Efficacy of two rotary NiTi instruments in the removal of Gutta-Percha during root canal retreatment.

The aim of this study was to evaluate the efficacy of ProTaper and K3 in the removal of gutta-percha during root canal retreatment in comparison with hand Hedstrom files. Time of gutta-percha removal and amount of apically extruded debris were also evaluated. Sixty extracted single-rooted anterior teeth and premolars were instrumented and obturated with laterally condensed gutta-percha technique. The teeth were cleared and randomly divided into three groups of 20 teeth each. The roots were split longitudinally, digital images were created using a scanner, and the areas of remaining filling material were traced using Ulead Photoimpact7 then calculated using SigmaScan software. The results indicated that the two rotary nickel-titanium instruments left significantly less remaining filling material than hand instruments (p < 0.001). The ProTaper and K3 required significantly less time for filling material removal than hand instruments (p < 0.001). There was no statistically significant difference among the three techniques regarding the amount of apically extruded debris (p = 0.159). In conclusion, ProTaper and K3 were found to be effective and faster in removing gutta-percha.

Efficacy of a new brush-covered irrigation needle in removing root canal debris: a scanning electron microscopic study.

The usefulness of NaviTip FX, a brush-covered irrigation needle, in endodontic therapy has never been reported. Therefore, the purpose of this investigation was to evaluate the cleaning efficacy of this new brush-covered irrigation needle, the NaviTip FX. Thirty single-rooted teeth were randomly divided into two equal groups and instrumented using the crown-down technique with 0.04 taper ProFile. Following each file use, the canals were irrigated with 1 ml of 5.25% NaOCl using the NaviTip FX needle for group 1 or using the same needle without the brush for group 2. At the end of instrumentation, the roots were cut longitudinally and each half was divided into three equal parts. The specimens were then routinely prepared for scanning electron microscopic evaluation. The results showed that using the NaviTip FX produced cleaner coronal thirds of instrumented root canals compared to the control group. On the other hand, the middle and apical thirds were not statistically significantly different between the two groups. Further development of this irrigation technique to improve cleanliness of the apical and middle thirds is required before the NaviTip FX can be recommended for routine use during root canal therapy.