微型种植体支抗愈合期稳定性的比较

目的比较不同愈合时间种植体支抗的稳定性。方法10只新西兰大白兔应用种植体60枚,均分为种植即刻组、种植后1周组、2周组、4周组、8周组进行拉出实验和转矩实验。采用单因素方差分析组间差异,相关性分析愈合时间、最大剪切力、最大力矩两两之间的相关性。结果4周与8周组最大剪切力分别为(179·68±24·65)N、(212·06±42·51)N;4周与8周组的最大力矩分别为(0·47±0·13)N·m、(0·61±0·16)N·m,与其他组相比差异均有统计学意义(P<0·05)。愈合时间、最大剪切力、最大力矩两两之间均呈正相关。结论4周是种植体愈合期生物稳定性的一个关键时间点。8周内种植体的生物力学性能与愈合时间呈正相关。     

Histological evidence concerning the osseointegration of titanium implants in the fractured rabbit femur

Stabilization of the broken bone is achieved using biocompatible materials. Since histology is still considered the gold standard technique for the assessment of bone formation around metallic implants, this report investigated the titanium implant integration in the accidentally broken bone in rabbits. The experimental protocol was reviewed and approved by the Ethical Committee of the Faculty of Medicine and Pharmacy Oradea, Romania. Holes were drilled in the diaphysis of the femur, and titanium implants were inserted in the created bone defect. In two subjects, fractures occurred on days two and three after the metallic alloy implantation. The other two rabbits presented no fractures following the surgical procedure. The rabbits were euthanized and the bones (with metallic implants) were harvested for histopathological investigation. Following decalcification, the bone samples were processed using the standard paraffin technique and stained by Goldner’s trichrome procedure. In subjects with a perfect immobilization of the titanium implants, the osseointegration occurred with minimal callus formation (i.e. primary cortical healing). In rabbits with bone fractures, the callus was more exuberant. A progressive replacement of the granulation tissue with hyaline cartilage and woven bone occurred soon after. The former aspects suggested an indirect metaplasia in the created callus. In all subjects, no inflammatory cells were identified in the created callus. The bone regeneration occurred either by primary cortical healing (in perfectly immobilized titanium implants) or by a process similar to the endochondral ossification (in poorly immobilized titanium implants following accidental post-implantation bones fracture).     

Effect of leukocyte and platelet rich fibrin (L-PRF) on stability of dental implants. A systematic review and meta-analysis

The aim of this study was to assess the impact, if any, of L-PRF application in an implant bed prior to implant placement, focusing on stability by means of implant stability quotient (ISQ) values. The literature was searched in a systematic way by means of the main databases and hand searching of the most relevant journals. The inclusion and exclusion criteria were used to determine the eligible studies included in this review. Only randomised controlled trials (RCT) and controlled clinical trials (CCT) were included. A total of four RCTs were included for data extraction. The risk of bias was deemed moderate to unclear. Meta-analysis was performed to assess the effect of L-PRF, on implant stability, immediately post-insertion in three studies, after one week from the implant placement in three studies and after four weeks for all the included studies. The fixed effects model has shown Hedges g statistic for the one week varying from 0.380 to 1.401 with a pooled figure of 0.764 (95% CI 0.443 to 1.085) and for four weeks varying between 0.74 and 1.1 with a combined effect of 0.888 (95% CI 0.598 to 1.177). The results for both intervals were in favour of the use of L-PRF while the statistical difference immediately post-insertion was not statistically significant. The present systematic review, though acknowledging its limitations, suggests that L-PRF has a positive effect on secondary implant stability and that needs to be correlated to the clinical practice to measure the actual clinical effect by means of reducing treatment times.     

荧光标记法比较4种表面处理方式种植体骨矿化沉积率的研究

目的荧光标记法观察比较4种表面处理方式种植体周围骨矿化沉积率的差异。方法微创拔除4只Beagle犬双侧下颌4颗前磨牙,待拔牙创愈合3个月后,植入奥齿泰种植体40颗,其中机械形态表面(ma-chined morphology,MM)组4颗,喷砂加酸蚀(sand blasted with alumina and acid etched,SA)组、可吸收性研磨介质(resorbable blasting media,RBM)组和生物化学喷砂酸蚀组(biochemistry sand blasted with alumina and acid etched,Bio-SA)组各12颗,愈合3个月,处死前13、14 d和3、4 d分别注射盐酸四环素和钙黄绿素,制取标本并置于70%酒精固定,采用塑料包埋技术制作骨磨片,荧光显微镜下观察,测量骨矿化沉积率。结果螺纹间及远离螺纹区域新骨矿化沉积率在4组间的差异均没有统计学意义(P>0.05);单独比较每组种植体螺纹间及远离区域骨矿化沉积率的差异性,RBM组及SA组组内差异没有统计学意义(P>0.05),而MM组和Bio-SA组组内差异具有统计学意义(P<0.05)。结论采用塑料包埋技术,通过荧光标记法能成功观察到新骨矿化沉积的情况;种植体植入3个月后,4种不同粗糙程度的种植体螺纹间及远离螺纹区域骨矿化沉积率没有差异性,而经机械形态表面处理的种植体和生物化学喷砂酸蚀处理的种植体,螺纹间骨矿化沉积比远离螺纹区域快。     

Surface Roughness of Dental Implant and Osseointegration

IntroductionDental implants are a usual treatment for the loss of teeth. The success of this therapy is due to the predictability, safety and longevity of the bone–implant interface. Dental implant surface characteristics like roughness, chemical constitution, and mechanical factors can contribute to the early osseointegration. The aim of the present article is to perform a review of the literature on surface roughness of dental implant and osseointegration.MethodologyThis work is a narrative review of some aspects of surface roughness of dental implant and osseointegration.ConclusionDespite technological advancement in the biomaterials field, the ideal surface roughness for osseointegration still remains unclear. In this study about surface nanoroughness of dental implant and osseointegration, the clinical relevance is yet unknown. Innovative findings on nanoroughness are valuable in the fields of dental implantology, maxillofacial or orthopedic implant surfaces and also on cardiovascular implants in permanent contact with patient’s blood.