Volume 9 • 2022 • Issue 4

The idea for the study came out of a conversation with Dr. Brett Duane at Trinity College Dublin and Dr. Paul Ashley at the Eastman Dental Institute at University College London. “There were several bamboo toothbrushes coming on the market that were labeled as ‘eco-friendly’ or ‘sustainable,’ but there is no standard for this kind of labeling,” Dr. Lyne says. “Companies don’t have to back up those claims with evidence and we wondered if they were true.” In Canada, there are some environmental labels that are independently certified, such as the Canadian EcoLogo, but not all environmental claims on packaging are tested or certified. The land used to grow bamboo for toothbrushes could be better used to grow forests to offset carbon emissions. The research collaborators performed another study and found that the most sustainable toothbrush is one made of recycled plastic. 2 “If it’s recycled and recycled properly, plastic is actually not a bad material,” she says. “It’s just when it gets lost from the recycling system that it’s bad.” Dr. Lyne and her team undertook life cycle assessments comparing the impact of sterile surgical gloves (latex and non-latex) and non-sterile examination gloves. They found that examination gloves were 10 times more sustainable than surgical gloves. 3 “We used the results of that study to drive clinical change in our hospital department, and, since October 2021, we’ve reduced our surgical glove use by 50%,” she says. She also noted that macro level sustainable dentistry should always be considered. “We’ve been measuring how preventative measures, like community water fluoridation, helps protect the environment,” she says. “Population level interventions to prevent tooth decay are good for sustainability.” Dr. Lyne and her team’s work on these topics is expected to be published in the BDJ later this year. References: 1. Lyne A, Ashley P, Saget S, CostaM, Underwood B, Duane B. Combining evidence-based healthcare with environmental sustainability: using the toothbrush as a model. Br Dent J . 2020;229(5):303-09. 2. Duane B, Ashley P, Saget S, Richards D, Pasdeki-Clewer E, Lyne A. Incorporating sustainability into assessment of oral health interventions. Br Dent J . 2020;229(5):310-14. 3. JamalaH, Lyne A, Ashley P, Duane B. Non-sterile examination gloves and sterile surgical gloves: which are more sustainable? J Hosp Infect. 2021Dec;118:87-95. While gathering data for the life cycle assessments, the research team was surprised by some of what they learned. “We expected electric toothbrushes to be less sustainable because of the materials it includes such as a motor, charger and plug,” Dr. Lyne says. “But the biggest contributing factor to its environmental footprint comes from transporting the product itself. It is quite heavy compared to the weight of a manual toothbrush and just shipping it from Europe to the United Kingdom released a lot of carbon.” The electric toothbrush had the greatest environmental impact in 15 out of 16 categories of the life cycle assessment. The bamboo and replaceable-head toothbrushes had the lowest impact in all 16 categories. “Doing a life cycle assessment, you see that there are always trade offs,” says Dr. Lyne. “No product is perfect. Bamboo requires water, land and fertilizers that all have negative impacts on the environment. Bamboo does well in some categories but it isn’t a magic bullet.” A life cycle assessment includes factors like water use, land use, toxicity and effects on biodiversity and human health. There are always trade-offs, no product is perfect. (L. to r.): Dr. Brett Duane, Dr. Alexandra Lyne, Dr. Paul Ashley 25 Issue 4 | 2022 | Issues and People