微型钛钉种植体支抗压低犬上前牙过程中牙周组织骨保护素的表达

背景:在微型钛钉种植体支抗压低上前牙过程中,骨保护素可否发挥抑制骨吸收的作用,尚不十分清楚。目的:观察微型钛钉种植体支抗压低犬上前牙过程中牙周组织骨保护素的表达变化。方法:9只犬分为5组,对照组未加正畸装置,于实验开始时处死;其余各组在上颌两侧第二切牙和第三切牙牙根之间唇侧的牙槽间隔处植入微型钛钉种植体作为支抗,每侧施加100g的牵引力压低上颌两侧第一和第二切牙,分别于加力后1,2,4,12周(主动加力4周,撤力后保持8周)处死。选择一侧第一和第二切牙连同牙龈、牙槽骨完整切取,进行牙周组织内骨保护素的免疫组化染色。结果与结论:牙周组织中骨保护素的表达在加力1周后开始增加,2周达最高峰,其后开始下降,4周后回落接近正常水平。12周后(撤力8周后),骨保护素阳性细胞数量少量回升,统计结果显示与加力4周后以及未加力时差异无显著性意义。提示微型钛钉种植体支抗压低犬上前牙过程中,骨保护素参与了牙周组织的改建,并随时间的改变,呈动态变化过程。

Osteoprotegerin expression changes in the periodontal tissue following titanium-alloy miniscrew as anchorage for the maxillary incisors intrusion

BACKGROUND:Osteoprotegerin(OPG) inhibits osteoclast(OC) formation and differentiation and increases bone density.It is a key factor for inhibiting bone resorption.However,the precise mechanism of OPG remains unclear following mini-implant anchorage for the maxillary incisors intrusion.OBJECTIVE:To observe the expression of OPG in the periodontal tissue following the mini-implant anchorage for the maxillary incisors intrusion.METHODS:Nine dogs were selected and randomly divided into 5 groups:Ⅰ group was control group,including 1 dog with no force given;Ⅱ,Ⅲ,Ⅳ,Ⅴ groups contained 2 dogs respectively.Mini-implants were inserted into the labial alveolar bone between the roots of maxillary the second and the third incisors on both sides;100 g force was imposed on the first and the second incisors on both sides.At the end of 1,2,4,12 weeks(activation for 4 weeks,then retention for 8 weeks after force removal),the animals were sacrificed,the first and second incisor teeth on the one side were randomly selected and these teeth with gums,alveolar bone tissue were completely cut.Then expression of OPG in periodontal ligament(PDL) was inspected by using immunohistochemistry.RESULTS AND CONCLUSION:Expression of OPG in the alveolar bone and periodontal ligament tissues increased at 1 week after force given,reached maximum at 2 weeks after activation,and then dropped to normal level at 4 weeks after activation.After 12 weeks(activation for 4 weeks,then retention for 8 weeks after force removal),it increased insignificantly,which did not differ from that at 4 weeks after activation and the control group.OPG participated in the reconstruction of periodontal tissues and dynamically changed along with time following mini-implant anchorage for the maxillary incisors intrusion.