Department of Prosthodontics, Saarland University, Homburg, Germany.
Institute for Clinical and Experimental Surgery, Saarland University, Homburg, Germany.
Clin Exp Dent Res. 2021 Aug;7(4):490-501. doi: 10.1002/cre2.390. Epub 2021 Jan 4.
The preclinical evaluation of bone substitutes is frequently performed in artificially created defects. However, such defects do not reflect the predominant clinical application of bone substitutes for socket preservation. Hence, the goal of this animal study was to compare the performance of a xenogenic bone substitute in extraction sites versus artificial defects.
Four study sites each were created in the mandibles of four minipigs in the region of the third premolars and first molars, respectively. On one side, fresh extraction sockets were established while contralaterally trephine defects were created in healed alveolar bone. All sites were augmented using a particulate xenogenic bone substitute, covered by resorbable membranes and allowed to heal for 12 weeks. The amounts of new bone, non-bone tissue and remaining bone substitute granules were quantified through histological and micro-CT analysis. Comparative statistics were based on t-tests for two samples and ANOVA with the level of significance set at α = 0.05.
Histomorphometric data from only two animals could be quantitatively analyzed due to difficulty with identifying the surgical sites. The percentage of newly formed bone ranged between 53.2% ± 5.6% for artificial defects and 54.9% ± 12.4% for extraction sites. With the exception of ANOVA indicating a greater amount of non-bone tissue in extraction sites as compared to artificial sites (p = 0.047), no statistically significant differences were observed. Micro-CT scans showed patterns similar to the ones observed in histomorphometry. As extraction sites could be identified only in two micro-CT reconstructions, quantitative assessment was not undertaken.
Despite the comparable performance of bone substitute material in artificial defects and extraction sites found here, the data gathered with this experiment was insufficient for showing equivalence of both approaches.
骨替代物的临床前评估通常在人为创建的缺陷中进行。然而，这些缺陷并不能反映骨替代物在牙槽窝保存中的主要临床应用。因此，本动物研究的目的是比较异种骨替代物在拔牙窝与人工缺陷中的性能。
在四只小型猪的下颌第三前磨牙和第一磨牙区域，分别在四个研究部位创建一个部位。一侧建立新鲜拔牙窝，而对侧在愈合牙槽骨中制备钻取缺陷。所有部位均使用颗粒状异种骨替代物进行增强，并用可吸收膜覆盖，并允许愈合 12 周。通过组织学和微 CT 分析，对新骨、非骨组织和剩余骨替代颗粒的量进行量化。基于两个样本的 t 检验和方差分析的比较统计，显著性水平设为 α = 0.05。
由于难以识别手术部位，只有两只动物的组织形态计量学数据可以进行定量分析。人工缺陷的新骨形成百分比在 53.2%±5.6%之间，拔牙窝的新骨形成百分比在 54.9%±12.4%之间。除了方差分析表明拔牙窝的非骨组织量大于人工缺陷（p = 0.047）外，没有观察到统计学上的显著差异。微 CT 扫描显示的模式与组织形态计量学观察到的模式相似。由于仅在两个微 CT 重建中可以识别拔牙窝，因此未进行定量评估。
尽管在这里发现骨替代物在人工缺陷和拔牙窝中的性能相当，但本实验获得的数据不足以证明两种方法的等效性。
