Retreatment after recurrence still may achieve good effect.

复发再治疗依然可能有效。

Methods Endodontic retreatment with ultrasound was used in 156 cases.

方法应用156例牙髓治疗失败牙的再处理进行临床观察分析。

One-third of T790M neg PTS also respond, which cannot be explained by retreatment effect.

三分之一的T790M患者也能缓解，这不能通过再治疗作用进行解释。

Objective To investigate and evaluate the method of the endodontic retreatment therapy failure.

目的对牙髓治疗失败牙再处理和疗效作出评价。

There are many reasons for this retreatment, one of which includes the improper topic selection.

其原因是多方面的，其中一点便是在选题上存在问题。