Heinonen Venni, Ruotsalainen Timo J, Paavola Lauri, Mikkonen Jopi J, Asikainen Pekka, Koistinen Arto P, Kullaa Arja M
a Department of Oral Diagnostic Sciences, Institute of Dentistry , University of Eastern Finland , Kuopio , Finland.
b Dental Education clinic , Kuopio , Finland.
Ultrastruct Pathol. 2018 Mar-Apr;42(2):124-132. doi: 10.1080/01913123.2017.1422829. Epub 2018 Feb 9.
The aim of the present study is to investigate the morphological and cellular changes in dental extraction socket that has been irradiated after the tooth extraction and to describe morphological characteristics of the osteocytes and osteocyte-lacunar-canalicular network (LCN) by scanning electron microscopy (SEM).
Five beagle dogs aged 1-2 years were used in this study. One side of each mandible was irradiated in two sessions and the other side of mandible (non-irradiated) served as a control. The mandible bone blocks were processed by bulk staining en bloc in basic fuchsin and the specimens were embedded routinely in polymethyl methacrylate resin without preliminary decalcification. All blocks were subjected to micro-CT imaging, after that the specimens were prepared for light microscopy and SEM.
Alterations in bone macrostructure are minimal in irradiated bone, but the changes in LCN are clear. In the area of the tooth extraction socket, the connections of osteocytes to the vessels and to neighboring osteocytes were not observed both in irradiated and nonirradiated bone. However, osteoclasts were located in the bone surface entering inside to the bone between osteons. In the lamellar bone of lateral sides, a decrease in canalicular connections between osteocytes and periosteum was found in irradiated bone as compared to the non-irradiated side.
The novelty of the present study is that radiation disrupts osteocytes and their dendrites.
本研究旨在调查拔牙后接受照射的拔牙窝的形态学和细胞变化，并通过扫描电子显微镜（SEM）描述骨细胞和骨细胞-陷窝-小管网络（LCN）的形态学特征。
本研究使用了5只1-2岁的比格犬。每只下颌骨的一侧分两次进行照射，下颌骨的另一侧（未照射）作为对照。下颌骨骨块采用碱性品红整体染色处理，标本常规包埋于聚甲基丙烯酸甲酯树脂中，无需预先脱钙。所有骨块均进行显微CT成像，之后制备用于光学显微镜和扫描电子显微镜观察的标本。
照射骨的骨宏观结构改变最小，但LCN的变化明显。在拔牙窝区域，照射骨和未照射骨中均未观察到骨细胞与血管及相邻骨细胞之间的连接。然而，破骨细胞位于骨表面，进入骨单位之间的骨内。在外侧的板层骨中，与未照射侧相比，照射骨中骨细胞与骨膜之间的小管连接减少。
本研究的新颖之处在于辐射会破坏骨细胞及其树突。
