The issue of noise pollution in the workplace—and possible associated hearing loss— is gaining more attention within the dental profession. John Burfitt reports
At first, the sight of the Sydney dentist putting noise plugs into his ears before commencing a standard scale and clean seemed, to this patient, like an overreaction.
“The noise from the handpiece machines along with the suction machine can get a bit overwhelming by the end of the day, so this is now one thing I do to reduce the problem,” explained the practitioner afterwards.
His action, it turns out, is not an overreaction at all. Dr Elizabeth Beach from the National Acoustic Laboratories at Sydney’s Macquarie University says the issue of noise levels in a dental clinic needs to be addressed by the industry.
“What’s interesting is the issue about noise within the dental workplace has come up before, and we’re seeing it coming up again, with dentists more open to discuss it,” Dr Beach says. “While I wouldn’t say there is any major danger with current levels, there are definitely things that can be done to reduce the noise, and that would be good across the profession.”
Occupational Safety and Health Act regulations for industry in Australia limit an individual’s exposure to steady state noise levels at 85 decibels (dB) across an eight-hour time period. According to a 2014 report in the Dental Research Journal from the Dental School of Damascus University, the majority of dental equipment can produce sounds of up to 92 dB for ultrasonic cleaners, 86 dB for ultrasonic scalers, 84 dB for stone mixers and 74 dB for low-speed handpieces.
The older and more worn the equipment, however, the more amplified the noise can be, even reaching levels of up to 100 dB.
Dr Beach says even with these standards, caution needs to be applied. “You need to remember this is a low-risk but not a no-risk,” she says. “If you are exposed to those noise levels every day over a 40-year career, some people will get hearing loss. There is now a bigger range of noise sensitivity and reduced loudness tolerance, which is why it’s important to consider strategies to deal with it.”
As anyone who has worked inside a dental practice can attest to, handpieces are one of the main sources of noise within a clinic. As the equipment ages and wears out, it’s usually noisier.
“This issue about noise was never raised when I was going through dental school, but we are hearing more about this now, and I think that’s important,” Dr Ky-Anh Nguyen, Associate Professor at the Sydney Dental School says.
“Equipment wears out, like when the ball bearings inside corrode and rattle, and you can tell the difference in sound. Rather than let it continue so it’s painful to listen to, it should be a sign the machine needs maintenance or it is time to replace.
“While I wouldn’t say there is any major danger with current levels, they’re definitely things that can be done to reduce the noise, and that would be good across the profession.”
Dr Elizabeth Beach, National Acoustic Laboratories, Macquarie University
“There are other noises that can be so high-pitched, like suction devices, that I have often wondered if anyone has thought of redesigning the piece so it reduces turbulent airflow and creates less noise.”
It’s a point Dr Beach picks up on. “At the next major dental conference when the manufacturers are showing off their latest innovations, dentists should be asking what they’re doing to reduce the noise of the equipment,” she says. “There should be a push for that, so that things are being done at the source that creates the noise. It would be good as a profession to put pressure on and say we will only buy this gear if we find the noise levels are safer to work with.”
Dentsply Sirona is the world’s largest manufacturer of professional dental products, and last year announced the development of new contra-angle handpieces and turbines that operate with lower sound emissions. The red contra-angle handpiece, offering a combination of optimum illumination and small heads, has ceramic ball bearings with a special diamond-like carbon coating to guarantee longevity. The company claims it’s one of the quietest on the market.
“It is very important to us to continue optimising our instruments, especially in terms of noise emission,” Jan Siefert, group vice president, at Dentsply Sirona (Instruments), explained in a statement. “We pay attention to both intelligent design and the precise manufacture of the individual components.”
It’s not just the mechanics but all sources of noise within the practice that need to be considered, Dr Beach adds. She says the best way to start is to complete a full inventory of what is making noise within the practice.
“Try not to have two pieces of noisy equipment going at one time, so if you are about to use the drill, you may turn the radio or stereo to silent at the same time. If you have a noisy air conditioner, it might also be worth getting someone in to see how that noise can be minimised.”
Dr Beach advises dentists to use earplugs or earmuffs during noisier procedures. “If you find you have a decreased tolerance to noise or the sound of one particular device causes stress, then invest in earplugs—it cannot hurt,” she says.
“Earplugs have different attenuation levels, so if a device creates a noise that is near 90 dB, then you might only need an earplug with a small noise attenuation of between five to 10 dB. Just be sure to find something that is comfortable and easy to use so it becomes as commonplace to use as putting on an eyepiece or mouth mask.”
Dr Beach says dentists should also get their hearing checked every two years. “Find out what is happening with your hearing so you have a baseline to work with,” she says. “Then it becomes something you can monitor over time, and also address.”