Work-related musculoskeletal disorders (MSDs) are a common occupational concern among dentists due to repetitive movements, prolonged static postures, and the use of vibrating instruments such as ultrasonic scalers. This study investigated the ergonomic risks associated with ultrasonic scaler use during dental prophylaxis among licensed Filipino dentists by evaluating vibration exposure, muscle activity, postural risk, and perceived discomfort. Vibration was measured using a tri-axial accelerometer, muscle activity was recorded through electromyography (EMG), and posture was assessed using the Rapid Upper Limb Assessment (RULA). Subjective comfort and discomfort ratings were also collected before and after task performance. Twelve female dentists performed standardized scaling procedures on a simulated dental model representing anterior and posterior regions of the upper and lower jaw. Results showed that several participants exceeded recommended vibration exposure thresholds, indicating potential risk for hand–arm vibration syndrome. Muscle activity analysis revealed elevated activation levels in several upper limb muscles during scaling tasks, particularly in posterior regions of the mouth. Postural assessment further indicated moderate to high ergonomic risk during these procedures. Participants also reported increased discomfort after task completion, especially in the neck, shoulders, and hands. Overall, the findings demonstrate that dental prophylaxis using ultrasonic scalers presents notable ergonomic challenges due to the combined effects of vibration exposure, muscular workload, and non-neutral posture. These results highlight the need for improved ergonomic awareness and preventive measures to support the occupational health of dental professionals.

Keywords

Occupational ergonomics, Musculoskeletal disorders, Hand-arm vibration, Dentists, Ultrasonic scalers, Oral Prophylaxis, Electromyography, Postural assessment