牙髓根尖周病根管治疗疗效预测模型的建立

目的：初步建立牙髓根尖周病根管治疗后2年临床疗效预测模型。方法：基于根管治疗后2年疗效临床回顾性研究，以因牙髓根尖周病接受根管治疗及术后2年随访的360例患牙为研究样本，随机抽取约67%为训练样本（建立模型），其余为验证样本（模型外部验证）。以影像学评价结果为疗效标准，应用Logistic回归方法以根尖周有/无病变、根尖周病变是/否缩小为因变量分别建立临床疗效预测模型。以受试者工作特征（receiver opera-ting characteristic，ROC）曲线下面积（area under curve，AUC）评价模型预测能力。结果：以根尖周有/无病变为因变量建立模型一，纳入术前根尖周有无病变、根管弯曲度、根管充填长度及密度建模，模型AUC为0.802（95%CI: 0.744~0.859），验证样本检验外部效度结果为0.688。以根尖周病变是否缩小为因变量建立模型二，根管充填长度和密度参与建模，模型AUC为0.734（95%CI: 0.612~0.856），外部验证结果为0.681。根管重度弯曲、根管治疗质量好的牙髓炎患牙接受根管治疗术后2年，通过模型一预测，根尖周无病变概率达90%，慢性根尖周炎患牙病变愈合概率为51%。应用模型二预测，慢性根尖周炎患牙根管治疗后2年，根管充填质量好的病例出现病变缩小的概率为95%，而根管充填质量不佳者病变缩小的概率仅为39%。结论：术前根尖周状态、根管弯曲情况、根管治疗质量可用于预测根管治疗后2年临床疗效。

A prognostic model for assessment of outcome of root canal treatment in teeth with pulpitis or apical periodontitis

Objective: To present a prognostic model for evaluating the outcome of root canal treatment in teeth with pulpitis or apical periodontitis 2 years after treatment. Methods: The implementation of this study was based on a retrospective study on the 2-year outcome of root canal treatment. A cohort of 360 teeth, which received treatment and review, were chosen to build up the total sample size. In the study, 143 teeth with vital pulp and 217 teeth with apical periodontitis were included. About 67％ of the samples were selected randomly to derive a training date set for modeling,and the others were used as validating date set for testing. Logistic regression models were used to produce the prognostic models. The dependent variable was defined as absence of periapical lesion or reduction of periapical lesion. The predictability of the models was evaluated by the area under the receiver-operating characteristic (ROC ) curve (AUC). Results: Four predictors were included in model one (absence of apical lesion): preoperative periapical radiolucency,canal curvature,density and apical extent of root fillings. The AUC was 0. 802 (95％ CI: 0. 744-0. 859). And the AUC of the testing date was 0. 688. Only the density and apical extent of root fillings were included to present model two (reduction of apical lesion). The AUC of training dates and testing dates were 0. 734 (95％ CI: 0. 612-0. 856) and 0. 681,respectively. As predicted by model one,the probability of absence of periapical lesion 2 years after endodontic treatment was 90％ in pulpitis teeth with sever root-canal curvature and adequate root canal fillings, but 51％ in teeth with apical periodontitis. When using prognostic model two for prediction, in teeth with apical periodontitis, the probability of detecting lesion reduction with adequate or inadequate root fillings was 95％ and 39％ 2 years after treatment. Conclusion: The pre-operative periapical status, canal curvature and quality of root canal treatment could be used to predict the 2-year outcome of root canal treatment.