Objective: Patients with periodontitis often have difficulty in maintaining oral hygiene with toothbrushes during treatment periods, especially for patients with severe conditions where brushing may cause bleeding of the gingiva and increase the chance of bacterial infection. Patients who have oral cancer, or who are bedridden long-term due to chronic diseases, also experience similar inconveniences in being unable to maintain oral hygiene through brushing their teeth and must do so through other means. Methods: We explored the method for dental washer, using the micro-bubble generator connect the ejection nozzle to an ergonomically designed soft teeth-tray that fits with the tooth configuration of a typical human oral cavity to clean oral plaque bacteria. Five levels of rotor speed and 4 type of ejection hole diameter, totally, were using 20 combinations to clean oral plaques bacteria. Results: Our results showed that with various combinations of motor speed settings and pore diameters, a clearing rate of 56% or more (average 79.55%) could be achieved, while in some combinations a clearing rate of 91.64% was possible. The nozzles with smaller diameters coupled with low speed motor had higher cleaning efficiency; the larger the diameter, the higher the volume and the larger the bubble dimensions and better bacteria removal. Conclusion: The experimental verification is effective by controlling ejection hole diameter and soft tooth-tray on better bacteria removal. For future, it is hoped that can definitely solve the dental hygiene issue for long-term bed-ridden patients who could not use toothbrush.