Abstract
OBJECTIVES: This study aims to explore the mechanisms of the detrimental effects of postmenopausal osteoporosis (PMO) on periodontitis. METHODS: An ovariectomized (OVX) rat model was established to investigate the effects of PMO on alveolar bone homeostasis and periodontal inflammation. Chlorhexidine digluconate (CHX) was administered to rats with OVX - periodontitis to ascertain the involvement of the oral microbiota in the influence of PMO on periodontitis. Finally, oral microbiota transplantation was conducted to examine the oral microbiota's pathogenicity. RESULTS: OVX rats exhibited increased periodontal trabecular bone resorption and inflammation. In addition, depletion of the oral microbiota by CHX decreased the alveolar bone destruction in OVX - periodontitis rats. Furthermore, 16S rRNA gene sequencing demonstrated that PMO changes the composition of the oral microbiota. Finally, oral microbiota transplantation indicated that PMO enhanced the oral microbiota's pathogenicity. CONCLUSION: PMO detrimentally affects periodontitis by increasing periodontal inflammation and the pathogenicity of the oral microbiota, which provides a mechanistic understanding of how PMO affects periodontitis and highlights the necessity of more regular monitoring of the oral microbiota in PMO patients.