Background/Aim. Theoretically, agitation of self-etch adhesive and solutions can be significantly accelerated by the use of the rotary brush. The aim of this study was to evaluate application of a universal adhesive in a self-etch mode and a self-etch adhesive using a rotary brush active application technique by microshear bond strength (?SBS) test. Methods. The crown parts of 20 bovine teeth were separated from their roots, embedded in acrylic blocks and enamel surfaces were prepared. The prepared crowns were divided into four groups according to the adhesive system tested (Nova Compo-B Plus, and Optibond All-in-one), and application technique (manual active application and rotary brush active application). Bonded samples were immersed in distilled water for 24 h before bond strength testing by ?SBS test at 1.0 mm/min. Data were analyzed using non-parametric tests (p = 0.05). Results. Both adhesives, applied by rotary brush active application technique, showed significantly higher enamel bonding strength compared to the manual active application technique. Conclusion. Application of self-etch adhesives to enamel with a rotary brush active application technique can significantly increase initial resin-enamel bond strength compared to the manual active application.

Background and aims: Adhesion durability of resin adhesives with Er,Cr:YSGG laser irradiated-enamel has been rarely investigated in the literature. Thus, the present study evaluated the influence of long-term water storage (12-month) on resin bond strength with the enamel irradiated with Er,Cr:YSGG laser irradiation deployed different settings. Materials and methods: The flattened enamel samples of 35 bovine teeth, which were embedded into acrylic blocks, were randomly divided into 7 groups (n = 5), according to surface treatments using Er,Cr:YSGG laser with different parameters 6 W/20 Hz, 6 W/35 Hz, 6 W/50 Hz, 3 W/20 Hz, 3 W/35 Hz, 3 W/50 Hz or no laser treatment (Bur-treating as a control). Adper Single Bond 2 was applied to the prepared enamel and the composites were placed and cured. Resin-enamel sticks with an approximate cross-sectional area of 0.8 mm² were obtained, and microtensile bond strength (μTBS) tests were performed at 24-hour and 12-month of water storage after bonding. The μTBS data were analyzed with twoway ANOVA and Tukey tests (p < 0.05). Results : 24-hour water storage after bonding, the μTBS to laser-irradiated enamel in the 6W/ 20 Hz group was significantly lower than those of bur-treated. However, 3 W/50 Hz showed significantly higher μTBS than those of bur-treated. Two-way ANOVA revealed that 12-month water storage did not influenced μTBS. Conclusions: It may be concluded that, initial bond strength to Er,Cr:YSGG laser irradiated-enamel might be significantly influenced by power and pulse frequency settings. However, resin bonding to laser-irradiated enamel was stable over 12-month water storage regardless of tested laser parameters.