Módulo de elasticidade e grau de conversão de monômeros de sistemas adesivos autocondicionantes e primer e adesivo combinados

Abstract

Objectives: The aims of this study were to evaluate the elastic modulus and the monomer conversion of self- etching adhesives (Single Bond Universal and Clearfil SE Bond) and two- steps etch-and-rinse adhesives (primer + adhesive in the same bottle, Adper Single Bond 2 and Gluma 2Bond). The null hypothesis was that two-step adhesive systems will have higher degree of monomer conversion and a higher elastic modulus than the self-etching ones. Materials and methods: On dentin disks obtained from 10 extracted third molars were applied self- etching and etch-and-rinse adhesive systems according to manufacturer's instructions and light cured by a LED light. Right after, the specimens were submitted to elastic modulus by atomic force with 50g load for 10s. The degree of conversion of the adhesives was calculated by Fourier Transform Infrared Spectroscopy (FTIR). Results: The Single Bond 2 adhesive system presented the highest monomer conversion result (88%) followed by Universal Single Bond (79%), Gluma 2Bond (71%) and Clearfil SE Bond (69%). The results for elastic modulus (MPa) were (means followed by the same letter did not present statistical difference for Tukey (p≥0,05)): Single Bond 2, 2319 (A); Single Bond Universal, 2051 (AB); Gluma, 2038 (AB); Clearfil SE Bond, 1788 (B). Conclusion: lt is not possible to infer that, as a rule, conventional adhesives systems with combined primer and adhesives will have a better performance in terms of the degree of monomer conversion as well as modulus of elasticity when compared to self-etching agents.