Long term clinical evaluation of three luting materials.

A last critical step in the completion of a cast restoration is permanent cementation. With the development of new luting agents the practitioner has to be aware of the physical and biological properties as well as the long term clinical performance of these materials. In this study three commonly used luting agents were evaluated over a four year period. The three cements, a zinc phosphate, a glass ionomer and a resin cement were tested for their reaction to periodontal tissues, pulpal response and other clinical parameters. In twenty six patients, 61 crowns, onlays or bridge abutments were cemented. Evaluations were made at 0 hour, after 7 days, 6 and 12 months and 4 years. In general the cements performed satisfactorily. Health of periodontal tissues adjacent to the crowns improved considerably after 7 days. Postcementation hypersensitivity appeared to be a negligible problem, which was attributed to the time span between preparation and cementation, which exceeded in most instances four weeks. The choice of a final luting agent should be based on anticipated postoperative pulpal reactions, rather than exclusive reliance on physical properties.