Sustainability in dentistry: Part 1 - Plastics and biodegradability

By Emeritus Professor Laurence J. Walsh AO

In the first part of this series of articles on sustainability in dentistry, the focus is understanding plastics, especially biodegradable plastics and the issues around recycling of plastics. Later instalments will address other topics within sustainability, including using the life cycle analysis (LCA) to compare different options for equipment and materials and how facility design can enhance sustainability in dental practice.

Understanding this topic links to the newly published (July 2023) updated Australian Dental Council statement of the expected competencies for new graduates from dental education programs of any type, which includes as a core competency the need to “recognise the environmental impacts of health care provision and use resources responsibly, making decisions that support environmentally sustainable healthcare”

Which plastic is what?

Table 1 provides a list of common plastic materials, dividing these into the fossil-based varieties and those that are biologically-based polymers, also known as bioplastics. Note that this term bioplastic does not necessarily mean that a biologically-based plastic will be more sustainable than a fossil-based plastic. Adding to the complexity around this topic is inconsistent labelling regarding the features of various types of plastics, contradictory information regarding their LCA and “greenwashing” where the product labelling is misleading.

There are many single use plastic items used in dental practices. Plastics are also used in the packaging of items, in PPE and in sterilisation pouches (Table 1). Each of these plastic materials has different properties (physical strength, flexibility, permeability, etc) that reflect its unique chemical structure, specifically what monomer has been used as the building block in the polymer.