两种不同螺纹设计的牙种植体在犬颌骨中骨结合的对比研究

The effects of different thread designs on osseointegration of dental implants:a comparative experimental study in canine jaw

目的评价两种不同螺纹设计的牙种植体在比格犬下颌骨中不同时期的骨结合情况。方法选取纯种雄性比格犬4只,分别拔除双侧下颌第二前磨牙至第二磨牙,愈合12周。选择两种不同螺纹设计的牙种植体作为实验组和对照组,采取左右对照原则,每侧植入4颗相同种植体,埋入式愈合。术后2周和12周分别处死2只动物取材(n=8)。通过口内X线片和不脱钙硬组织切片进行放射线和组织学评估。结果X线片示两组种植体在不同时期的骨结合情况相似。组织学结果显示2周时植体与宿主骨主要为机械嵌合,种植体周围有少量新生骨形成;12周时种植体周围形成了大量矿化成熟的新生骨组织和骨小梁样结构。实验组和对照组种植体中段的骨结合率(bone-implant contact,BIC%)分别为(46.69±8.47)%和(36.71±13.72)%(2周),(67.27±7.46)%和(56.63±8.31)%(12周),两组间差异均无统计学意义。结论两种不同螺纹设计的牙种植体均能获得满意且相当的骨结合效果。

Objective To evaluate the osseointegration of dental implants with different thread designs in the canine mandible.Methods Four male beagle dogs were selected.Bilateral mandibular premolars and molars(PM2-M2)were extracted and allowed to heal for 12 weeks.The test group was a newly-designed dental implant,and the control group was AstraTech OsseoSpeed^(TM)TX dental implant.Four implants were implanted(submerged healing)on each side with a split-mouth design.Two animals were sacrificed at 2 and 12 weeks after surgery,respectively(n=8).Intraoral digital X-ray images and non-decalcified hard tissue sections were used for radiological and histological evaluations.Results Radiological images showed similar bone healing in two groups at 2 and 12 weeks after surgery.The histological results showed that at 2 weeks,implants were mainly mechanically inbuilt into the host bone,and a small number of new bones were formed around implants.At 12 weeks,a large number of completely mineralized new bones with the trabecular-liked structure was formed around implants.The bone-implant contact(BIC%)of the test and control group were(46.69±8.47)%and(36.71±13.72)%at 2 weeks,(67.27±7.46)%and(56.63±8.31)%at 12 weeks,respectively,and the difference between groups was not statistically significant.Conclusions Two dental implants with different thread shapes can achieve satisfactory and comparable osseointegration.