牙外伤是口腔科的常见病之一，钢丝结扎固定外伤牙是临床上最常用的方法，本研究观察了钢丝结扎固定前、后的同一部位牙用组织及龈沟内产黑色素类杆菌群的变化情况。结果显示：牙龈指数及龈袋深度均有显著性差异（Ｐ＜０．０５）；与牙周组织病关系最为密切的致病菌──产黑色素类杆菌群的检出率明显提高，提示临床应对结扎患者进行正确的口腔卫生指导，从而进行特异性的预防。 Dental trauma is one of the common diseases in dentistry. Steel ligation and fixation of traumatic teeth are the most commonly used methods in clinic. In this study, the same part of dental tissues and gingival sulcular melanin-producing bacilli Changes. The results showed that there were significant differences in gingival index and gingival pocket depth (P <0.05). The most closely related pathogens in periodontal tissue disease - the detection rate of melanobacter group was significantly increased, suggesting that clinical Patients should be liaised for proper oral hygiene guidance to provide specific prevention.