VitremerTM (21,31 ±2,32 MPa) foram semelhantes. Decorridos 6 meses de armazenamento, a resistência de união do Clinpro™ XT se manteve (22,18 ±2,91 MPa) e a do Optibond FL diminuiu (20,77 ±1,53 MPa) mas se manteve semelhante à do Clinpro™ XT em 6 meses. Os menores valores de adesão em 6 meses foram do Fluroshield (11,14 ±1,98 Mpa) e do Vitremer (5,29 ±0,58 Mpa). Concluiu-se que a resistência de união dos selantes à superfície oclusal dos molares decíduos foi influenciada pelo material, sendo o Clinpro™ XT o único material que manteve os valores de resistência de união após 6 meses. (AU).