2007 Fiscal Year Final Research Report Summary
Improvement in wear resistance of fiber-reinforced composites under the appropriate polymerization conditions
| Project/Area Number |
18390525
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | Nihon University |
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Principal Investigator |
MASTUMURA Hideo Nihon University, School of Dentistry, Professor (40199857)
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| Co-Investigator(Kenkyū-buntansha) |
HIROYASU Koizumi Nihon University, School of Dentistry, Assistant professor (20339229)
MIKA Furuchi Nihon University, School of Dentistry, Assistant professor (90386079)
TANOUE Naomi Nagasaki University, Hospital of Medicine and Dentistry, Assistant professor (70231660)
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| Project Period (FY) |
2006 – 2007
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| Keywords | composite / wear / bonding / fiber |
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| Research Abstract |
The purpose of the current study was to evaluate the effect of a metal priming agent on wear resistance of gold alloy-composite joint. Four types of plate specimens mimicking occlusal surface of restorations were prepared ; composite (Estenia C&B) alone, type 4 gold alloy alone, composite-alloy joint without priming agent, and composite-alloy joint bonded with a priming agent (Alloy Primer). Three-body wear test was performed using the plate specimens, gold alloy antagonist, and poly(methyl methacrylate) slurry. Joined specimens with priming exhibited less wear depth and less height loss of the antagonist than the joined specimens without priming. Both composite and gold alloy single plates showed smaller wear values than the jointed specimens. Also, wear of the Estenia C&B composite material was less than that of the type 4 gold alloy. The use of metal priming agent at the composite-alloy interface is recommended in fabrication of composite veneered restorations.
The next study examined effects of monomer composition, original filler content, and application of centrifugal force on resulting filler loading of composites. Either Bis-MPEPP or UDMA was mixed with TEGDMA at a molar ratio of 1 : 1. Silane treated silica (14-20 wt%) was added to each mixture. After the mixtures were centrifuged and then light-polymerized, the filler inorements of 2.0 mm high disk-shaped sections of specimen were determined as the rate of increase compared to uncentrifuged filler contents. Both the original filler loading and the monomer composition influenced the filler content of the centrifuged composites. Fillers in Bis-MPEPP-based composites exhibited a higher rate of condensation after application of centrifugal force than did UDMA-based composites. The results are suggestive of the relationships among the composition, component stability, and post-polymerization properties of flowable composites.
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