| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
Nine kinds of resin composites for crown and bridge were examined to evaluate those properties. Observations of filler shape, filler contents were performed to evaluate filler type, since those in resin composites affected properties significantly. Curing properties of resin composites for crown and bridge were also measured for the depth of cure with light exposuring units and the structure of matrix resin. Moreover, mechanical properties were evaluated by fracture toughness test, direct tensile, bending, and hardness tests.
Filler, curing, and mechanical properties differed in each resin composites for crown and bridge significantly. These resin composites had lower filler contents, and smaller particle fillers than resin composites for restoration. We could classify two types of resin composites for crown and bridge. The one was for veneering to anterior, and the other was for applying to posterior restorations. Those filler type and composition differed in types for applying significantly. Mechanical properties of resin composites for crown and bridge were lower than those of resin composites for restoration.
Wear of resin composites for crown and bridge was determined by using an OHSU type wear tester simulating wear patterns in an oral condition. We found some resin composites for crown and bridge had high wear rate for antagonistic enamel. Wear characteristics was not only affected by mechanical properties but also by filler properties. These results suggested that we had to consider for many factors such as testing conditions of a wear machine, antagonistic materials, and environments, since resin composites for crown and bridge suffered more severe conditions in oral environment for longer time.
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