| 1823 Effect of coping thickness on strength of aluminum oxide copings | ||
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S. BRIZGYS-MISKINIS, University of Michigan, Ann Arbor, USA, and M. SNYDER, University of Michigan, Ann Arbor, USA Objective: Procera AllCeram copings may need adjustment to as little as 0.40 mm. thickness. Little data exists regarding physical properties of copings thinner than 0.60mm., or for the selection of luting agents with which to cement them. This study investigated the strength of 0.40mm. compared to 0.60mm. copings, as well as the effect of different luting agents on load to fracture values. Methods: Sixty grade 2 titanium dies, pre-milled to standardized dimensions, were scanned using CAD/CAM technology. Aluminum oxide copings were fabricated to correspond to their specific dies. The outer surfaces of the copings were milled to 0.40 mm. or 0.60 mm. Group A contained fifteen 0.40mm copings cemented with Rely-X Vitremer, Group B- fifteen 0.40mm copings cemented with Fuji Plus, Group C- fifteen 0.60mm copings cemented with Rely X Vitremer, Group D- fifteen 0.60mm copings cemented with Fuji-Plus. Following cementation, samples were immediately placed under a 5 kg. static load for 10 minutes, then stored for 1 week in 100% humidity. Samples were placed into a jig ensuring uniform vertical force application and loaded to fracture at the rate of 0.50 mm./min. using a universal testing machine. Results: The mean load to fracture values were as follows: Group A= 455.00 N „b 103.61(S.D.), Group B= 802.65 N „b 261.98(S.D.), Group C= 872.65 N „b 299.69(S.D.) Group D= 1733.16 N „b 574.95(S.D.). Unpaired t- test was applied to data indicating both groups of 0.60 mm. copings exhibited higher load to fracture values than both groups of 0.40mm copings, and both groups cemented with Fuji-Plus exhibited higher load to fracture values than both groups cemented with Rely-X (P-valueƒ¬ 0.0001). Conclusions: Aluminum oxide copings of 0.60mm. achieved greater load to fracture values than 0.40mm. copings. Cementation with Fuji Plus cement achieved significantly greater load to fracture values than cementation with Rely-X.
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| Seq #205 - Ceramics: Stresses, Geometry, Fractography 10:15 AM-11:30 AM, Friday, 12 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
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Back to the Dental Materials: III - Ceramics and Cements Program
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