Er∶YAG激光根尖切除断面形貌对牙周膜细胞生长的影响

The effects of apical dentin surface morphology made by Er∶YAG laser cut on the growth of periodontal ligament cells

目的:观察Er∶YAG激光根尖切除断面的形态对牙周膜细胞生长的影响。方法:将66颗离体单根前磨牙随机分为3组(n=22),在距离根尖3 mm处垂直于牙长轴切除根尖形成断面样本,A组使用高速涡轮金刚砂车针,B组使用超声骨刀,C组使用Er∶YAG激光。SEM观察牙根断面残屑、玷污层、牙本质小管、裂隙等情况并测算粗糙度后,将牙周膜细胞接种于各组根片表面进行培养,分别于24、48、72 h时用CCK-8法检测样本表面细胞增殖情况。结果:A组操作时间显著短于B组和C组(P<0.01)。SEM观察显示,C组牙根断面几乎没有残屑、玷污层,可见牙本质小管,A组、B组可见碎屑及玷污层,A组未观察到牙本质小管。3组牙根断面均可见到裂隙,C组的裂隙数目较少。C组牙根断面粗糙度均值为(1487.13±295.90)nm,显著高于A组和B组(P<0.001)。CCK-8法显示,细胞接种于根面24、48、72 h后,各组的细胞数量(A值)均随培养时间的增加而增加,其中C组细胞增殖最明显,48 h和72 h时C组显著高于其他两组(P<0.05)。结论:Er∶YAG激光根尖切除断面形态比超声骨刀和高速涡轮金刚砂车针根尖切除更利于牙周膜细胞在其表面生长。

Objective:To study the effects of the apical dentin surface morphology resected with Er∶YAG laser on the proliferation of human periodontal ligament cells(hPDLCs).Methods:66 single premolars were randomly divided into 3 groups(n=22),and the apical root slices were made by resection perpendicular to the root long axis 3 mm from the apex using high-speed handpiece(group A),piezosurgery(group B)and Er∶YAG laser(group C),respectively.SEM was used to observe the apical dentin surface in the aspects of debris,smear layer,dentinal tubules,cracks,ablation characteristics and the dentin surface roughness was measured.hPDLCs were clutured on the surface of the slices of the groups,CCK-8 method was used to detect cell proliferation on the samples at 24,48 and 72 h of culture,respectively.Results:The surface preparition time of group A was shorter than that of group B and C(P<0.001).SEM observation showed that in group C,there was no residual debris or stained layer,and dentin tubule was visible on the dention surfaces.Detritus and stained layers were observed in group A and B,and dentin tubule was not observed in group A.Cracks were observed in all the groups,but less in group C.Roughness(nm)of group C(1487.13±295.90)was higher than that of group A and B(P<0.001).CCK-8 assay showed that the cell proliferation(A value)of all groups increased gradually with the culture time after 24,48 and 72 h of hPDLCs seeded on the root surface.And the cell proliferation in group C was the most significant than that in group A and B(P<0.05)at 48 and 72 h.Conclusion:The morphological performance of the apical dentin surface resected with Er∶YAG laser is more conducive to hPDLCs growth than that with the ultrasound and burs.