Experimental correlation between tip vibration dynamics and aerosol generation in dentistry

Dental ultrasonic scaling generates bioaerosols that can carry respiratory pathogens and contribute to airborne transmission risk, yet the physical parameters governing their generation remain poorly quantified. Here, we experimentally quantify the effects of ultrasonic scaler tip geometry, vibration amplitude, and contact angle on aerosol generation for cooling water and artificial saliva. Empirical correlations were developed for the aerosol generation rate, and a normalized Ohnesorge-number scaling captured the droplet-size dependence. Among the tested tips, the smallest diameter produced the highest aerosol generation rates and release velocities. Remarkably, once normalized, data from different tips collapsed onto a single Ohnesorge-based master curve, indicating that tip geometry primarily sets the absolute aerosol yield while leaving the relative size distribution nearly unchanged. Tip geometry and vibration amplitude were the dominant factors influencing aerosol generation, whereas contact angle played a comparatively minor role. These findings advance the quantitative understanding of aerosol generation during ultrasonic scaling and provide a physics-based basis for aerosol emission prediction and transmission risk assessment in dental settings.