1.Department of Oral Implantology,Affiliated Hospital of Stomatology,Nanjing Medical University;2.Jiangsu Key Laboratory of Oral Diseases,Nanjing Medical University,Nanjing 210029;3.China
目的 构建新西兰兔上颌前牙即刻种植的实验动物模型，观察不同时间点的种植体骨结合特征。方法 准备16只新西兔，随机分为2w、4w、8w、12w组，每组4只。拔除兔的上颌前牙，在其新鲜拔牙窝内即刻植入纯钛实验种植体。术后分别在2w、4w、8w、12w采集含种植体的上颌骨标本，再通过大体观察、Micro-CT扫描、组织切片染色研究即刻种植后不同时间点的种植体骨结合特征。结果 ① 大体观察：各组实验兔的术后状态正常，食欲无明显异常，创口愈合良好，种植体均未松动脱落。② Micro-CT分析：随着种植体植入后愈合时间的延长，种植体螺纹处的骨质密度和厚度不断增加。③ 组织学检测：随着种植体植入后时间的延长，硬组织切片染色测算所得的种植体-骨接触率(bone-implant contact ratio, BIC)稳步增长，而脱钙颌骨切片染色显示种植体周围的骨质结构呈散在-岛状-条索状-板层状骨演化，提示骨结合形成良好。2w和4w组中存在大量的破骨细胞和炎症细胞，8w和12w组中则几乎未见这类细胞，但存在更多的红细胞和黄骨髓。结论 兔上颌前牙拔除后即刻植入种植体可构建即刻种植动物模型，为即刻种植后骨结合过程的观察以及钛种植体的动物体内研究提供新的选择和途径。
Objective To establish an animal model of immediate implantation for maxillary anterior teeth of New Zealand rabbits and observe its osseointegration at different time points. Methods A total of 16 New Zealand rabbits were randomly divided into 4 groups according to 2w, 4w, 8w and 12w, with 4 rabbits in each group. After surgery, maxillary specimens containing implants were collected at 2w, 4w, 8w and 12w respectively. The characteristics of implant osseointegration at different time points after immediate implantation were studied by observation, Micro-CT scanning and tissue section staining. The maxillary anterior teeth of rabbits were extracted and pure titanium experimental implants were immediately implanted in the fresh extraction sockets. Maxillary specimens containing implants were collected at 2, 4, 8 and 12 weeks postoperatively, and the characteristics of implant osseointegration at different time points after immediate implantation were studied by general observation, Micro-CT scanning, and staining of tissue sections. Results (1) General observation: The rabbits in each group had normal postoperative state, no obvious abnormality of appetite, good wound healing, and no loosening or falling off implants. (2) Micro-CT analysis: The bone density and thickness at the thread of implant increased continuously with the extension of healing time after implantation. (3) Histological examination: According to the time after implantation, the bone-implant contact ratio (BIC) measured by staining of hard tissue sections increased steadily, and the bone structure around the implant, as shown in the staining of decalcified jaw sections, exhibited the evolution of scattered-island-cord-lamellar bone, indicating the formation of osseointegration. Many osteoclasts and inflammatory cells were observed in 2w and 4w groups, whereas almost no such cells in 8w and 12w groups, which had more red blood cells and yellow bone marrow. Conclusions Performing implantation immediately after extraction of maxillary anterior teeth in rabbits can establish an animal model of immediate implantation, which provides a new way for observation of the osseointegration process after immediate implantation and in vivo study of titanium implants.