Is chlorhexidine-methacrylate as effective as chlorhexidine digluconate in preserving resin dentin interfaces?

ObjectivesThe aim of the current study was to evaluate the effect of 2% CHX and 2% CHX-methacrylate compared to the resin–dentin bonds created by a two-step etch-and-rinse adhesive system after 24 h, 6 min and 12 min.MethodsMicrotensile bond strengths and interfacial nanoleakage within resin–dentin interfaces created by Adper Single Bond 2, with or without CHX or CHX-methacrylate pre-treatment for 30 s on acid-etched dentin surfaces, were evaluated after 24 h, 6 min and 12 min of storage in distilled water at 37 °C.ResultsTwelve months of storage resulted in a significant decrease in microtensile bond strength in the control group, and significant increases in silver nanoleakage. In contrast, Single Bond 2 + CHX, and to a greater extent CHX-methacrylate, significantly reduced the rate of deterioration of resin–dentin interfaces over the 12 min water storage period, in terms of bond strength.ConclusionsSimilar to Single Bond 2 + CHX, Single Bond + CHX-methacrylates reduced the degradation of resin-bonded interfaces over a 12 month storage period. Thus it can be concluded that Single Bond 2 + CHX-methacrylate may be important to improve durability of bonded interfaces and therefore, prolong the life span of adhesive restorations.Clinical significanceAlthough CHX primers have been shown to enhance the durability of etch-and-rinse adhesives, that protection is lost after 2 h. The use of CHX-methacrylate should last much longer since it may copolymerize with adhesive monomers, unlike CHX.