The purpose of the present study was to evaluate the influence of different disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent. Forty non carious human molars were selected. Teeth were embedded in acrylic resin and ground until the exposure of a flat superficial dentin surface. Teeth were randomly divided in 4 groups and treated as follows: Group 1 - 2.5% NaOCl for 40 seconds; Group 2 - 2% chlorhexidine for 40 seconds; Group 3 - 1.23% acidulated fluoride for 4 minutes; and Group 4 - control (without disinfectant solution). Following treatments, Scotchbond Multipurpose Plus® (3M) was used according to the manufacturer’s instructions. After that, the test specimens were built with composite resin (Z100®-3M), using a standard Teflon matrix. The specimens were stored in distilled water for 24 hours at a temperature of 37ºC. The tensile strength test was performed using a Mini Instrom testing machine. The mean values obtained for each group, in MPa, were: Group 1 - 7.37 (± 2.51); Group 2 - 11.25 (± 4.65); Group 3 - 9.80 (± 3.11); and Group 4 - 10.96 (± 3.37). The results were submitted to statistical analysis using the ANOVA test, and no statistical significant differences among the groups were found. It can be concluded that the different disinfectant substances used in this research do not adversely affect dentin adhesion.

The use of a liquid acid etchant created higher bond strength values in the apical region.

This study evaluated by scanning electron microscopy (SEM) the morphological changes in occlusal fissure enamel, of permanent models, irradiated by Er:YAG laser using contact and noncontact fiberoptics in vitro. Previous studies have demonstrated the efficacy of Er:YAG laser for dental hard tissue removal and cavity preparation. The treatment of occlusal fissures in noncarious permanent human molars (n = 9) was carried out with Er:YAG laser (KEY Laser II) using handpiece no. 2051, noncontact, focused (12 mm), water spray-cooled, pulse energy 200 mJ, and frequency 2 Hz (group 1), and handpiece no. 2055 with a quartz fiberoptic 50/10, in contact, air cooled, pulse energy setting of 350 mJ and frequency 2 Hz (group 2) and 400 mJ/2 Hz (group 3). The specimens were sectioned, dehydrated in a graded series of aqueous ethanol, dried, and sputtering with gold. Morphological change analysis on occlusal fissures was performed by SEM. Group 1 showed removal of fissure debris and predominantly enamel etching-like patterns, and groups 2 and 3 showed irregular edges, melting, and recrystallization of fissure enamel, with a lava-like structure and bubble-like voids. The results of this in vitro study suggest that the irradiation of fissures by Er:YAG laser using a fiberoptics (contact and air cooled) produced melting and recrystallization of fissures enamel. Further studies are required with different energy parameters and water cooling to evaluate the thermal effects on teeth.

Comparação clínica entre diferentes métodos de diagnóstico de cárie proximal. O objetivo do presente estudo foi avaliar a capacidade cinco métodos de diagnósticos de cárie proximal, que são: radiografia interproximal convencional (RC), radiografia interproximal digitalizada (RD), exame clínico (EC), inspeção visual da superfície (IV) e moldagem da superfície proximal (M) após 24 horas da colocação dos elásticos para a separação do dente e tendo como o critério de validação para todos os métodos testados a abertura da cavidade (AC). Quarenta pacientes, com idades entre 14 e trinta anos foram examinados. Os exames foram realizados por três examinadores. Duas radiografias interproximais foram feitas de cada paciente. Antes dos exames clínico e visual realizou-se a limpeza das superfícies com pedra pomes e água. A inspeção visual e a moldagem foram realizadas 24 horas após a separação temporária dos dentes. A RD foi obtida através da RC. O acordo entre dois examinadores calibrados no EC ou IV ou RC em relação a presença de cavidade foi determinante para a AC. Os valores kappa, a sensibilidade e a especificidade observadas foram respectivamente: RC: 0,78; 0,78; 0,96; RD: 0,52; 0,60; 0,92; EC: 0,43; 0,32; 1,00; IV: 0,60; 0,49; 1,00; M: 0,57; 0,39; 1,00. Permitindo as seguintes conclusões: a RC e a RD mostraram melhores resultados para os diferentes parâmetros avalizados; EC e M mostraram alta especificidade e baixa sensibilidade; a IV mostrou moderada sensibilidade e alta especificidade; se faz necessário a associação de métodos para melhor diagnóstico de lesões de cárie proximal.