Effect of diabetes mellitus on total amount of bone resorption in denture supporting tissue under continuous pressure

糖尿病对义齿支持组织骨动力学的影响尚未得到足够的研究。采用Wistar品系雄性链脲佐菌素诱导的糖尿病大鼠250只(n=50×5组)，采用骨组织形态计量学方法，研究糖尿病对义齿基托持续压力所致义齿基托下组织骨吸收的影响。在22周龄时将义齿基托应用于硬腭的磨牙区。在3个加载组中，义齿基托分别以1.0、10.0和20.0kpa的持续压力加载到腭部。在覆盖组中，义齿基托被设计为在没有任何机械压力的情况下与腭部接触。未戴义齿组未接受任何有意治疗。每隔3天或4天清洁上颌和可摘义齿基托。每组5只大鼠在义齿植入后间隔1周摘除腭部组织块。标本用Villanueva骨染色，甲基丙烯酸甲酯包埋，研磨至50um厚度。用二维图形分析系统计算腐蚀表面和破骨细胞表面。骨吸收量计算为：(A)~(B)；(A)覆盖组在义齿植入前12周内形成骨组织，(B)各骨吸收组骨吸收结束后在各个实验时段仍有骨组织存在，10.0和20.0kPa组分别在义齿植入后3周和4周观察到骨吸收。骨吸收总量10.0kPa组为60×16微米，20.0千帕组为87×17微米。与正常大鼠比较，糖尿病可延长骨吸收时间，增加骨吸收总量。

Effect of diabetes mellitus on bone dynamics in denture supporting tissue has not been investigated enough. The purpose of this study was to investigate the effect of diabetes mellitus on bone resorption in the tissues under denture base caused by continuous pressure exerted through denture base by using bone histomorphometry.Two-hundreds and fifty streptozotocin-induced diabetic male rats (n=50 X 5 groups) of Wistar strain were used in this study. Denture base was applied to the molar region of the hard palate at 22 weeks of age. In 3 loaded groups, the denture bases were designed to load a continuous pressure of 1.0, 10.0 or 20.0 kPa to the palate, respectively. In covering groups, the denture base was designed to contact with the palate without any mechanical pressure. The non-denture-wearing group received no intentional treatment. The cleansing of the palate and removable denture base was carried out at 3 or 4 days intervals. Palatal tissue block was excised from 5 rats of each experimental group after the denture insertion at one week interval. The specimens were stained with Villanueva bone stain, embedded in methyl-methacrylate, and ground to 50mum thickness. Eroded surface and osteoclast surface were calculated by using two dimensional graphic analysis system. Amount of bone resorption was calculated as (A) - (B) ; (A) Formed bone tissue during 12 weeks prior to the denture insertion in covering group, (B) Remained bone tissue after the end of bone resorption in each bone resorbed group at each experimental period.Bone resorption was observed in 10.0 and 20.0 kPa groups until 3 and 4 weeks after the denture insertion, respectively. Total amount of bone resorption was 60*16mum in 10.0 kPa group and 87*17mum in 20.0 kPa group. Comparing these results with results in normal rats in same condition as this study, it was showed that diabetes mellitus prolongs the term of bone resorption and increases total amount of bone resorption.