Occurrence of no-function of two electronic apex locators: an in vivo study.

ABSTRACT

OBJECTIVES: This in vivo study was aimed at quantifying the electronic no-function rate of 2 electronic apex locators, ApexPointer and Novapex, and evaluating whether their operation is affected by the type of applied treatment, patient's age, and the type of tooth. STUDY DESIGN: A total of 209 root canals were included in this study. For each canal, the electronic length was determined and verified by radiography. Whenever the electronic device failed to provide a value, it was recorded as an electronic no-function. Experimental data were statistically tested with chi-squared through Statview. RESULTS: For both apex locators, the no-function rate remained around 15% and did not seem to be affected by the age of patients. A statistically significant relationship was found between no-function rate and retreatment (P < .05). The type of tooth had no influence on the no-function rate. CONCLUSIONS: Under the conditions of this assessment in vivo, the 2 apex locators proved to give no value in about 15% of the cases. Further investigations are necessary to clear up the links between no-function and retreatment or age.