The influence of diameters of root canal foramen on the accuracy of Root ZX and Neosono Ultima EZ

Objective:To investigate the effect of diameter of root canal foramen on the accuracy of two apex locators.Method:Use the agar model and glass capillaries to mimic root canals in vivo.Record the distance between measured length and the real length of the capillaries as the IF value by using a No.15 stainless steel K file,Root ZX and Neosono Ultima EZ under two measuring environments(dry and 2.5%NaClO).All the data were subject to correlation analysis.Result:The IF values of Root ZX had no relation to the diameters of capillaries when the capillaries were dry,but had positive proportion to the diameters of capillaries(r0,P0.05) with the capillaries full of 2.5%NaClO solution.The IF values of Neosono Ultima EZ had no relation to the diameters of capillaries under both measuring enviroments.Conclusion:The accuracy of Root ZX is reverse to the diameter of root canal foramen with electrolytes in the root canal.The accuracy of Neosono Ultima EZ is not impacted by the diameter of root canal foramen under various measuring enviroments.