Ferreira Beatriz Carmona, Freire Alexandre Rodrigues, Araujo Rafael, do Amaral-Silva Gleyson Kleber, Okamoto Roberta, Prado Felippe Bevilacqua, Rossi Ana Cláudia
Laboratory for Mechanobiology Research, Biosciences Department, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
São Leopoldo Research Institute, São Leopoldo Mandic University, Campinas, Brazil.
Front Physiol. 2020 Jun 5;11:549. doi: 10.3389/fphys.2020.00549. eCollection 2020.
The aim of this study was to analyze the relationship between alveolar bone deformation and β-catenin expression levels in response to the mechanical load changed by dental extraction in adult rats. Twenty-four male rats (), Wistar linage, at 2 months of age, were used. The right upper incisor tooth was extracted, and euthanasia occurred in periods 5 ( = 6), 7 ( = 6), and 14 ( = 6) days after Day 0. In the control group ( = 6), the dentition was maintained. The euthanasia occurred within 14 days after day 0. After euthanasia, the rats of all groups had their left jaw with tooth removed and separated in the middle. The pieces were undergone routine histological processing and then the immunohistochemical marking were performed to label expression of the primary β-catenin antibody, which was evaluated by qualitative and quantitative analysis. One head by each group (control and experimental) was submitted to computerized microtomography. After the three-dimensional reconstruction of the skull of the rat in each group, the computational simulation for finite elements analysis were performed to simulate a bite in the incisors. In finite element analysis, the strain patterns were evaluated after the application of bite force. The results were analyzed considering the areas in which changes in the amount of deformations were detected. The action of the bite force in the experimental condition, resulted in a uniform distribution of the amount of deformations, in addition to lower amount of deformation areas, differentiating from the control group. Comparing with the control group, the levels of β-catenin signaled in the lingual bone of the middle third of the alveolar bone were raised in the periods of 5 and 14 days. The increased β-catenin positive staining intensity was concentrated on osteocytes and gaps of osteocytes. The findings of the present study were in accordance with our hypothesis that the condition of dental extraction can cause the expression of β-catenin and alter the regimes of bone deformation.
本研究的目的是分析成年大鼠拔牙后机械负荷变化时牙槽骨变形与β-连环蛋白表达水平之间的关系。选用24只2月龄的雄性Wistar系大鼠。拔除右上切牙，并在第0天之后的第5天（n = 6）、第7天（n = 6）和第14天（n = 6）实施安乐死。对照组（n = 6）保留牙列，在第0天之后的14天内实施安乐死。安乐死后，所有组的大鼠均取下左侧带牙颌骨并从中部切开。切片进行常规组织学处理，然后进行免疫组织化学标记以标记主要β-连环蛋白抗体的表达，并通过定性和定量分析进行评估。每组（对照组和实验组）各取一个样本进行计算机显微断层扫描。对每组大鼠的颅骨进行三维重建后，进行有限元分析的计算模拟以模拟切牙咬合。在有限元分析中，施加咬合力后评估应变模式。根据检测到变形量变化的区域分析结果。与对照组相比，实验条件下咬合力的作用导致变形量均匀分布，变形区域数量减少。与对照组相比，牙槽骨中三分之一舌侧骨中β-连环蛋白的信号水平在第5天和第14天升高。β-连环蛋白阳性染色强度增加集中在骨细胞和骨细胞间隙。本研究结果符合我们的假设，即拔牙情况可导致β-连环蛋白表达并改变骨变形状态。
