RESUMO
INTRODUCTION: This study was conducted in vivo to investigate the accuracy of Root ZX II in locating the apical foramen in teeth with apical periodontitis (AP). METHODS: Twenty-seven single-root teeth scheduled for extractions were selected; in AP group, there were 12 teeth with pulp necrosis and radiographic evidence of apical lesions, and VT group consisted of 15 vital teeth. After endodontic access, the coronal portion of the canal was flared, and electronic measurement was performed by using a 15 K-file until the device level reading "APEX" was reached. The file was fixed in place, and the tooth was extracted. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained. RESULTS: The mean distance in AP group was +0.117 (standard deviation, 0.373) and in VT group was -0.105 (standard deviation, 0.218). The unpaired t test showed no difference between the groups when comparing the mean distances (P > .05). The apical foramen was accurately located within ±0.5 mm in 83% of the teeth in AP group and in 100% of VT group. Statistical analysis showed no difference between the groups (P = .1092). CONCLUSIONS: The Root ZX II device was accurate in locating the apical foramen regardless of the presence of AP.