Microleakage in Class V Composite Restorations after Chlorhexidine Gluconate Pre-treatments

Objectives: The use of chlorhexidine gluconate (CHX) has been proposed in the adhesive protocol to preserve the resin-dentin interface, because it inhibits the matrix metalloproteinases activity and also acts as a cavity disinfectant. However, it is important to study the effect of CHX on the marginal seal when is applied to enamel during the adhesive process. The aim of this study was to evaluate de microleakage of composite restorations with chlorhexidine as a primer in the adhesive protocol.
Methods: 50 human premolars were collected previous informed consent. Standardized class V cavities were conducted and the samples were randomly allocated into 5 groups to perform the resin fillings according to each treatment: Group 1 conventional etch-rinse adhesive protocol, Group 2: 0.12% CHX (Sigma-Aldrich, St. Lois, MO, USA) prior to performing the adhesive protocol, Group 3: enamel protection (Gingibarrier. SDI, Mel, Vic, Aus.) and 0.12% CHX prior to adhesive technique, Group 4: 2%CHX before to adhesive protocol, and Group 5: 2%CHX with enamel barrier prior to adhesive technique. All teeth were thermocycled for 3000 cycles (5 – 55°C) and immersed in 1%methylene blue for 24h at 37°C. The specimens were sectioned from facial to lingual and dye penetration was evaluated under stereomicroscopy at 20X. The dates were recorded in a 1 to 3 scale. Data analysis was performed with ANOVA (p<0.05).
Results: Highest microleakage was shown in group 5. There was no positive effect on the marginal seal of restorations in which contact with CHX was avoided. Effect of CHX on microleakage is concentration-dependent, 0.2%CHX (mean 1323,16 µm) had higher microfiltration than 0.12%CHX (mean 832,6 µm) (p=0.04).
Conclusions: Use of CHX gluconate in an adhesive protocol not influence the sealing ability of composite, although be applied on enamel. The 0.12%CHX may be used as pre-restorative procedure on dental tissue prior to application of adhesive system