All smiles: Transforming dental treatment for tamariki and dentists alike
23 May 2024 | Read time: 7 minutes
Tooth decay is the most common chronic childhood disease in Aotearoa New Zealand. Despite significant improvements in national oral health in recent decades, four out of ten 5-year-olds are still affected by cavities (also called dental caries).
The typical treatment for caries in children is to ‘drill and fill’ or cap the affected tooth with a pre-formed stainless-steel crown, bonding it using glass cement. Though effective in many instances, this process, known as the Hall Technique, has limitations. Standard commercially-available crowns often don’t fit New Zealand childrens’ teeth, but making the necessary adjustments to them takes time and can cause the bond or the crown to fail. In addition, the use of a shiny metal means that crowns are conspicuous in the mouth.
SfTI Seed researcher, Dr Joanne Choi, based at the University of Otago is transforming our approach to childhood caries. With SfTI support, she and her team have developed white crowns that are strong and malleable, more affordable (and profitable) than standard metal crowns, and which seamlessly blend in with a child’s other teeth.
At the heart of this development is a unique polymer material for which Choi has submitted a patent application. The dental resin typically used to make fillings or crowns is brittle and can shatter. In contrast, this new polymer is flexible yet robust enough to withstand chewing forces in the mouth for two years. It can also be processed by injection moulding or compression moulding.
Crucially, these ‘Snow Cap Crowns’ have benefits for dental practitioners, too. They can be fitted by clinicians or dental therapists using the same tools and processes as the Hall technique; no drills or injections required. And as a result of a large study led by Choi, in which the dental scans of more than 230 tamariki were collected and analysed, the crowns are designed to suit the specific needs of New Zealand’s children.
“When you look at the history of development of the dominant metal crowns on the market, they’re scaled-up and down from the tooth measurements of a single child in the US,” explains Choi. “Our research, combined with feedback from clinicians, has shown that these crowns don’t work for our population. We see a wide variety of tooth morphology here in general, and Māori and Pasifika children tend to have bigger teeth than European children.” By taking an equitable, NZ-led approach, Choi is developing a product that solves key issues faced by underserved patients and dentists, alike.
“When you look at the history of development of the dominant metal crowns on the market, they’re scaled-up and down from the tooth measurements of a single child in the US,” explains Choi. “Our research, combined with feedback from clinicians, has shown that these crowns don’t work for our population. We see a wide variety of tooth morphology here in general, and Māori and Pasifika children tend to have bigger teeth than European children.”
The reception from stakeholders has been overwhelmingly positive, as shown by Choi’s survey of 50 kiwi clinicians and 20 opinion leaders from the US, EU and Australia. When asked if they would choose a white crown over a metal crown if given both options, 100% of respondents said ‘Yes’. One clinician wrote, “The Hall Technique is by far the most child-friendly option. The main reason parents decline is the silver appearance, and they all ask why we don’t have a white option!” Professor Margherita Fontana from the University of Michigan, said “This will increase access to more vulnerable populations who cannot afford current aesthetic options.”
The next stage in Choi’s work is a randomised clinical trial, run in collaboration with Te Whatu Ora Southern. 60 children with dental caries will be recruited, with 30 receiving normal metal crowns, and 30 receiving Snow Cap Crowns. Participants will have follow-up appointments three and six months later, to check on the crowns. “We will also collect data on how long it took for each clinician to place our new crown, so that we can have a comparison with the metal ones,” says Choi. “And we’ll ask questions about materials and design. That’ll allow us to optimise everything for the launch of the product.”
Moving towards commercialisation has been a core focus of Choi’s SfTI Seed project. She first came across the program as an Emerging Innovator for KiwiNet, and says it felt like a perfect fit for her and her team. “The funding meant we could focus instead of scrambling every quarter. Beyond that, SfTI really invested in us, and enabled us to develop and upskill. I was an academic who didn't understand the language they use in the business world. I’ve since attended workshops and events that have really changed our trajectory.”
One example she cites is her attendance at the International Dental Show in Germany in 2023. “It’s where all the dental companies launch new products and technologies. It was very eye-opening for me to attend a trade show rather than a research conference. I got to network with founders, and talk about things like manufacturing and regulatory processes, and discuss what’s needed to expand beyond New Zealand.”
The better aesthetics, cost-effectiveness and ease-of-use of Choi’s Snow Cap Crowns means that their potential reach in NZ and overseas dental markets is significant.
SfTI Director, Sally Davenport, said that this project was identified as one of the SfTI projects closest to market.
"We selected this project as one of a portfolio of SfTI projects for independent economic assessment, and this really clarified the huge potential this technology has. This venture is expected to have revenues in the order of $10-$20 million within its first two years of operations and the be in the order of $100 million in revenues within 5 years. When we look at this in the context of SfTI’s total fund of $106 million allocated over ten years, the revenue from this one technology will surpass our total SfTI fund in under 5 years.”
We selected this project as one of a portfolio of SfTI projects for independent economic assessment, and this really clarified the huge potential this technology has. This venture is expected to have revenues in the order of $10-$20 million within its first two years of operations and the be in the order of $100 million in revenues within 5 years. When we look at this in the context of SfTI’s total fund of $106 million allocated over ten years, the revenue from this one technology will surpass our total SfTI fund in under 5 years.”