(PR137) Smear Layer Removal by Irrigation Adjuncts: A Scanning Electron Microscopy Study

Objective: With the trend towards dentin conservation and minimally invasive endodontics, irrigation has become a more important aspect of root canal disinfection. This study compares the ability of two adjunctive irrigation modalities, the AdvErL EVO laser and the GentleWave Procedure, to remove smear layer from canal systems.

Methods: Forty maxillary and mandibular molars were accessed, the mesiobuccal canals were prepared up to apical size 25 using rotary instrumentation, then equally divided into 4 groups for irrigation: conventional needle, AdvErL EVO, GentleWave, andAdvErL EVO followed by GentleWave. The teeth were then decoronated and split longitudinally. One-half of each root was selected for preparation and analysis under scanning electron microscope. Evaluators rated the randomized images on a 4-point scale. Statistical analysis included the Kruskal-Wallis test and the Kappa statistics for agreement among raters.

Results: All three groups, the AdvErL EVO, GentleWave and AdvErL EVO followed by GentleWave, had similar average ratings. All three had higher average ratings than the conventional needle group.

Conclusion: Within the limitations of this study, the AdvERL EVO laser, the GentleWave Procedure and their combination were equally effective at removing the smear layer. They are all more efficacious than conventional needle irrigation.