Study of Hand-Arm Vibration Exposure and Its Health Effects in Dentist Employed in Academic Clinics

Background & objectives: Exposure to hand- arm vibrations is one of the occupational risk factors for employing dentist manual tools. This study aims to determine the exposure level to vibration and its related health effects in dentists employed in academic clinics. Methods: This study was conducted on 30 dental practitioners as a case group and 30 employees at the clinic who were not exposed to vibration as a control group. Hand-arm vibration was measured using the SVANTEK 106 vibration meter in accordance with ISO 5349 standard. The level of musculoskeletal complications was determined using the hands grasping and finger grip strengths and finger dexterity. The level of neurosensory disorder was determined by the monofilament test. Data were analyzed using SPSS 16 software. Results: The mean of equivalent exposure level to vibration for 8 working hours was 0.65 m / s 2 for dentists which are lower than the national exposure limit. Feeling of needle punching was the most commonly reported symptom (47.5%) among dentists. The levels of handgrip strength, fingers' strength and dexterity of dominant hand were decreased 22 % ( p <0.05), 8% ( p <0.05) and 2 % ( p >0.05), respectively in case group compared to control group. The fingers sensory threshold of dentists was higher than the control group and in the dominant hand of the case group was higher than their non-dominant hand ( p <0.05). Conclusion: Despite the low level of exposure to vibration, a level of disability was observed in the physical and neurosensory function of dentist’s hand. The prevalence of neurosensory disorder was also more than musculoskeletal symptoms.