Measurement of Simulated Debris Removal Rates in an Artificial Root Canal to Optimize Laser‐Activated Irrigation Parameters

BACKGROUND AND OBJECTIVES: To compare temporal rates of debris removal from an artificial root canal for three laser‐assisted irrigation modalities single‐pulse super short pulse (SSP), and two dual‐pulse X‐SWEEPS and AutoSWEEPS, and for two fiber‐tip (FT) geometries flat and radial, and to evaluate the dependence of the debris flushing rate on the delay between the SWEEPS laser pulse pair. STUDY DESIGN/MATERIALS AND METHODS: Laser‐assisted irrigation was performed with a pulsed Er:YAG laser operating in single‐pulse SSP and dual‐pulse SWEEPS laser modalities. The laser energy was delivered to the water‐filled model access cavity through a FT with either a flat or radial ending. The X‐SWEEPS modality delivered pairs of laser pulses separated by a fixed adjustable delay, while with the AutoSWEEPS modality the delay was automatically and repeatedly swept between 200 and 600 microseconds. The debris removal rate was determined with the use of a digital camera by measuring the rate at which a simulated debris was being flushed out of the artificial root canal. RESULTS: The simulated debris removal rate of the AutoSWEEPS modality is almost three times higher compared with that of the SSP modality. Further, the flat FT outperforms the radial FT by a factor of more than five in the case of SSP, and by more than 10 with AutoSWEEPS. The X‐SWEEPS flushing rate exhibits strong dependence on the delay between the SWEEPS pulse pair, with the highest removal rate measured to be more than seven times higher in comparison with SSP. CONCLUSION: Dual‐pulse laser irrigation modalities (AutoSWEEPS and X‐SWEEPS) exhibit significantly higher simulated debris removal rates in comparison with the standard single‐pulse SSP laser‐assisted irrigation. As opposed to the previously reported dependence of pressure generation on FT geometry, the flat FT's simulated debris removal rate significantly outperforms the radial FT. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC