INTRODUCTION: The purpose of this in vitro evaluation was to study the accuracy of Root ZX and ProPex system during retreatment of canals obturated with different obturating materials (gutta-percha + zinc oxide-eugenol sealer, gutta-percha + AH plus sealer, and Resilon + Epiphany sealer). METHODS: Sixty human mandibular premolar roots were instrumented with Rotary ProTaper until size F4 under copious irrigation. After instrumentation, actual working length was directly measured by using #15 FlexoFile. Electronic working length was taken with the help of Root ZX and ProPex. Teeth were divided into 3 groups and obturated by using lateral condensation of gutta-percha + zinc oxide-eugenol sealer (group I), gutta-percha + AH plus sealer (group II), and Resilon + Epiphany sealer (group III). After 7 days, the obturating materials were removed by using Gates-Glidden burs and K-files. A new electronic working length was taken. Original and post-treatment electronic working lengths were compared with actual working length. Accuracy of both electronic root canal length measurement devices was calculated for tolerance limits of +/-0.5 mm and +/-1.0 mm. Accuracy was compared by using chi(2) tests, and difference between actual working length and original and post-treatment electronic working lengths was compared by using Student t test. RESULTS: The accuracy of electronic root canal length measurement devices before root canal obturation was 83.3% and 93.3% for Root ZX and ProPex, respectively, for a tolerance limit of +/-0.5 mm and 100% for a tolerance limit of +/-1.0 mm. There was no statistically significant effect of different obturating materials tested in this study on the accuracy of Root ZX and ProPex for tolerance limits of +/-0.5 mm and +/-1.0 mm. Student t test revealed insignificant differences between the mean of actual working length and original and post-treatment electronic working lengths. CONCLUSIONS: Root ZX and ProPex can be a useful adjunct with a high accuracy rate during root canal preparation and retreatment. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
INTRODUCTION: The purpose of this in vitro evaluation was to study the accuracy of Root ZX and ProPex system during retreatment of canals obturated with different obturating materials (gutta-percha + zinc oxide-eugenol sealer, gutta-percha + AH plus sealer, and Resilon + Epiphany sealer). METHODS: Sixty human mandibular premolar roots were instrumented with Rotary ProTaper until size F4 under copious irrigation. After instrumentation, actual working length was directly measured by using #15 FlexoFile. Electronic working length was taken with the help of Root ZX and ProPex. Teeth were divided into 3 groups and obturated by using lateral condensation of gutta-percha + zinc oxide-eugenol sealer (group I), gutta-percha + AH plus sealer (group II), and Resilon + Epiphany sealer (group III). After 7 days, the obturating materials were removed by using Gates-Glidden burs and K-files. A new electronic working length was taken. Original and post-treatment electronic working lengths were compared with actual working length. Accuracy of both electronic root canal length measurement devices was calculated for tolerance limits of +/-0.5 mm and +/-1.0 mm. Accuracy was compared by using chi(2) tests, and difference between actual working length and original and post-treatment electronic working lengths was compared by using Student t test. RESULTS: The accuracy of electronic root canal length measurement devices before root canal obturation was 83.3% and 93.3% for Root ZX and ProPex, respectively, for a tolerance limit of +/-0.5 mm and 100% for a tolerance limit of +/-1.0 mm. There was no statistically significant effect of different obturating materials tested in this study on the accuracy of Root ZX and ProPex for tolerance limits of +/-0.5 mm and +/-1.0 mm. Student t test revealed insignificant differences between the mean of actual working length and original and post-treatment electronic working lengths. CONCLUSIONS: Root ZX and ProPex can be a useful adjunct with a high accuracy rate during root canal preparation and retreatment. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.