Comparative study on the rate of corespondent of working length determined by three methods

AIM: To evaluate the rate of coresppondent of working length determined by three methods.METHODS: Patents with 153 teeth with 358 root canals needing root canal therapy were selected clinically.TIR AUTO ZX root canal apex locator was applied for the determination of the working length.The working length measured with root canal apex locator was compared with X-ray photogrammetry and defction method using dental instrument.RESULTS: The rate of corespondent of working length determined by TRI AUTO ZX root canal apex locator was 92.46% compared with X-ray photogrammetry,67.88% compared with detection mcthod using dental instrument,and the rate of corespondent of working length determination by X-ray photogrammetry is 64.53% compared with detection method using dental instrument.CONCLUSION: The method of root canal length measured with TRI AUTO ZX root canal apex locator is one kind of accurate and impersonal one.