Influence of additional adhesive application on the microtensile bond strength of adhesive systems.
This study evaluated microtensile bond strength (pTBS) when an additional adhesive layer was applied to the dentin surface. Thirty-five human third molars were flattened to expose the occlusal dentin surface. The teeth were randomly assigned to 7 experimental groups: G1-Single Bond (SB); G2-additional layer of SB; G3--a layer of Scotchbond Multi-purpose (SMP) adhesive applied over SB; G4-Clearfil SE Bond (CE); G5-additional layer of CE; G6-Adper Prompt (AP) and G7-additional layer of AP. For the G2, G3, G5 and G7 groups, the first adhesive layer was light-cured before application of the additional layer. After bonding procedures, 5-mm high composite crowns were incrementally built up. The samples were sectioned to obtain 0.9 x 0.9 beams, which were tested under tension at a crosshead speed of 0.5-mm/minute until failure. The failure mode and adhesive thickness were evaluated under SEM. The pTBS data were analyzed by 1-way ANOVA and post-hoc Ducan's Test (a=0.05). Mean adhesive thickness was analyzed by 1-way ANOVA and post-hoc Tukey's test (a=0.05). The results indicated that G3 presented the highest microTBS and the thickest adhesive layer. G6 and G7 presented the lowest microTBS values. When solvent-free adhesives systems were used, microTBS values were not affected by the thicker layer.
de Silva
André Luís Faria
AL
Department of Restorative Dentistry, Piracicaba School of Dentistry, University of Campinas, Piracicaba, São Paulo, Brazil. andrelfs@fop.unicamp.br
Lima
Débora Alves Nunes Leite
DA
de Souza
Grace Mendonça Dias
GM
dos Santos
Carlos Tadeu Dias
CT
Paulillo
Luís Alexandre Maffei Sartini
LA
D000268:Adhesiveness; D000269:Adhesives / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010755:Organophosphates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D000269:Adhesives; C489661:Adper Prompt Self-Etch; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D010755:Organophosphates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C467914:TPH spectrum; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate