This study aimed to explore the period of endodontic treatment and the effects of periodontal-endodontic treatment for advanced periodontitis.A total of 180 patients with advanced periodontitis participated in this clinical multicenter study. The respondents were randomly divided into an endodontic combined treatment (experimental) group and a periodontal treatment alone (control) group; each group consisted of 90 teeth. The control group received periodontal therapy only. The experimental group received periodontal therapy and root-canal treatment, and then pulp status was recorded. The cases were followed up at 1, 3, 6, and 12 months after treatment.Out of 90 teeth in the test group, 22 teeth had completely necrotic pulps, 45 teeth had partial necrosis (coronal pulp necrosis or root pulp necrosis), and 23 had vital pulp. Differences between clinical parameters in the control and experimental groups were not significant (P0.05) before treatment but were significant after three months (P0.05).Pulp treatment for teeth with advanced periodontitis and dull pulp vitality can control the development of inflammation and thus benefit the healing of periodontal tissue.目的 探索重度牙周炎牙齿的牙髓治疗时机及牙周牙髓联合治疗对重度牙周炎的疗效。 方法 采用多中心研究方法,选择重度牙周炎患牙180颗,随机分为牙周牙髓联合治疗组(试验组)和单纯牙周治疗组(对照组),各90颗患牙。对照组仅进行牙周治疗;试验组记录牙髓状态,行根管治疗及牙周治疗;两组分别在治疗前和治疗后1、3、6及12个月进行检查,记录临床指标。 结果 试验组90颗患牙中,22颗牙髓完全坏死,45颗部分坏死(冠髓坏死或根髓部分坏死),23颗为活髓。治疗前,对照组和试验组各项临床指标的差异均无统计学意义(P0.05);治疗后3个月,试验组和对照组的临床指标开始出现差异(P0.05)。 结论 牙髓活力迟钝的重度牙周炎患牙及时进行完善的牙髓治疗,可控制炎症的发展,有利于牙周组织的愈合。.