The purpose of this study was to compare the shaping ability of three Ni-Ti file systems used by dental students or the experts and consequently to aid in choosing a proper systems for educational courses of dental students and beginners.

Fifty students and ten dentists who have clinical experience over two years prepared 180 simulated root canals in resin blocks with three Ni-Ti systems; ProFile® (PF), HeroShaper® (HS), K3^TM (K3).

After preparation, the Ni-Ti files were evaluated for distortion and canal preparation time was recorded. The images of pre- and post-instrumented canals were scanned and superimposed. Amounts of increased canal widths, deviation, and centering ratio were calculated at apical 1, 3 and 5 mm levels and statistical analysis was performed.

The results were as follows:

HS showed the shortest preparation time and instrumented canal width in K3 was significantly larger than other groups (P < 0.05).

Based on the results, it is surmised that the ProFile® is the safest and most ideal instrument for students and beginners.

The purpose of this study was to compare and evaluate the shaping ability of the three different Ni-Ti file systems used by undergraduate students.

Fifty undergraduate students prepared 150 simulated curved root canals in resin blocks with three Ni-Ti file systems - ProFile® (PF), Manual ProTaper® (MPT), Rotary ProTape® (RPT). Every student prepared 3 simulated root canals with each system respectively. After root canal preparation, the Ni-Ti files were evaluated for distortion or breakage. Assessments were made according to the presence of various types of canal aberrations. The pre- and post-instrumented canal images were attained and superimposed. The instrumented root canal width were measured and calculated for the net transportation (deviation) and the centering ratio.

Under the condition of this study, both ProTaper® systems allowed significantly more removal of root canal wall than the ProFile® system. In the important other aspects such as the centering ratio, there was no significant differences between the systems. Novice dental students were able to prepare curved root canals with any kinds of Ni-Ti file systems with little aberration and great conservation of tooth structure. Students want to learn effective methods and at the same time simple rotary procedures. The rotary ProTaper® systems were one of the most compatible to these students from the point of view of cutting ability. The ProFile® system was also compatible in safe and gentle shaping.