@article{oai:niigata-u.repo.nii.ac.jp:00025959,
 author = {Ishikawa, Kazuyuki and Fukushima, Masayoshi and Iwaku, Masaaki},
 issue = {1},
 journal = {新潟歯学会雑誌, 新潟歯学会雑誌},
 month = {Aug},
 note = {The effects of mechanical cyclic loading on marginal leakage of posterior composite restorations were evaluated using cyclic loading machine which simulated mastication. Three types of class I cavities were prepared in extracted human molars : un-based wide type, fully-based wide type and un-based narrow type. After placing chemically-cured and light-cured composite resins, specimens were occlusally subjected to mechanical cyclic loading parallel to the axial direction in an aqueous solution of 0.2% basic fuchsin. Marginal leakage was evaluated on the bucco-1ingually-Sectioned surfaces under a stereo microscope. Marginal leakage was significantly greater in the 1.3kg, 24hours (1.4×10^5 cycles) cyclic loading group in comparison with control group. However, no statistical difference was observed between 1.3kg, 24hours loaded group and more loaded group. Light-cured composite restorations showed superior sealing ability immediately after placement, when compared with those which were chemically-cured, while, both types of composite restorations showed good sealing ability when a load was applied after soaking the restored teeth in water one week. Neither cavity size nor the presence of a cement base had any appreciable effect on marginal leakage. These results indicated that the application of cyclic loading to simulate mastication appeared to be of significance for evaluation of marginal sealing accompanied by the strain or distortion of tooth and restorative materials in posterior restorations., 口腔の咀嚼に近似した繰り返し荷重試験機を用いて,繰り返し荷重が臼歯用コンポジットレジン修復物の辺縁封鎖性に及ぼす影響について検討した｡ヒト抜去大臼歯に3種の1級窩洞,すなわち無裏層大型窩洞,裏層大型窩洞および無裏層小型窩洞を形成し,各種接着性コンポジットレジンを通法通り充填した｡次いで,0.2%塩基性フクシン水溶液浸漬下で修復歯の咬合面より歯軸に平行に繰り返し荷重を加え,歯牙を頬舌方向に切断後,実体顕微鏡下で切断面における辺縁漏洩度をスコア評価した｡その結果,1.3Kg,24時間(98回/分)荷重を加えた群の辺縁漏洩度は対照群と比較して有意に増大した｡しかしながらそれ以上荷重の大きさおよび回数を増加させても漏洩度に有意差は認められなかった｡充填直後に荷重を加えた場合,化学重合型コンポジットレジンは高い漏洩度を示したのに対し,光重合型コンポジットレジンは優れた辺縁封鎖性を示した。一方,1週間水中浸潰後荷重を加えた場合は両コンポジットレジンともに低い漏洩度を示した｡窩洞形態別では大型窩洞と小型窩洞の間で,また裏層の有無で辺縁漏洩度に有意差は認められなかった｡以上の成績から,咀嚼を模した繰り返し荷重試験は修復物の変位変形に伴う辺縁封鎖性を検討する上で意義ある試験法であることが明らかとなった｡},
 pages = {9--16},
 title = {Effect of mechanical cyclic loading on marginal leakage of posterior composite restorations},
 volume = {25},
 year = {1995}
}