An in vitro evaluation of performance of two electronic root canal length measurement devices during retreatment of different obturating materials.
BACKGROUND
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.
Aggarwal
Vivek
V
Department of Dental Surgery, Safdarjung Hospital, New Delhi, India. drvivekaggarwal@gmail.com
Singla
Mamta
M
Kabi
Debipada
D
D001641:Bicuspid / Q000033:anatomy & histology / Q000601:surgery; D016009:Chi-Square Distribution; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000601:surgery; D017097:Electric Impedance; D004853:Epoxy Resins / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008334:Mandible; D009811:Odontometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D019227:Tooth Apex / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology* / Q000601:surgery; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer; C486892:resilon sealer; D006171:Gutta-Percha