Chlorhexidine Treatments: 0.12% and 2.0% on Early Dentin Bond Strength

Dentin bonds are being treated with Chlorhexidine(CHX) as a MMP inhibitor to stabilize the collagen hybrid layer against proteases. Objective: this study was design to determine if CHX affected the bond strength at 24 hours. Methods: OptiBond Solo Plus(OBS+,Kerr Inc) was used to bond Z250 composite(3m/ESPE) to dentin as a control group (n=10) using Espe/3M Scotchbond etchant. Two experimental Chlorhexidine(CHX) groups(n=10)were treated with 0.12%(Peridex)or 2%(Consepsis) applied for one minute after washing off the etchant and moist drying of the dentin before and after CHX treatment. The bond areas in recently extracted human molars were prepared by diamond saw at the height of contour perpendicular to the tooth's long axis. After etching(15sec.), the three groups were rinsed for 10sec. and forced air dried until moist and treated with or without CHX as required. Next,they were bonded with OBS+ using two coats with forced air drying 10 seconds followed by 20 seconds of VLC(500mw/cm2, Optilux-Demetron model 401) between and after the last coat. The Z250 cylinders 2mm high were formed in an Ultradent bonding jig and bonded with VLC for 40sec. The bonds matured in 37c water for 24 hours. An Instron machine applied a shear force parallel to the bond interface at 0.5mm/minute until fracture. Results: The average bond strength at 24 hours for the 0.12%, 2%CHX and control were 28.1+/-7.6MPa, 30.0+/-4.1MPa and 29.6+/-4.7MPa respectively. ANOVA indicated no statistical difference in 24hr strengths at p<0.05.Conclusion: The CHX treatments did not change the dentin 24hr bond strength.