Influência do HEMA em sistemas adesivos universais contendo 10-mdp, nas propriedades adesivas imediatas

Abstract

Purpose: to evaluated the effect of the presence of HEMA in universal adhesives systems with 10-MDP on the immediate adhesive properties to enamel and dentin. Material and methods: One hundred and twelve caries-free third molars were divided to be tested for dentin (n=72) and for enamel (n=48) tests. For each substrate, teeth were divided into 8 experimental groups according to the following: Adhesives: 1) Scotchbond Universal (SBU, 3M Oral Care, USA); 2) Gluma Bond Universal (GBU, Kulzer, Germany); 3) Solare Universal Bond (SUB, GC, America); 4) Zipbond Universal (ZIP, SDI, Australia) and Adhesive Strategy: Etch-and-rinse (ER) and Self-etch (SE) mode. For dentin tests, the occlusal third of the crown of all teeth was removed, and the adhesive protocol was applied. After completing restoration, specimens were sectioned into bonded sticks (0.8 mm2 ) and tested by microtensile bond strength (μTBS), in situ degree of conversion (DC) and nanoleakage (NL) by scanning electron microscopy. For enamel tests, teeth were sectioned in four parts (buccal, lingual, mesial and distal) and adhesive protocol was applied. After completing restoration, specimens were tested by microshear bond strength (μSBS). For in situ degree of conversion (DC) and nanoleakage (NL) evaluation to enamel, the specimens were sectioned in slices previously to be evaluated. Data of each substrate were subjected to two-way ANOVA and Tukey's test (α = 0.05) for each property evaluated. Results: The adhesives SBU and ZIP showed the highest μTBS, SBS, DC and lower values of NL when compared to GBU and SUB for both strategies (p=0.001). ER strategy presented higher values of μTBS and SBS when compared to SE strategy (p=0.001), with exception for SBU. Conclusion: The effect of the presence or not of HEMA in commercial universal adhesives systems containing 10-MDP on enamel and dentin adhesive properties appears to be material dependent.