In vitro study of the adhesion to dentin promoted by an universal system:futurabond M+ - with and without pulpar pressure

Tese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2016Objectives: To evaluate the microtensile bond strength (μTBS) and the resin-dentin interface morphology of an universal adhesive system, Futurabond M+ (FB), in the etch-and-rinse strategy and in the self-etch strategy, with and without pulpal pressure. Methods: Forty caries-free extracted human molars were randomly assigned to four experimental conditions: Group A - FB with etch-and-rinse strategy; Group B - FB with self-etch strategy, both without pulpal pressure; Group C - FB with etch-and-rinse strategy; Group D - FB with self-etch strategy, both with pulpal pressure. The specimens were then stored in distilled water in an incubator for 24 hours at 37ºC. Subsequently, teeth were longitudinally sectioned with a low-speed diamond saw under water irrigation, dividing them into two halves. One of the halves was then longitudinally sectioned in both “x” and “y” directions across the bonded interface, creating sticks with a cross-sectional area of approximately 1mm2. The other half was sectioned in order to create 2 quarters of the initial specimen and used for SEM observation. Statistical analysis was performed through the SPSS program. Kruskal-Wallis and Mann-Whitney tests were performed when the assumption of normality and homogeneity were not observed. Results: There were statistically significant differences in μTBS (p