牙周炎主要是由特异性微生物的龈下感染所致，表现为牙周组织炎症和牙槽骨吸收。传统的牙周治疗是采用机械疗法清除局部刺激物。这种外科性质的清创术只能去除附着性菌斑，对于非附着性菌斑则未能奏效。四环素类药物近十多年来国内临床很少应用，近期国外学者认为盐酸四环素是? Periodontitis is caused mainly by subgingival infection of specific microorganisms, showing periodontal tissue inflammation and alveolar bone resorption. Traditional periodontal treatment uses mechanical therapy to remove local irritants. This surgical debridement only removes attached plaque and does not work for non-adhesive plaque. Tetracycline drugs rarely used in domestic clinical application of more than a decade, the recent foreign scholars believe that tetracycline hydrochloride is?