种植体表面活化修饰对其周围骨缺损愈合的影响

The influence of chemically-modified SLA on bone defect healing around implants in dogs

目的:研究种植体表面化学活化处理对种植体周围骨缺损愈合的影响。方法:采用6只成年Beagle犬,拔除下颌双侧前磨牙和第一磨牙3个月后行种植体植入术,在下颌第三前磨牙(P3)和第一磨牙(M1)部位常规制备直径2.8mm、深10mm的孔洞,其冠方5mm区域进一步扩孔制备成直径5.3mm的种植窝。每侧下颌骨植入直径3.3mm、长10mm的modSLA(化学活化大颗粒喷砂酸蚀)和SLA(大颗粒喷砂酸蚀)种植体各1颗,形成种植体冠方深5mm、宽1mm的环形骨缺损。双侧共植入4颗种植体,采用非埋入式愈合方式。术后2周、4周和8周时收获含种植体的骨组织标本,制成切片后,经苦味酸品红染色,检测骨结合率(BIC%)、新骨填充率(NBF%)以及新骨与种植体接触的最冠方水平至缺损底部的距离(B-D)。应用SPSS13.0软件包对数据进行分析。结果:观察期内无种植体松动脱落。3个时间段内,2组种植体周围的骨缺损区域皆有新骨生成,新骨形成始于缺损区的根方和侧方骨壁。2周和4周时,modSLA种植体的BIC%、NBF%和B-D值显著高于SLA种植体的相应指标值(P<0.05);8周时,2组之间无显著差异(P>0.05)。结论:化学活化表面处理方式有利于促进种植体周围骨缺损的早期骨愈合。

PURPOSE： The study was designed to investigate the effect of surface chemical modification on the process of bone defect healing around implants in dogs. METHODS： Six Beagle dogs were used in this study. The mandibular premolars and first molars were extracted bilaterally. Three months after tooth extraction the procedure of implant placement was performed. Four canals with a diameter of 2.8mm and 10mm in depth were prepared at the third premolar （P3） and the first molar （M1） sites of both sides of the mandible, of which the coronal 5mm portion were further widened with the 5.3mm diameter twist drill. In each side of the mandible one modSLA （chemically-modified SLA） implant and one SLA （sandblasted, large-grit, acidetched） implant with a diameter of 3.3mm and 10mm in length were installed, respectively. Thus, the circumferential defect that was 5mm deep and 1mm wide created between the implant surface and the bony wall. Four implants placed in both sides of the mandible were allowed for non-submerged healing. Two dogs were sacrificed at the week 2,4 and 8 following implant placement, respectively, and the specimens were prepared and stained with trinitrophenol-fuchsin for histological and histomorphometric analyses to acquire the bone-to-implant contact（BIC%）, new bone fill （NBF%） and the distance between the most coronal level of bone-to-implant contact and the bottom of the surgically created bone defect （B-D）. Statistical analysis was conducted with SPSS13.0 software package. RESULTS： No implant was loosen or lost during the study. The histomorphometric results demonstrated that new bone formation was observed in the defect region around both groups of implants at all time points and the newly formed bone occurred initially from the apical and lateral bony wall of the defect region, the bone defect almost was filled at week 8. At 2 and 4 weeks of healing, the BIC%, NBF% and B-D values were significantly higher for modSLA implants （P0.05）. At 8 weeks of healing, the difference was not significant （P0.05）. CONCLUSIONS： The SLA implants processed by means of chemically-modified surface treatments exhibit more predictable outcomes than that of SLA implants by promoting the early bone regeneration when inserted into sites with bone defects. Supported by Research Fund of Shanghai Municipal Education Commission （Grant No.08zz57）, Key Research Project of Science and Technology Commission of Shanghai Municipality （Grant No.09411955000） and Nano-Science and Technology Project of Science and Technology Commission of Shanghai Municipality （Grant No.105znm04500）.