Dental plaque on the surfaces of implants causes peri-implantitis and periodontitis. Although the plaque needs to be removed from the surfaces, it is difficult to clean it from the screw section of an implant, as this is roughened to improve biocompatibility. Recently, a method using a cavitating jet was proposed to clean dental plaque. In this paper, the geometry of a Venturi type nozzle for a cavitating jet is optimized by measuring the cavitation impact using a PVDF (Polyvinylidene Fluoride) sensor. The cleaning performance of a cavitating jet using this nozzle is compared with that of a normal water jet. The results show that the optimum divergence angle is 15 deg or 20 deg, depending on the injection pressure. The effect of temperature on the impact power was also investigated, and it was found that the impact power increases with water temperature and saturates at 40-50 °C. It was demonstrated that a cavitating jet using the optimized Venturi type nozzle can remove dental plaque from the screw section of an implant and that the area cleaned by the cavitating jet is greater than that cleaned by a normal water jet.
- Dental plaque