2000 Fiscal Year Final Research Report Summary
New Method for Testing of Accelerated aging of Resin-Dentin Bonds
| Project/Area Number |
10671796
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | Kyushu Dental College |
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Principal Investigator |
SHONO Yasuo Kyushu Dental College, Assistant Professor, 歯学部, 講師 (40187505)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Microtensile test / Non-trimming microtensile test / Bonding system / Dentin Bonding / Tensile bond strength |
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| Research Abstract |
The durability of resin-dentin bonds is of vital importance if composite resins are to be successfully used as esthetic restorations over long time periods. In the conventional bond strength test, some investigators (Burrow et al., 1996) reported that it may take as long as 3-5 years for the adhesive to slowly hydrolyze. However, within that 3-5 year period, the tested adhesive products are usually superceded by a new generation of products. It would be desirable to develop an accelerated aging model that could challenge the durability of resin-dentin bonds in a relatively short period of time. One approach to this is to divide bonded specimens into 1 x 1 x 8 mm beams as described above. We speculated that such a specimen might provide a useful method of accelerating whatever hydrolysis of resin-dentin bonds might occur over time (Shono et at., 1998). The purpose of this study was to test the feasibility of using small (ca. 1 x 1 x 8 mm) beams of resin-bonded dentin specimens to evaluate the durability of resin-dentin bonds by studying microtensile bond strength over a 3-month period of incubation at 37。C.As the results, There were no significant differences in the bond strengths of either wet-bonding system of One-Step (Bisco, USA) or self-etching primer system of Clearfil Liner Bond II (Kuraray, Japan) to superficial vs. deep dentin at 1 day but at 90 days, their bond strengths to deep dentin had fallen significantly (p<0.05). The division of large specimens into many small beams accelerate the deterioration of bond strength in deep dentin in all bonding systems. The newly developed test method is very useful for evaluating regional tensile bond strength tests across entire bonded surfaces. This type of information is much more meaningful than the single measurements made with conventional resin composite bond strength tests.
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