Ruehe Baerbel, Heberer Susanne, Bayreuther Katja, Nelson Katja
Department of Oral and Maxillofacial Surgery, Charité Campus Virchow, Free and Humboldt University of Berlin, Berlin, Germany.
J Oral Implantol. 2011;37(1):3-17. doi: 10.1563/AAID-JOI-D-09-00090. Epub 2010 Jun 17.
Spontaneous early exposure of submerged implants during the healing phase as a factor for early crestal bone loss around the implants is still being controversially discussed. The aim of this study was to examine the potential impact of dehiscences on the osseointegration process of acid-etched dental implants with a shortened healing period in the maxilla. Five animals received a total of 15 titanium implants 8 weeks postextraction. Eight of these implants were placed in the maxilla to osseointegrate within a shortened healing period of 3 months, whereas the remaining implants were inserted in the lower jaw and served as controls with a regular healing time. Polyfluorochrome sequential labeling with xylenol orange, calcein green, and alizarin complexone was performed 2, 5, and 8 weeks after implant placement. After 12 weeks of unloaded and submerged healing, the animals were killed and the implants removed en bloc. After the processing of the undecalcified PMMA-embedded samples, thin ground sections (40-60 µm) were made. The histomorphometric determination of the bone-to-implant contact (BIC) was calculated using light microscopy. The peri-implant bone apposition rate and the direction of bone growth were determined with the fluorescence microscope. For statistical evaluation, the Mann-Whitney U test, Wilcoxon signed ranks test, and Friedman test were chosen. During the healing period, nonartificial dehiscences were observed at 9 implants. The average BIC was 54.19% (14.51%-68.97%). There were significantly lower BIC rates detected for the cervical part of the implants compared with the middle part. An influence of dehiscences on the osseointegration could not be proven. There were no significant differences between the BIC values of the upper and lower jaw. During the observation period from the third to the eighth week after implantation, the average new bone formation rate was 2.32 µm/d (1.76-2.82 µm/d). During this period, the amount of new bone growth decreased insignificantly. Based on the sequence of the polyfluorochrome labeling, an implantopetal (53.03%) as well as an implantofugal bone growth (46.97%) have been observed. It could be assumed that the acid-etched implants offered a prerequisite to osseointegrate under a shortened healing period. The observed dehiscences seemed not to have compromised the rate of osseointegration.
在愈合阶段，种植体早期自发暴露作为种植体周围早期牙槽嵴骨吸收的一个因素，目前仍存在争议。本研究的目的是探讨上颌骨中愈合期缩短的酸蚀牙种植体骨结合过程中骨开裂的潜在影响。5只动物在拔牙后8周共植入15枚钛种植体。其中8枚种植体植入上颌骨，在3个月的缩短愈合期内实现骨结合，其余种植体植入下颌骨作为对照，愈合时间正常。在种植体植入后2周、5周和8周进行了用二甲酚橙、钙黄绿素和茜素络合酮的多荧光色素序列标记。在无负载和浸没愈合12周后，处死动物并将种植体整体取出。对未脱钙的PMMA包埋样本进行处理后，制作了40 - 60μm的薄磨片。使用光学显微镜计算骨与种植体接触（BIC）的组织形态计量学指标。用荧光显微镜确定种植体周围骨沉积率和骨生长方向。为进行统计学评估，选择了曼 - 惠特尼U检验、威尔科克森符号秩检验和弗里德曼检验。在愈合期，9枚种植体出现了非人为的骨开裂。平均BIC为54.19%（14.51% - 68.97%）。与种植体中部相比，种植体颈部的BIC率显著更低。未证实骨开裂对骨结合有影响。上颌骨和下颌骨的BIC值之间无显著差异。在植入后第三至第八周的观察期内，平均新骨形成率为2.32μm/d（1.76 - 2.82μm/d）。在此期间，新骨生长量的减少不显著。根据多荧光色素标记的顺序，观察到了向心性骨生长（53.03%）以及离心性骨生长（46.97%）。可以认为，酸蚀种植体为在缩短的愈合期内实现骨结合提供了前提条件。观察到的骨开裂似乎并未影响骨结合率。
