Evaluation of the removal ability of Iodoform Paste in primary teeth pulpectomies using rotary files: a pilot study

The aim was to analyse the efficacy of Endogal Kids® rotary files in removing root canal filling. Methods: A cross-sectional in vitro study was conducted (n = 10 primary teeth). The root canals were instrumented using the Endogal Kids® system with 5 mL of 5% sodium hypochlorite solution and were obturated with CaOH2 and iodoform paste, Forendo™ Paste. The canal systems were retreated to remove the filling material using continuous rotation. µCT scans were performed at three time points: after canal instrumentation with rotary files (µCT-1), after root canal filling (µCT-2), and after removal of the filling material through retreatment (µCT-3). Canal void volume (CV), obturation material volume (MV), root canal void increase (ΔCV), obturation material increase (ΔMV) and filling removal volume (RV) were calculated. Statistical analysis was performed with a 95% significance level (p ≤ 0.05). Results: Significant differences were found for CV and MV, but not for TV. The canal void volume (CV) was significantly greater at µCT-1 compared to the µCT-2 and µCT-3, with no significant difference between the µCT-2 and µCT-3 (p < 0.001). Additionally, MV was significantly higher before removal of the filling material (p = 0.003). No significant differences were observed in TV across the three measurements. Conclusions: This pilot study demonstrated that rotary instrumentation in primary teeth can remove a significant proportion of iodoform-based obturation material. Incisors showing greater obturation material removal, while molars exhibited more pronounced changes in canal volume.