アブストラクト（19巻3号：神奈川歯学）

神奈川歯学

Japanese

Title　： 臼歯部用コンポジットレジンの機械的特性 - とくに修復物辺縁にみられる初期破折に関連して -
Subtitle　： 原著
Authors　： 澤悦夫, 中嶋正, 青野忠之, 鈴木淳子, 前川彰男, 久保田顕正, 花岡孝治, 杉崎新一郎, 嶋村嘉明, 岩本次男
Authors（kana）　：
Organization　： 神奈川歯科大学保存学教室第一講座
Journal　： 神奈川歯学
Volume　： 19
Number　： 3
Page　： 269-279
Year/Month　： 1984 / 12
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「緒言」臼歯部咬合面の実質欠損に対する修復法として頻用されて来たアマルガム修復法に代わり, 近年, コンポジットレジンの臼歯部への適用が試みられ, その臨床的有用性が論議されている. とくに本邦においてはアマルガム修復法に関わる水銀による環境汚染が重要な社会問題として取り上げられている現状から, アマルガムに代わるべき修復材料としての臼歯部用コンポジットレジンの出現が期待され, この数年間に数種の製品が開発され, 日常の臨床に使用されている. しかしながら, 本修復法に対しては, 窩洞形態あるいは修復操作法などの基本が未だ十分に確立されていないのが現況であるため, 修復物の予後に関してもそれらの臨床的評価は多様であり, それ故, 材質の改良はもとより, 窩洞形態や臨床技法の細部にわたる適切な指針が早急に提示されることが切望されている. とくに材質的に改良されるべき第一の点として, 辺縁封鎖性に関与する機械的性質の向上が挙げられる.
Practice　： 歯科学
Keywords　：

English

Title　： Mechanical Properties of Posterior Composite Resins in Relation to Marginal Fracture of Restorations
Subtitle　：
Authors　： Etsuo SAWA, Nori NAKAJIMA, Tadayuki AONO, Junko SUZUKI, Akio MAEKAWA, Akimasa KUBOTA, Koji HANAOKA, Sinichiro SUGISAKI, Yosiaki SIMAMURA, Tsugio IWAMOTO
Authors（kana）　：
Organization　： Department of Restorative Dentistry, Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 19
Number　： 3
Page　： 269-279
Year/Month　： 1984 / 12
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： Composite resin is now widely used in clinical practice for restoring anterior teeth and is recently getting appled to posterior teeth in place of silver amalgam alloy. However, the toughness of the posterior composite resin when it is subjected to occlusal stress has not so much been clarified, though the importance of edge strength for posterior restorative materials have particularly been emphasised. In the first part of the present study, the mechanical properties including fatigue strength of four posterior composite resins (P-10, Bellfirm P, Clearfil Posterior and Microrest Jar Type) were determined and compared with those of conventional composite resin (Adaptic). Both compressive and tensile tests were performed in accordance with ADA Specification No.27, and the testing method described in ISO Specification No.4049 was applied for the three-point bending test. Fatigue test was also carried out by using the special testing device developed by author's laboratory and the fatigue strength of each specimen was recorded as the number of loading cycles at the time when the specimens were fractured by repeating load. On the basis of results from laboratory tests, the clinical study was undertaken as the second part of this report. Seventy-five posterior teeth with occlusal carious lesions or class I defective restorations were selected and restored randomly with four posterior composite resins used in laboratory tests. Conventional composite resin (Adaptic) and high copper amalgam alloy (Spherical D) were also tested as the control. After finishing of the restorations, impression were taken for making replica of the restored tooth surface and the replications were repeated at one week, and 1, 3 and 6 months after completion of restoration. These replicas were observed by SEM and photographed, and then marginal integrity of restorations were evaluated by five examiners. From the experiments described above, the following results were obtained. 1) As to compressive strength, four posterior composite resins showed approximately the same values of about 3,400Kg/cm2 and they were almost doubled to that of Adaptic. 2) In diametral tensile and transverse strength, not so much difierences were found among materials tested including Adaptic, although a little difference was observed between two materials (P-10 and Clearfil Posterior) and others in tensile strength. 3) On the contrary, the fatigue strength of Adaptic was approximately the same as that of P-10 and other posterior composite resins showed the lower strength, particularly, both values of Microrest Jar Type and Bellfirm P were nearly a quarter. 4) In the clinical study, deteriorations of marginal integrity were observed around the restorations with Bellfirm P and Microrest Jar Type aged one month, and with P-10 and Clearfil Posterior aged three months. The similar deteriorations of marginal area to those of amalgam restorations were found in all cases aged six months. 5) It was confirmed that the marginal degradation of restoration with Adaptic was not due to fracture but mainly due to abrasion by means of observing the longitudinal sections of replica. 6) Higher correlation coefficients were obtained between the mechanical properties except compressive strength and the degree of marginal integrity of restorations with posterior composite resins tested aged one and three months.
Practice　： Dentistry
Keywords　：