Resident University of the Pacific Arthur A. Dugoni School of Dentistry Walnut Creek, California, United States
Objective: The purpose of this study was to investigate the efficacy of a novel laser that does not utilize sodium hypochlorite (LEAP) as a final irrigation protocol compared to GentleWaveR, standard needle irrigation and ultrasonic activation methods. Materials &
Methods: Single canal human premolars were instrumented and autoclaved. Canals were incubated with E. faecalis for 21 days. Teeth were randomly divided into four groups (n=15) and disinfected using either standard needle irrigation (SNI), ultrasonic activation (PUI), LEAP (LP), or GentleWaveR (GW). Canals were sampled prior to (S1) and after (S2) the final irrigation protocol. Bacterial viability in the main canal was determined via culturing. Additional samples from each group were analyzed using confocal laser scanning microscopy (CLSM) to determine bacterial viability within the dentinal tubules.
Results: All S2 samples showed significant bacterial reduction compared to S1 (p < 0.05). Quantitative analysis demonstrated bacterial reduction of: SNI (98.9%), PUI (99.9%), LP (99.3%), and GW (99.9%). CLSM showed various irrigation penetration depths among the coronal, middle and apical segments of the canals.
Conclusion: LEAP and GentleWaveR demonstrate capability to disinfect the main canal space as well as the dentinal tubules. Statistical analysis: Kruskal Wallis test will be used to determine log reduction. For CLSM, the percentage of red to green will be calculated as a percentage of red and green intensity. ANOVA will be fit for treatment groups, locations, and penetration depths. Pair-wise comparisons will be performed.
