1999 Fiscal Year Final Research Report Summary
Clinical Investigation for Long-term Performances of Restorations and Establishment of Criteria for Replacement
| Project/Area Number |
09307046
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Conservative dentistry
|
|---|
| Research Institution | Tsurumi University |
|---|
Principal Investigator |
NAKAMURA Jiroh Tsurumi University, School of Dental Medicine, Professor, 歯学部, 教授 (90064336)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IWAKU Masaaki Niigata University School of Dentistry, 歯学部, 教授 (70013927)
TAGAMI Junji Tokyo Medical and Dental University, Professor, 歯学部, 教授 (50171567)
KOHNO Atsushi Tsurumi University, School of Dental Medicine, Professor, 歯学部, 教授 (00064345)
SHINTANI Hideaki Hiroshima University School of Dentistry, Professor, 歯学部, 教授 (80034239)
KATOH Yoshiroh The Nippon Dental University, School of Dentistry at Niigata, Professor, 新潟歯学部, 教授 (20060452)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Keywords | Clinical Evaluation / Long-term Restoration / Posterior Resin Composite / Clinical Criteria / Marginal Adaptation / Marginal Fracture / Adhesion / Abrasion Abrasion |
|---|
| Research Abstract |
In this project we overlooked all the literatures recent ten years that reported about clinical performances of dental restorations and we accomplished the following clinical researches. Tagami and Inai reported that main reasons of 1051 direct composite restorations were 46.5% for original caries and 34.0% for secondary caries. Iwaku and Fukushima reported that 116 self-cured direct composite restorations filled in occlusal areas showed 71% functional survival rate after ten years and also the average relative wear at margins were under 100μm. Those results indicated that direct composite restoration even in posterior occlusal area was clinically acceptable for ten years. Shintani reported from his 13-year clinical observation of direct composite restorations that-marginal integrity, sulface wear, discloration and staining did not remarkably change at each period of time, 4, 7 and 10 years. However after 13 years those obviously changed and secondary caries also increased slightly. Ku
… More
bo reported that 75 cases out of 310 direct composite restorations were replaced. The average period until replacement was 6.2 years, however there was significant difference between 7.4 years for class III and 4.5 years for class V. Fukushima and Kubo commented that three main reasons of replacement were pulp irritation, fracture and failure. Kubo also reported that there was no significant difference of clinical performance between two bonding systems, Clearfil LinerBond II and Single Bond when used in 66 direct composite cases of wedge shaped defect. Kohno and Takamizu suggested with their 7-year clinical data of direct composite that restorations placed with self-etching bonding system could survive at least for 7 years. Kato and Shinkai recommended from their 5-year investigation of posterior composites that marginal bevel should be placed only in small area on the edge of occlusal groove and occlusal transparent matrix should be used. Inoue and Kitano emphasized the importance of field control and high quality of restoring technique to accomplish better long-term clinical results for direct composites. Komatsu focused on the gap width of restorations to make decision of replacement. He suggested that the gap width over 50 μm could be perceptive with dental explorer and evaluations under high magnification was mandatory. Kubo reported that 21 out of 100 cast restorations were replaced and the average functional period of time was 6.3 years. Takeshige evaluated the margines of ceramic inlays for 8 years with SEM. He suggested that the most important factor for the retention of brittle ceramic inlay was the minimization of small flaw and micro crack in the process of fabrication. Less
|
