不同力值下牙移入牵张成骨新骨内牙周组织改建的对比性分析

Comparative Analysis of Periodontal Tissues Reconstruction of Tooth Moved into Regenerated Bone under Different Distraction Forces in Dogs

目的研究不同力值作用下牵张成骨区内实验牙龈沟液(gingival crevicular fluid,GCF)中天冬氨酸转氨酶(aspartate aminotransferase,AST)动态变化。方法将8只Beagle犬依据牵张成骨后移动实验牙所用力值分为50 g组和100 g组,每组4只。各组右侧以相应力值将实验牙向远中位置移进骨再生区域,将各组左侧设置为研究对照,不予加力。对比分析加力各时点(加力前、后、1d、2d、3d、7d、14d、28d)实验牙GCF中AST动态变化。结果各组不同时点实验牙GCF中AST动态变化明显(P<0.01),各组近远中侧的GCF中AST动态变化明显(P<0.01);受力后50 g组与100g组表现为下降趋势,在21 d回归为基线水平;受力后24 h,100 g组的AST表现为下降趋势,在7 d后表现为低水平维持;予以定时分析发现,100 g组AST在基线水平趋势以下维持当21 d时可呈恢复表现,但随后又呈上升趋势。结论在实施牵张成骨治疗患者的牙周组织以及细胞中,AST的活性改变及分布,同正畸力的施加时间、大小、作用部位高度相关。AST在施加100 g力时,AST波动变化呈稳定状态,能为临床判定正畸加力预期效果提供重要参考。

Objective To study the dynamic change of aspartate aminotransferase （AST） in osteogenesis tooth gin- gival crevicutar fluid （GCF） of different distraction effects. Methods Eight Beagle dogs were divided into 50 g group and 100 g group according to the distraction forces. Experimental teeth at the right side were transplanted into the bone regen- eration area with the corresponding stress values and teeth at the left side were as control and untouched. Dynamic AST changes in GCF at different timepoints （before distraction, 1 d, 2 d, 3 d, 7 d, 14 d and 28 d after distraction） were compared. Results AST in the experimental teeth in each group at different timepoints and in distal side of GCF changed significant- ly （P^0. 01）. After the stress,50 g group and 100 g group showed a downward trend and returned to the baseline in the 21 d. 24 h after stress,AST decreased in 100 g group and maintained at the low level at 7 d. Timing analysis indicated that AST in 100 g group maintained at baseline trend and recovered at 21 d and then increased. Conclusion In the periodontal tissue and cells with the distraction osteogenesis, activity and distribution of AST are highly related with the tension value of applying time, size and action site. The AST fluctuation is stable under 100 g force,which can be used as a clinical index of bone boosting.