Noise-induced hearing loss in the military dental setting: a UK legislative perspective

Health professionals working in the dental environment are potentially at risk of noise-induced hearing loss (NIHL) due to the use of clinical and laboratory equipment. Workplaces engaging in the practice of dentistry within the UK are subject to legislation from the Control of Noise at Work (CNW) regulations 2005. Clinicians working in the military are at further increased risk of NIHL due to exposure from additional risk factors such as rifles or aircraft engines. To our knowledge, no authors have previously studied the noise levels experienced in a military dental setting or compared noise levels in a typical dental practice with current UK legislation.

Measurements of noise levels experienced by a dentist, dental nurse and dental hygienist during a standard conservation procedure were assessed using wearable noise dose-badges. Furthermore, noise levels within a dental technician's work space were also assessed. Noise levels produced by representative clinical and laboratory equipment were assessed and compared with CNW legislation.

The highest level for clinical equipment was produced by the suction apparatus while aspirating up a cup of water at 76 dB. For laboratory equipment, the lower exposure action value (LEAV) of 80 dB would be exceeded in 2.1 hours' use of the trimmer, 3.6 hours' use of the vibrating table and 9 min use of the airline.

Noise levels experienced by clinicians within the dental surgery were well below the legislative LEAV thresholds for both peak and continuous noise. However, noise levels produced by laboratory equipment were far higher and there is clearly the potential for excessive noise exposure for dental professional in the everyday setting. Dental professionals responsible for dental laboratory settings must be familiar with the CNW regulations and measures put in place that control the inadvertent breach of legislation. Hearing protection must be mandated when using equipment that exceeds the LEAV and an educational programme is required to explain both their correct use and the rationale behind it. Methods of mitigating that risk further require exploration such as alternative methods of completing the tasks performed by the airline or reducing the noise generated by it, such as by reducing the supply pressure or using an alternative nozzle design.