不同角度机械力刺激后犬种植体周围龈沟液中骨保护素的表达

Osteoprotegerin expression in the peri-implant sulcus fluid after mechanical stimulations at different angles

背景:由于局部解剖结构的限制,临床上往往采用15°-30°角度基台进行种植义齿修复,在受到过大角度机械力损伤的条件下,种植体周围组织界面的结构特点决定了其抵御口腔环境中病原微生物侵袭的能力较天然牙差。目的:研究犬下颌骨种植体受到0°和30°角100 N持续机械力作用后,种植体周围龈沟液中核因子κB受体活化因子配体和骨保护素水平的改变。方法:将6只杂种犬随机均分为3组,拔除双侧下颌第二前磨牙,每侧植入2颗牙种植体,3个月后行钴铬烤瓷冠修复,修复1周后其中2组分别施以0°角100 N、30°角100 N机械力,每次5 s,共10 min;对照组未受机械力作用。机械力作用24 h、72 h、1周后,获取各组种植体周围龈沟液样本,应用ELISA方法检测样本中核因子κB受体活化因子配体和骨保护素的水平。结果与结论:随时间的延长,0°角100 N组、30°角100 N组种植体周围龈沟液核因子κB受体活化因子配体水平均逐渐升高,均高于对照组(P<0.05,P<0.01),并且30°角100 N组增加更明显;至1周时稍降低,但仍高于对照组(P<0.05,P<0.01)。随时间的延长,0°角100 N组、30°角100 N组种植体周围龈沟液骨保护素水平均逐渐降低,均低于对照组,但仅30°角100 N力组与对照组比较差异有显著性意义(P<0.05);至1周时稍升高,但还是低于对照组,30°角100 N力组与对照组比较差异有显著性意义(P<0.05)。说明当种植义齿受到30°角100 N连续机械力作用后,种植体周围龈沟液中可检测到破骨活动增强,建议临床上种植义齿的牙合力尽量与种植体植入的方向一致。

BACKGROUND：Because of the limitation of local anatomical structure, 15° to 30° angled abutments are commonly used for implant restoration. Under the condition of oversized angle mechanical force, the ability of the dental implant to resist invasion of patho-microorganism is poorer than natural teeth, which is decided by the structural characteristics of peri-implant tissue interface. OBJECTIVE：To study concentration changes of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand （RANKL） from peri-implant sulcus fluid of cranine mandibular implants under 100 N forces at 0° and 30° angle. METHODS：Six dogs （18 dental implants） were randomly divided into three groups： group A, 100 N 0° group, group B, 100 N 30° group, and group C, non-mechanical stimulation group （control group）. The second premolars of the bilateral mandible were extracted, and two dental implants per side were implanted. Cobalt-chromium PFM ful crown was used for tooth restoration 3 months later. After 1 week of ful crown restoration, under general anesthesia of 5% odium pentobarbital, 100 N was given verticaly （0° angle） and at 30° angle, and once worked for 5 seconds on implants, totaly 10 minutes. After 24 hours, 72 hours and 1 week of mechanical force, samples of groups A, B and C were colected from the peri-implant sulcus fluid, and ELISA method was used to detect RANKL and osteoprotegerin levels. RESULTS AND CONCLUSION：After application of 100 N mechanical force verticaly, the RANKL level in the peri-implant sulcus fluid increased obviously at 24 hours, increased continuously at 72 hours, and decreased slightly at 1 week, and there was statisticaly significance compared to the non-mechanical stimulation group （P 0.05）. The osteoprotegerin level in the peri-implant sulcus fluid declined gradualy over time after 100 N mechanical stimulation at 30° angle, and there was statisticaly significance compared to the non-mechanical stimulation group （P 〈 0.05）. The results indicate that there are increased bone destructive activities from the peri-implant sulcus fluid under 100 N mechanical stimulation at 30° angle, and it is recommended that the occlusion force works along the direction of dental implant axis clinicaly.