In vitro evaluation of Kedo-S and RaCe rotary files compared to hand files in preparing the root canals of primary molar teeth

Background and aims: Considering the advantages of rotary files in instrumenting the root canals of permanent teeth and a lack of adequate data on the use of these systems in primary teeth, the present study aimed to evaluate two rotary files and compare them with hand files in the cleaning efficacy of the root canals of primary molar teeth. Materials and methods: In the present study, three groups of teeth were prepared with Kedo-S paediatric rotary file system, RaCe (reamer with alternating cutting edges), and hand files (n = 40). The groups were evaluated under a stereomicroscope concerning the cleaning efficacy of the files after cleaning the teeth in the apical, middle, and coronal thirds. The data were analyzed with SPSS 24 (IBM Corporation, USA, 2016) using Fisher's exact test and chi-squared test; statistical significance was set at p < 0.05. Results: There were no significant differences in the apical and middle thirds between the different study groups. However, there were significant differences in the coronal third between the hand file and Kedo-S (p = 0.016) and RaCe and Kedo-S (p = 0.001) groups. Conclusions: The present study showed that Kedo-S files were more effective than RaCe and hand files in the coronal area than the hand and RaCe files.