Efficacy of the NaviTip FX Irrigation Needle in Removing Post Instrumentation Canal Smear Layer and Debris in Curved Root Canals

IntroductionThis study evaluated the effectiveness of the NaviTip FX (Ultradent Products Inc, South Jordan, UT), a 30-gauge brush-covered irrigation needle, in removing debris and smear layer in vitro.MethodsForty mesio-buccal maxillary and mandibular first molar root canals with 20° to 30° curved roots were randomly divided into four groups (n = 10). The irrigation protocol after cleaning and shaping was as follows: NaOCl/EDTA/nonbrushing (NaED) group: passive use with 5.25% NaOCl followed by 17% EDTA and saline; EDTA/brushing (EDBr) group: passive use with 5.25% NaOCl followed by left and right manual rotary up and down brushing using 17% EDTA and a saline rinse; EDTA/FileEze (Ultradent Products Inc)/brushing (EDFEBr) group: same as EDBr, however, with FileEze; and control group (CG): a standard 30-gauge NaviTip irrigation needle used passively. The roots were split longitudinally and the canals examined in a scanning electron microscope. Debris and smear layer were recorded at 1, 5, and 10 mm from the working length (WL) using a three-step scoring scale and 300-μm square grid. Mean scores were calculated and statistically analyzed (p < 0.05) between and within groups.ResultsComparison between groups revealed that at all evaluation levels EDBr and EDFEBr groups were significantly cleaner (p < 0.05) than NaED and CG, with no significant difference between them. Comparison within groups did not show significant differences (p > 0.05). All groups showed significantly better smear layer removal (p < 0.05) at 5 and 10 mm from the WL. The EDBr group exhibited no significant differences (p > 0.05) between the three evaluation levels.ConclusionIn moderately curved root canals, a NaviTip FX used with 5.25% NaOCL and 17% EDTA solution with manual brushing as well as the same method augmented by FileEze was the most effective cleaning protocol.