Int J Oral Maxillofac Implants 17 (2002), No. 4 15. Aug. 2002
Purpose: Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations. While the functional life spans of these cements are unpredictable, the relative retentiveness of various permanent and provisional cements between dental alloys and titanium abutments is not well documented. The aim of this study was to compare the uniaxial resistance forces of permanent and provisional luting cements used for implant-supported crowns. Materials and Methods: Seven samples on 4 different abutments (a total of 28 crowns) were cast using a gold-platinumpalladium alloy. The crowns were cemented with 3 different provisional, polycarboxylate, and glassionomer cements and 1 zinc phosphate cement. After storage of samples in artificial saliva for 24 hours, tensile tests were performed. Results: While the highest uniaxial resistance forces were recorded for polycarboxylate cements, provisional cements exhibited significantly lower failure strengths (P < .05). The uniaxial resistance force of cements on different abutments exhibited notably different trends; however, more force was required to remove crowns cemented to long abutments (P < .05). Discussion: Glass-ionomer and zinc phosphate cements may be used to increase the maintenance of implant-supported crowns. Temporary cementation of such restorations may necessitate frequent recementation, particularly for restorations on short abutments. Conclusions: Temporary cementation may be more suitable for restorations supported by multiple implants.