Influence of repeated opening of bottle on the bond strength of ethanol-based one-step adhesives

Abstract

The present study evaluated the influence of repetitive opening of two one-bottle bonding systems on tensile bond strength to dentin. The products tested were Excite (Ivoclar/Vivadent) (ethanol) and Single Bond (3M/ESPE) (ethanol and water). Ninety extracted hu- man third molars were used. The roots were removed and the cro- wns were invested in acrylic resin. A group of 15 teeth was separated for each bonding system and each test periods: initial, 60 and 120 days. For the tensile bond strength test, specimens of composite resins Tetric®Ceram (Ivoclar/Vivadent) and Z100 (3M/ESPE) were built on the dentin surface of the same brand of the tested adhesives. The specimens were stored in 37 ºC sa- line solution for 24 hours and sub- mitted to tensile bond tests on a universal testing machine (EMIC DL-2000) with a crosshead speed of 0.5 mm/min. The results (MPa) were analyzed by the analysis of variance ANOVA and Tukey test (p=0.01). The means obtained in the initial period, 60 and 120 days were respectively: 21.01 MPa; 23.13 MPa; 18.02 MPa, for Excite and 18.32 MPa; 22.99 MPa; 22.33 MPa for Single Bond. The initial means for Excite did not indica- te significant difference from the ones obtained during 60 and 120 days. The initial means for Single Bond indicated a significant diffe- rence for the period of 60 days, but did not indicate a significant di- fference for 120 days. The tensile bond strength to dentin after the repetitive opening of the bottle of adhesive during 120 days did not indicate a statistically significant difference for both adhesives in relation to the initial period. Key words: adhesives, dentin, composite resins, solvent, tensile strength.