Evaluation of radicular dentin thickness in primary molars using rotary kedo-sg nano plus and manual k-files: a stereomicroscopic study

Background: Pulpectomy is a key procedure for retaining primary teeth affected by irreversible pulp pathology. Due to the delicate and complex root anatomy of primary teeth, preserving radicular dentin during canal preparation is essential. In recent years, pediatric nickel–titanium (NiTi) rotary systems have been introduced as a promising alternative to conventional hand instrumentation. Aim: To comparatively evaluate radicular dentin thickness and canal shaping characteristics following instrumentation with manual K-files and Kedo-SG Nano Plus rotary files in primary molars using stereomicroscopic assessment. Materials and Methods: An in vitro study was conducted on 40 extracted primary molars, which were randomly assigned into two groups (n = 20 each). In Group I, canal preparation was performed using stainless steel K-files, while in Group II, Kedo-SG Nano Plus rotary files were used. After standardized instrumentation and irrigation procedures, the samples were sectioned at coronal, middle, and apical thirds. Radicular dentin thickness was measured under a stereomicroscope. Statistical analysis was carried out using an independent t-test, with the level of significance set at p < 0.05. Results: Teeth instrumented with rotary files exhibited significantly higher remaining dentin thickness at all evaluated levels compared to those prepared with manual K-files (p < 0.001). Manual instrumentation resulted in comparatively greater dentin removal and less uniform canal morphology. No instances of instrument fracture or deformation were recorded in either group. Conclusion: Kedo-SG Nano Plus rotary instrumentation demonstrated enhanced preservation of radicular dentin along with improved canal shaping when compared to manual K-file techniques. These findings indicate that rotary systems may provide a safer and more efficient approach for pulpectomy in primary teeth.