预防性根尖封闭后自体移植牙的临床和根尖周愈合评估

Clinical and Periapical Healing Assessment of Autograft Teeth after Prophylactic Apical Closure

目的:探究预防性根尖封闭对自体移植牙的根尖周愈合的影响。方法:3条比格犬随机纳入24颗前牙,分对照组、RCT组(术中根管治疗)、Ref组(术中截根,倒封闭根尖),n=8。移植术后1、4、12周评估移植牙松动、脱落数和影像学指标;术前、术后4、12周记录探诊深度。12周后,对样本进行Micro CT扫描[计算骨体积分数比值(bone volume/tissue volume,BV/TV)、骨小梁分离度(trabecular separation,Tb.Sp)、骨小梁数目(trabecular number,Tb.N)、骨小梁厚度(trabecular thickness,Tb.Th)]和苏木精-伊红(hematoxylin-eosin,HE)染色。对量化松动度、探诊深度(probing depth,PD)值和Micro CT结果进行分析统计。结果:对照组和Ref组脱落2颗牙,RCT组脱落1颗,平均松动度受时间和分组影响显著(P<0.05)。PD值的下降与时间显著相关(P<0.05),RCT组和Ref组显著低于对照组;X线片中,牙槽骨高度随骨改建逐渐降低,对照组部分牙根出现外吸收。RCT组的Tb.Sp明显低于对照组(P<0.05)。对照组的Tb.N明显低于其他两组(P<0.05,P<0.01);RCT组和对照组牙根表面见浅表性吸收,Ref组的根尖组织致密,牙周层次清晰;RCT组根尖组织排列疏松。结论:预防性根尖封闭在自体移植牙中具有效性,可简化术后治疗,促进自体移植牙周骨重建,因此是对自体植牙术的有效改良。

Objective:To evaluate the effect of apical surgery on autotransplantation teeth from three perspectives:clinic,image,and histology.Methods:Twenty-four teeth of three beagle dogs were randomly divided into a control group,an RCT group,and a Ref group(transplantation after root-end filling treatment).Clinical and image examinations were performed at 1,4,and 12 weeks after surgery.Samples were subjected to micro CT scanning(calculated BV/TV,Tb.Sp,Tb.N,Tb.Th)and HE staining.Analytical statistics were performed to quantify loosening,PD values,and micro CT results.Results:Several teeth were lost in the three groups,and there was an improvement in the looseness at 12 weeks postoperatively.Mean loosening was significantly influenced by time and group(P<0.05).The decrease in PD values was significantly associated with time(P<0.05)and was significantly lower in the RCT and ref groups than that in the control group.In X-ray films,alveolar bone height was gradually decreased with bone remodeling,and some roots in the control group showed external resorption.The Tb.Sp in the RCT group was significantly lower than that in the control group(P<0.05).The Tb.N in the control group was significantly lower than those in the other two groups(P<0.05 and P<0.01).The apices of the Ref group were more closely related to the physiological structure and exhibited active bone repair confirmed by histology.Conclusion:Prophylactic apical sealing is effective in autograft teeth,which can simplify postoperative treatment and promote periodontal bone reconstruction of doner teeth.Accordingly,it is an effective modification of RCT for autografted teeth.