{"title":"Role of Actinomyces in the progression of medication-related osteonecrosis of the jaws in an immunocompromised mouse model with periapical disease","authors":"","doi":"10.1016/j.ajoms.2024.02.006","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><p>This study aimed to investigate the role of <em>Actinomyces</em> on the development of MRONJ in an immunocompromised mouse model with periapical disease.</p></div><div><h3>Methods</h3><p>Thirty ovariectomized C57BL/6 N female mice were treated with zoledronic acid (ZA) and dexamethasone (DX) for 12 weeks. At the eighth week of drug administration, pulpal exposure operation was performed on the lower right first molar in Group B and C, meanwhile <em>Actinomyces</em> inoculation was performed at the pulpal entrance of Group C. Group A received no operation as control. After 4 weeks, loads of total bacteria and <em>Actinomyces</em> in the oral cavity were assessed by real-time polymerase chain reaction (PCR). Mandibles were harvested for micro-computed tomography (CT) and histological analysis.</p></div><div><h3>Results</h3><p>Real-time PCR revealed positive detection of <em>Actinomyces</em> in 30% samples in Group C and negative detection in all samples in Group B and control group. Micro-CT examination demonstrated that in ZA treated mice, pulpal exposure significantly increased periapical bone loss, which was significantly aggravated by <em>Actinomyces</em> inoculation. Histological assessment showed vasodilation, acute exudative changes and pulp necrosis in Group B and C.</p></div><div><h3>Conclusions</h3><p>The present study revealed that inoculation of <em>Actinomyces</em> compromises the bone quality but does not further aggravate bone necrosis significantly.</p></div>","PeriodicalId":45034,"journal":{"name":"Journal of Oral and Maxillofacial Surgery Medicine and Pathology","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Oral and Maxillofacial Surgery Medicine and Pathology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2212555824000176","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"DENTISTRY, ORAL SURGERY & MEDICINE","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives
This study aimed to investigate the role of Actinomyces on the development of MRONJ in an immunocompromised mouse model with periapical disease.
Methods
Thirty ovariectomized C57BL/6 N female mice were treated with zoledronic acid (ZA) and dexamethasone (DX) for 12 weeks. At the eighth week of drug administration, pulpal exposure operation was performed on the lower right first molar in Group B and C, meanwhile Actinomyces inoculation was performed at the pulpal entrance of Group C. Group A received no operation as control. After 4 weeks, loads of total bacteria and Actinomyces in the oral cavity were assessed by real-time polymerase chain reaction (PCR). Mandibles were harvested for micro-computed tomography (CT) and histological analysis.
Results
Real-time PCR revealed positive detection of Actinomyces in 30% samples in Group C and negative detection in all samples in Group B and control group. Micro-CT examination demonstrated that in ZA treated mice, pulpal exposure significantly increased periapical bone loss, which was significantly aggravated by Actinomyces inoculation. Histological assessment showed vasodilation, acute exudative changes and pulp necrosis in Group B and C.
Conclusions
The present study revealed that inoculation of Actinomyces compromises the bone quality but does not further aggravate bone necrosis significantly.
方法30只卵巢切除的C57BL/6 N雌性小鼠接受唑来膦酸(ZA)和地塞米松(DX)治疗12周。给药第八周时,在 B 组和 C 组的右下第一磨牙上进行牙髓暴露手术,同时在 C 组的牙髓入口处接种放线菌。4 周后,通过实时聚合酶链反应(PCR)评估口腔中的细菌总数和放线菌数量。结果实时聚合酶链反应显示,C 组 30% 的样本中放线菌检测呈阳性,而 B 组和对照组所有样本中放线菌检测呈阴性。显微 CT 检查显示,ZA 治疗小鼠的牙髓暴露明显增加了根尖周骨质流失,而放线菌接种则明显加剧了这种流失。组织学评估显示,B 组和 C 组出现血管扩张、急性渗出性变化和牙髓坏死。