With the proven results of etched resin techniques, there has been renewed interest in conservative cavity design with a view to the preservation of healthy tooth material. Among the newer techniques showing long-term success are preventive resin restorations. This treatment has several distinct advantages over traditional amalgam restorations, but it requires excellent isolation from salivary and moisture contamination. Three types of preventive resin restorations, with high rates of retention over a seven-year period, have been described. Minimal exploratory openings in enamel are filled with pit and fissure sealants, whereas isolated carious lesions are removed without any extension into the surrounding healthy tooth. The cavity is obturated with filled resin and the unaffected pits and fissures are protected with pit and fissure sealant. The success rate of these conservative restorations can be enhanced by paying strict attention to technique, thereby ensuring a noncontaminated surface. A number of suggestions are offered on how this success rate can be increased.