Bonding to caries-affected dentin using self-etching primers

Purpose: To evaluate resin bond strengths to caries-affected versus normal dentin using three self-etching primer adhesive systems. Materials and Meth ods: Carious lesions were excavated and then bonded with one of three self- etching primer adhesive systems (Clearfil Liner Bond 2, Clearfil Liner Bond 2V, A.R.T. Bond). A crown was then built up using a resin composite to a h eight of 4 mm. Five to six serial slabs approximately 0.7 mm thick were sec tioned perpendicular to the bonded surface. The bonded caries-affected or n ormal dentin areas were isolated to create an hourglass configuration with a cross-sectional area of approximately 1 mm(2). The specimens were subject ed to tensile stress at a crosshead speed of 1.2 mm/min. The bonded interfa ces to caries-affected and normal dentin were examined with an SEM. Results : Clearfil Liner Bond 2 and Clearfil Liner Bond 2V produced high bond stren gths to normal dentin, but significantly lower bonds than to caries-affecte d dentin. (P < 0.05). For A.R.T. Bond, there was no statistically significa nt difference between types of dentin. All three bonding systems produced t hin (+/- 0.5-1.5 mu m) hybrid layers in normal dentin. When used on caries- affected dentin, all self-etching primer systems produced hybrid layers tha t were twice as thick as those produced in normal dentin.