合力在离体牙实验性楔状缺损形成中的作用

The effect of occlusal force on the formatlon ofexperimental cervical weilge-skaped defects on humanteeth

本研究通过对不同因素所致离体人牙实验性楔状缺损的深度和形态变化的检测，探讨了力因素在楔状缺损形成的作用。将７名患者的９对离体双尖牙按不同力因素分成三组，各组牙齿仅颊侧牙颈部接受横刷牙实验，分别在ｐＨ５和７水浴条件下交替进行模拟力疲劳和横刷牙实验。分为四次间隔，总共进行１６０００００击力疲劳和８０００００回横刷牙实验。在各间隔期，用ＳｅｅＳｃａｎ计算机图象分析仪测量受试牙复制模型颈部缺损侧影的深度并记录缺损形状。结果证明，力在人牙实验性颈部楔状缺损形成过程中起重要作用。单独的力因素可非常缓慢地致牙颈部缺损，当横刷牙和酸蚀共同作用时，颈部缺损深度显著增加，并形成楔形缺损。

AbstractNine pairs of premolar from 7 patients were dividedinto three groups according to different eeclusal forces.Every tooth was tested with PHS or PH7 water bath byan electric toothbrushing machine and an electric oc-clusal force fatigue machine alternatively- Only the buc-cal surface of every tooth suffered from brushing test.There were 600 000 strokes of occlusal force fatigue testandlor 800 000 cycles of cross-brushing test for everytcoth throughout the experiment with 4 intervals. Dur-ing every interval, the depth at the profile of the cervi-cal defect on each replica of tested tooth was measuredand the shape of every defect was recorded with a computerital Seescan image analysis system. The findingssuggested that the occlusal force played an importantrole in the forniation of experimental cervical wedge-shaped defects. theclu.cal force alone could produce cervical tcoth defect in very slow rate. When the occlusalforce associated with acid erosion and tcoth-brushingabrasion, the depth of cervical defect increased signifi-cantly and the wedge-shaped defects were formed.