Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants|
|Research Institution||Tokyo Medical and Dental University|
TAGAMI Junji TMDU,Operative Dentistry, professor, 歯学部, 教授 (50171567)
NAKAJIMA Masatoshi TMDU,Operative Dentistry, lecturer, 歯学部, 助手 (50272604)
INAI Norimichi TMDU,Operative Dentistry, senior lecturer, 歯学部, 講師 (70232501)
NIKAIDO Toru TMDU,Operative Dentistry, senior lecturer, 歯学部, 講師 (00251538)
OTSUKI Masayuki TMDU,Operative Dentistry, associate professor, 歯学部, 助教授 (30203847)
佐野 英彦 東京医科歯科大学, 歯学部, 講師 (90205998)
猪越 重久 東京医科歯科大学, 歯学部, 助教授 (60143583)
山田 敏元 東京医科歯科大学, 歯学部, 助教授 (40134712)
|Project Period (FY)
1996 – 1998
Completed(Fiscal Year 1998)
|Budget Amount *help
¥20,800,000 (Direct Cost : ¥20,800,000)
Fiscal Year 1998 : ¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1997 : ¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1996 : ¥15,000,000 (Direct Cost : ¥15,000,000)
|Keywords||Resin bonding system / Dynamic 3-D analysis / Scanning laser microscope / Er : YAG laser / Caries affected dentin / Cervical abraded dentin / Clinical factor / マイクロテンサイル試験 / 齲触象牙質 / ウエットボンディング法 / レジンセメント / Er : YAGレーザー / セルフエッチングプライマー / 齲蝕象牙質 / リン酸エッチング / 間接法コンポジットレジンインレー修復 / マイクロテンサイルボンド法 / エナメル質 / 象牙質 / 接着性レジン / 歯面処理 / う蝕象牙質|
1. Bond strength to affected dentin
It was revealed that bond strengths of some resin bonding systems to several types of dentin surfaces affected by cervical abrasion, caries and laser irradiation showed lower bonds than those of normal dentin.
2. Dynamic 3-D analysis of etched dentin surfaces
Topography of wet and dried etched dentin surface was observed under a laser scanning microscope. Dentin surface etched with phosphoric acid showed shrinkage after air drying. The method that prevents shrinkage of etched collagen is ideal for sufficient penetration into demineralized dentin layer.
3. Re-evaluation for the bonding performance to enamel
It was indicated that etching depth of phosphoric acid was 40 times greater than that of self etching primer. Thus, it was suggested that multiple application of self etching primer in the clinical situation. And, it was confirmed that the bond strengths to intact enamel surfaces were lower than those to ground enamel surfaces.
4. SEM observation of bond
There was no correlation between the thickness of the hybrid layer and tensile bond strength. It can be considered that the mechanical properties of hybrid layer is more accessible to bond strength than its thickness.
5. Clinical factors influencing dentin bonding
It was demonstrated that clinical factors (e.g. temperature, humidity, residues of temporary filling materials and endodontic treatment) influence the bond strengths of adhesive resin systems and resin luting cements to dentin.
6. Bonding performance of composite resin inlays
The bond strength of resin composite inlay to dentin was lower than that of resin composite for direct restoration. However, the bond strength indicated higher value when resin coating method was used.
Consequently, it was proved that the properties of hybrid layer and bond strength varied because of the difference of composition and structure of dentin and several clinical factors. More research will be needed to confirm the optimal restorative procedures. Less