Evaluation of the effectiveness of commercially antibacterial gels on micro-tensile bond strength applicable as cavity disinfectants

Abstract

Objectives: Insufficient removal of cariesaffected enamel and dentin represents a serious problem in restorative dentistry, as any bacteria remaining in the cavity after preparation may cause secondary caries. In order to provide an aseptic environment before pulp capping and lining, the use of an antibacterial material as a cavity disinfectant has been recommended. The aim of this study was to evaluate the role of commercially available gel formulations on the micro-tensile bond strength (MTBS) of a total etch system. Materials and Methods: Commercially available gel formulations with the contents of chlorhexidine (Corsodyl gel- %1CHX-COG), (Cervitec gel-%0.2 CHX+%0.2 sodium fluoride-CEG), aloe vera (Forever Bright-FOB) and hyaluronic acid (Gengigel-GEG) applicable as cavity disinfectants were used. No disinfectant was applied in the control group (CON). Ten human third molar free of caries were used in the study. Gels were applied for 1 minute just before bonding following total etch application in the gel groups, removed with sterile pellets and air-dried. Then composite restorations were applied. Ten composite-dentin rods (surface area of 1.0±0.1 mm2) were generated in each group from specimens stored in distilled water in 370C for 24 hours. These specimens then were subjected to MTBS test applying at a crosshead speed of 1 mm/min. Bond strength values between composite-dentin were recorded as megapascal and failure types were evaluated. Statistical differences were evaluated with one-way ANOVA and Tukey's test at the signifince level of p<0.05. Results: All the gels applied created lower MTBS levels compared with CON group (p<0.05).No difference was detected among the gels; CEG>COG>GEG>FOB (p>0.05). While mixed failure type was dominant in the CON group, only adhesive failure type was observed in all the other groups. Conclusions: Besides the antibacterial properties of these gel formulations, alterations occured in micromechanical adhesion and clinical performances should not be overlooked.