ABSTRACT: Mechanical preparation of primary teeth root canals was associated with dentinal micro-cracks that might evolve into vertical root fracture compromising treatment success and shift treatment toward dental extraction. Consequently, the objective of current study was to assess and compare the dentinal crack formation of Kedo-SG Blue file and Wave-One gold to Stainless Steel hand K files after root canal preparation of primary molars.
Materials and methods: Seventy-five mandibular second primary molars with two separate and straight mesial canals were chosen and immersed in distilled water. Removal of coronal portions and distal roots of all teeth were carried out utilizing a diamond coated bur with water coolant. All teeth were randomly allocated into three groups (n=25 /each) according instrumentation file: (1) Kedo-SG Blue, (2) Wave-One Gold and (3) Stainless Steel hand files. Then, all specimen were cut perpendicular to the axis of tooth to coronal, middle and apical third, therefor, three slices were obtained from each specimen. Each slice was examined with Environmental Scanning Electron Microscope (E.SEM) to determine the presence/absence of cracks. Statistical analysis was carried out with R statistical analysis software version 4.0.3 for Windows.The level of significance was set at p ≤ 0.05. Results: The majority of samples instrumented with Kedo SG Blue 57(76.0%), Wave one gold 44(58.7%) and Stainless Steel k file 65(86.7%) were free of cracks.
Conclusions: Higher percentages of dentinal cracks were seen in the WOG group followed by Kedo-SG Blue group, with lowest percentages recorded for Stainless Steel hand K –files group.