Abnormal dentin as a bonding substrate: Resin adhesion to carious and sclerotic dentin

Almost all adhesive bonding studies are done on normal dentin rather than on clinically relevant substrates such as caries-affected dentin or sclerotic cervical root dentin. Recently, a new bond-testing procedure has been developed which permits the measurement of small (ca. 1mm(2)) cross-sectional bonded area. It has been called the microtensile bond strength test (MTBS), and the bond strengths of current bonding systems to normal versus caries-affected dentin could be measured. Moreover, we could clarify the adhesive property of current resin systems to cervical sclerotic dentin. Recently, we reported the bond strengths of current bonding, systems to caries-infected dentin, and observed the interfacial morphology of resin-bonded caries-infected dentin by a transmission electron microscopy (TEM). These results suggested that even caries-infected dentin could be considered a. substrate for resin bonding, and that bonding agents can embed carious bacteria within the denatured dentin matrix. However, to establish the new caries treatment method named as modified sealed restoration (MSR), bonding to caries-infected dentin should be improved.