The etched cast restoration--clinical techniques and long-term results

The etched cast restoration was introduced as the "Maryland bridge" in 1980. The technique has continued to evolve with modifications in tooth structure and framework design as well as improvements in luting resins, including some that chemically bond to the alloy. The conservation of tooth structure and the avoidance of involving the gingival crevice remain the major advantages of the technique. Research has shown that the etched cast restoration, when designed with a retentive framework, exhibits bond strengths comparable with those of traditional complete coverage restorations. The main purpose for this retentive framework is to limit the stresses placed on the resin, thus preventing the phenomenon of stress fatigue in the resin. Clinical observations and an 11-year clinical study involving 127 restorations confirm this research. The long-term success rate in this study was 92.9%.