Electronic ohmmeter. An electronic device for the determination of the root canal length

The electronic ohmmeter was devised for the accurate determination of root canal length. Fifty-one maxillary anterior teeth of 43 patients and 25 posterior root canals from 10 patients were selected for the investigation. The presence of a lesion in periapical tissue, wide root apex, and exudates in the root canal contributed to inaccuracy in the determination of the root canal length. Correct length can be found if precautions are taken. The inaccurate results were corrected by repeating the procedures and taking precautions during the estimation of root canal length. Measurement in the dry canal gave correct estimation of the root canal length. When distilled water or normal saline was used as conducting medium in root canals, accuracy was not as good as in dry canals. The electronic ohmmeter is a useful and economical device and an endodontic aid for determination of the root canal length.