Assessment of root canal enlargement using Mtwo and BioRace rotary files

Maintenance Evaluation of the Original Anatomy of the Root Canal Diameters Instrumented with Mtwo and BioRace Systems

Objective:The aim of the present study was to evaluate maintenance of the original anatomy of the root canal diameters instrumented with the Mtwo rotary instruments and BioRace file systems. Material and method:Acrylic resin blocks with 160 simulated root canals with an angle curvature 15°-30° were taken into consideration in the present comparative study. The 160 simulated root canals were divided into two groups, each of them containing 80 acrylic resin blocks. Each group was divided into two subgroups (n=40 canals each). The simulated root canals subgroups were prepared with Mtwo and BioRace rotary nickel-titanium instruments. The results were scrutinized using analysis of variance (ANOVA)-test and Tukey's test. The significance level was set at P < 0.05. Results:No significant difference was noted between the Mtwo rotary instruments and BioRace files as they both had equal value in the coronal section (P=.000) in S1 (D1) and S1 (Dpi). The results of Tukey's test revealed a significant difference between the Mtwo rotary instruments and BioRace files in middle and apical section with the value (P=.003) in S3 (Dpi) and S4 (Dpi). The results of Tukey's test found out a significant difference between the Mtwo rotary instruments and BioRace files in the middle and apical section with the respective values (P=.003) in S3 (Ai) and (P=.006) in S4 (Ai). Conclusion:Ccording to the findings of the present study, enlargement of the root canal diameters resulted to be better on the middle and apical section of the canal prepared with Mtwo instruments in comparison with BioRace instruments. Thus, Mtwo instruments will increase the rate of success of endodontic therapy.

Canal Straightening Following Overinstrumentation with Three Nickel-Titanium Rotary Instruments

AIM

The aim of the present in vitro study to compare canal straightening following shaping of curved canals with three types of new generation nickel-titanium (NiTi) rotary instruments-ProTaper Next (PTN)®, BT RaCe (BTR)®, and WaveOne Gold (WOG)®- and three different levels of protrusion beyond the major apical foramen.

MATERIALS AND METHODS

Forty-five extracted human maxillary and mandibular molars with at least one curved canal were distributed in three comparable groups of 15 canals each. The canals were instrumented to the major foramen and then overinstrumented with the final file 0.5 mm, 1 mm, and 1.5 mm beyond the foramen using PTN (Group PTN = 15), BTR (Group BTR = 15), and WOG (Group WOG = 15). Standardized pre- and post-instrumentation radiographs of the root canal were obtained for all groups using digital intraoral radiographs coupled with software. Differences in the degree of curvature were regarded as straightening and canal curvature was evaluated based on Schneider technique using the AmScope software for measurements and compared between groups and levels of instrumentation applying Mixed-model ANOVA. Significance was set at 0.05.

RESULTS

Canal curvature tended to gradually straighten out as the level of instrumentation increased in all three groups without statistically significant difference among the groups (P = 0.826).

CONCLUSION

Overinstrumentation in curved canals resulted in straightening of the canal curvature.