A 3-year follow-up clinical trial of two experimental Bayer total-etch adhesive systems and two commerical total-etch systems. Clearfil Liner Bond System and Scotchbond Multi-Purpose, was conducted to evaluate their clin ical effectiveness in Class V cervical lesions. Four hundred twenty abrasion-erosion lesions were restored randomly using the four adhesive systems. There were two experimental cavity designs, in which the adjacent enamel margins either were or were not beveled and acid etched. Clearfil Liner Bond System and Scotchbond Multi-Purpose demonstrated high retention rates in both types of cavity design at 3 years. The two experimental Bayer systems scored much lower retention rates in both cavity designs at 3 years. None of the systems guaranteed margins free of microleakage for a long time. At 3 years, superficial, localized marginal discolorations were observed, the least for Clearfil Liner Bond System, followed by Scotchbond Multi-Purpose and the two experimental systems. Small marginal defects were recorded at the cervical dentin and the incisal enamel margin. Retention of Clearfil Liner Bond an d Scotchbond Multi-Purpose appears to be clearly improved over earlier systems, but marginal sealing remains problematic. The two Bayer systems were found to be clinically unreliable.