Working length determination in general dental practice: a randomised controlled trial

Objective To evaluate the ability of apex locators as a tool in determining working length in comparison to traditional working length radiographs in general dental practice. Design Randomised controlled clinical trial. Setting General dental practices in the North West of England. Subjects Adults requiring root canal treatment of at least one tooth with minimal or moderate difficulty. Intervention Root canal treatment was carried out with the working length determined by apex locator in the treatment group (AL), and periapical radiograph in the control group (PA). Outcome measure The acceptability of the master cone gutta percha measured from a radiograph before obturation was used as the primary outcome. Results Twenty-one of 23 fillings in the AL group were judged as acceptable, compared to 17 of 23 fillings in the PA group. This difference was not statistically significant. Conclusion In general dental practice, no significant difference was found in working length determined using apex locator combined with a master cone GP radiograph or using the conventional method. There is a need for larger trials to investigate these methods further.