1993 Fiscal Year Final Research Report Summary
Study on Restorative Materials for Geriatric Dentistry - Light-activated Glass Ionomer -
| Project/Area Number |
04671184
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
補綴理工系歯学
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| Research Institution | Okayama University |
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Principal Investigator |
IRIE Masao Okayama University, Dental School, Assistant Professor, 歯学部, 助手 (90105594)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Geriatric society / Restorative materials / Study / Glass ionomer / Light-activated glass ionomer / Marginal leakage / Bonding / Setting shrinkage |
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| Research Abstract |
Effect of polishing period on marginal gap formation of commercially available glass ionomer restoration was investigated :
1. Marginal gap (either at enamel or at teflon cavity) of a light activated glass ionomer for restoration was determined immediately after light-activation, 1 day, 7 days following immersion in water. A conventional glass ionomer for restoration was used as control. Two glass ionomers had gaps of about 0.4 % at enamel and about 1 % at teflon cavities, immediately after light-activation or setting. Following 1 day immersion in water, marginal gap of two glass ionomers became significantly decreased. The gaps of light-activated glass ionomer were smaller than those of conventional one.
2. Effect of the polishing period on the gap width at the interface between the prepared tooth and the three light-activated glass ionomer restorative materials was determined. One light-activated glass ionomer analogous, one conventionally-cured glass ionomer restorative material and o
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ne light-cured composite were used as control. Restorations were made following by either polished immediately after the set or after 1 day immersion in water. The marginal gap width for all specimens polished following 1 day immersion in water was apparently smaller than those of immediately after the set. To reduce the marginal gap width, water absorption, increasing of the mechanical property and the bond ability to tooth structure would have a significant effect.
3. Effect of the polishing period on the gap between Class V cavity and light-activated glass ionomer, light-activated glass ionomer analogous and conventionally-cured glass ionomer restorations were determined. Restorations were made following by either polished immediately after the set or after 1 day immersion in water. Determination of gaps were made with axially sectioned specimens. Number of gaps for specimens polished following 1 day immersion in water was apparently smaller than those of immediately after the set. Polishing of these restorations after 1 day immersion in water is more beneficial for clinical practice. Less
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