Retention and Marginal Adaptation of Luting Agents on Dental Implant-Supported Prostheses

Purpose: Selecting the appropriate luting agent is critical to the long-tem efficacy of cement-retained implant prostheses, in part because some luting agents may prevent retrieval of prostheses for future maintenance. At the same time, a strong marginal seal will prevent marginal leakage that can result in toxin formation and inflammation around implant fixtures. The present study evaluated the seal strength and marginal leakage of 7 different luting agents used with implant abutment/analog assemblies. Materials and methods: Of the agents tested, two were definitive and five were provi-sional cements. The definitive cements were Maxcem resin cement and zinc phosphate cement. The provisional cements included three zinc-oxide eugenol and noneugenol cements (namely, Opotow, Temp Bond and Temp Bond Noneugenol), one acrylic/urethane-based cement (ImProv), and one resin-based cement (premier). Thirty-five Steri-Oss implant abutment/analog assemblies and cast superstructures were used to test these seven cements (five per cement). Following cementation of the superstructures onto the implant abutments, each specimen was subjected to 1,000 cycles on a thermocycling machine (0˚C-55˚C) and 100,000 cycles on a chewing machine (75N). The cement failure stress and marginal leakage were tested for each specimen. The data were analyzed with one-way ANOV A, Duncan's Multiple Range Analysis and Kruskal-Wallis test. Results: The cement failure stress mean of the Maxcem resin cement was significantly higher than that of the other cements (P＜.0001), and the mean marginal leakage scores for ImProv, Optow, and Premier were significantly lower than those of the other cements (p =.005). Conclusions: The definitive cements exhibited much stronger retention than the provisional cements. However, there were no significant differences in retentive properties among the five provisional cements themselves. As for marginal leakage, ImProv and Premier showed the least marginal leakage, while Temp Bond and Temp Bond Noneugenol had the highest leakage among the luting agents tested.