| 3244 Polymeriazation Shrinkage and Temperature Increase of Provisional Materials | ||
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B. NAKFOOR1, P. YAMAN1, J.B. DENNISON2, and A.A. HERRERO1, 1University of Michigan, Ann Arbor, USA, 2University of Michigan, Plymouth, USA Objective: The purpose of this study was to evaluate the amount of shrinkage and heat generation during polymerization of bis-acrylic resin, polymethyl methacrylate resin, and polyethyl methacrylate resin provisional materials. Methods: Six provisional materials, three bis-acrylics (Luxatemp-Automix Plus, Integrity, and Protemp 3 Garant), one methyl methacrylate (Jet), and two ethyl methacrylate (Snap and Splintline) were used in this study. Ten specimens of each material measuring 1.5mm-2mm thick by 5mm in diameter were polymerized in a mold on a glass slide and linear shrinkage was recorded using the KmDATM measuring instrument. A first molar was prepared for a full crown and mounted in a typodont. A constantin-copper thermocouple was placed in the pulp chamber with one end stabilized on the surface of the preparation and the other connected to a chart recorder with accuracy to 1 degree F. Each material was used to fabricate ten provisionals on the tooth and the heat generated was recorded. A one-way ANOVA test and a Tukey multiple comparison test were conducted to determine if there is a significant difference among the provisional materials. Results: Integrity had the least volumetric shrinkage 6.22% (±1.72) and Jet had the highest 14.98% (±4.12). Jet had significantly more shrinkage than all other materials tested (p<0.05). Snap had significantly more shrinkage when compared to Integrity (p<0.05). Luxatemp-Automix Plus (42.0oF, ±0.47), Integrity (42.7oF, ±0.48), and Protemp 3 Garant (42.2oF, ±0.92) generated significantly (p<0.05) less heat than Snap (44.4oF, ±1.08), Splintline (46.6oF, ±0.97), and Jet (48.3oF, ±1.41). Conclusions: Jet had greater shrinkage and generated higher temperature during setting than the other provisional materials tested. The bis-acrylics (Luxatemp-Automix Plus, Integrity, and Protemp 3 Garant), had less shrinkage and generated lower temperatures then the methacrylates tested. Funded by University of Michigan, School of Dentistry, Student Research Project and NIDCR- DE007101 | ||
| Seq #344 - Prosthodontic Polymers 10:15 AM-11:30 AM, Saturday, 13 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
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Back to the Dental Materials: VI - Polymer Materials-Mechanical Properties and Degradation Program
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