Abstract
Aims: the aim of this in vitro study was to evaluate the apical sealing ability where the canals are pre-paid by two rotary NiTi systems . Materials and Methods: Thirty-six extracted human teeth with sin-gle root cut there crowns at the cemento-enamel junction CEG. The working length was determined for each tooth. The teeth were divided in to (3)groups ten of each . Group I the teeth were instrumented with ProTaper NiTi then the teeth obturated with matched-taper single cone. Group II of teeth were instrumented with RaCe NiTi rotary instrument and then obturated with matched-taper single cone. Group III were instrumented by hand instruments K-files and obturated by the lateral condensation techniques. Six teeth were divided as positive and negative control group three for each one . Tgadeseal was used as root canal sealer in this study. Adye penetration method was used to evaluate the apical seal using steromicroscope at 40X magnification. One-way analysis of variance and Duncan's test were used for statistical analysis. Results: The statistical analysis of the results demonstrated that there was no statistically significant difference in Microleakge between the two different rotary instrument each ProTaper and RaCe. While there was significant difference between the rotary instrument and the Hand instrument K-files. Conclusions: The use of the NiTi rotary instrument for root canal preparation showed the least apical microleakage, in compaired with hand instrument
