ABSTRACT
Context: Cleaning and shaping of the canals damages the root dentin which becomes a gateway to dentinal cracks and thereby causes failure of the treatment. Aim: The aim of this study was to assess and compare dentinal crack formation caused by three different nickel–titanium (NiTi) rotary file systems in primary anterior teeth. Settings and Design: The present in vitro study is an experimental, comparative study. Materials and Methods: One hundred fifty extracted primary anterior teeth were included in this study. The teeth were randomly divided into five groups. Group 1: Pedoflex rotary file system, Group 2: Prime Pedo™ rotary file system, Group 3: Kedo-S2 rotary file system, Group 4: K-files, and Group 5: no instrumentation. Roots were sectioned and viewed under a stereomicroscope for the presence of any cracks. Statistical Analysis Used: The data were analyzed using the Chi-square test and Kruskal–Wallis test. Results: In the coronal, middle, and apical thirds, Group 2 showed a maximum number of crack formations in the middle third (57%), followed by Group 3 (43.3%) and Group 1 (36.7%). Groups 4 and 5 showed no crack formation in all the root sections. The middle third showed a maximum number of crack formations compared to the coronal and apical thirds. Conclusions: Rotary systems render various benefits with an acceptable success in comparison to conventional hand instrumentation. Within the limitation of this study, it was found that Pedoflex rotary file system was the best with the least number of crack formations.
ABSTRACT
Objective@#This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique.@*Methods@#Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test.@* Results @# The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature.@*Conclusion @# With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.