The influence of natural products incorporation on mechanical and antimicrobial properties of adhesive systems

Abstract

The evolution of adhesive systems has provided significant improvement in the quality of marginal sealing and durability of the restorations. Besides adhesive monomers, some of them have solvents, initiators and other components such as fluoride, filler particles and antibacterial agents, which appear to modify the clinical behavior of these adhesives. This project aims to evaluate the strength and morphology of the dentin-adhesive-composite resin interfaces, the flexural strength and modulus of commercial and experimental adhesives containing natural antimicrobial agents, and antimicrobial activity of these bonding agents. Coronal dentin will be used in bond strength test and morphology of dentin-composite resin interface observations. The microtensile test will be performed after 24 hours of specimen preparation and after 1 year of storage in artificial saliva. The dentin-adhesive-resin interface will be evaluated by confocal laser microscopy. For flexural strength and modulus tests of the adhesive will be prepared silicone matrices with dimensions of 0.6 mm in thickness and 6.2 mm in diameter. In antimicrobial activity analysis, adhesive systems will be tested against the biofilm formation of Streptococcus mutans on hydroxyapatite surface. The research project developed during Master Program (Fapesp 2010/13599-0) included the evaluation of six dental adhesives. Three of them containing antimicrobial components: glutaraldehyde, chlorhexidine and MDP-bromide monomer. Microbiological analyzes were used to measure the zone of inhibition and determination of bactericidal activity by contact. This Ph.D project continues the research work done during the Master Program, but using experimental materials and natural antimicrobial substances under patent protection. The expected results of this study are to obtain adhesive systems containing naturally occurring agents with mechanical and effective antimicrobial properties. In addition, the scholarship and financial support requested will be important for the graduate student, which has worked full time, to continue research and scientific activities started in the Master Program successfully, now in the Ph.D course.