This randomized clinical trial was initiated to study the effect of two restorative procedures on the clinical quality and longevity of class-III resin restorations. The material consisted of 52 pairs of class-III restorations in the microfilled resin Silar completed with two modifications of the conventional acid-etch restorative procedure: A) beveling of the margins of the cavity preparations, and B) treatment of the etched butt-joint cavities before filling with the dentin-adhesive NPG-GMA/ethanol together with re-etching and surface coating of the finished restorations with low viscous resin. The restorations were examined at base line and after 2, 4, 6, and 11 years. The cumulative 11-year survival rate for both types of restorations was 84%. Marginal discolorations, marginal discrepancies, and secondary caries were most often recorded corresponding to the beveled type-A restorations, whereas the esthetic quality of the two types of restorations was almost identical. Surface discolorations were most often recorded among smokers, and significant correlations were found between the patients' consumption of alcoholic beverages and corpus discoloration, surface discoloration, and surface wear of restorations.