Estudo in vitro do efeito antibacteriano e resistência à tração diametral de cimentos resinosos incorporados com diacetato de clorexidina

Abstract

The aim of this study was to test the antibacterial capacities and diametral tensile strengths of two commercially available resin cements to which chlorhexidine diacetate was added. The cements were then compared to the same unmodified cements. Thirteen cylindrical samples were prepared from either two resin cements or the same cements modified by the addition of chlorhexidine diacetate at 1% w/w, with a total of 52 samples. The cements tested included Rely X U200 and RelyX Ultimate. There were four experimental groups, with Group 1 using RelyX U200 cement, Group 2 using RelyX U200 cement plus 1% DCHX, Group 3 using RelyX Ultimate cement and Group 4 using RelyX Ultimate plus 1% DCHX. Three samples from each group were assessed for antibacterial properties against Streptococcus mutans with an agar diffusion test. Ten samples of each cement, with and without chlorhexidine diacetate, were also tested 1 day after the initial setting for their diametral tensile strength applied with an EMIC machine. The results were analyzed using either oneway anova and T student test. The addition of chlorhexidine diacetate resulted in resin cements with antibacterial properties that persisted through for up to 48 hours. The addition of chlorhexidine did not reduce the diametrical strength of the cements p=0.583. Even within the limitations of this study, it is possible to conclude that the addition of chlorhexidine diacetate to resin cements rendered all cements antibacterial against S. mutans. It was also possible to conclude that the DCHX incorporated into resin cements at a concentration of 1% did not compromised their 24 h diametral tensile strength, regardless of the cement tested.