Melissa, who completed her undergraduate degree at Queen Mary University of London, was supervised for her final project on dental materials by Professor Robert Hill, head of the Dental Physical Sciences Unit at Queen Mary and the developer of BioMin® F. Professor Hill was so impressed with Melissa’s work as an undergraduate that he was keen to encourage her to continue her work on bioactive glasses and investigate potential dental profession material applications of the BioMin F technology. He persuaded BioMin’s CEO Richard Whatley that the company should sponsor Melissa’s research for the duration of her three-year PhD studies. The title of her project is ‘Fluoride-containing bioactive glass to be used in dental restorations.’
The concept is self-evident: as we move away from the use of amalgam for dental fillings, the challenge for dental materials manufacturers has been to develop new materials that are as easy to handle, effective and, importantly, last a long time. The current life expectancy of a composite resin posterior restoration is around seven years, whereas amalgam lasts probably three times as long. So, in developing new materials, it’s essential to try to replicate the longevity of amalgam as much as possible, otherwise the overall cost of dental treatment will increase considerably.
Melissa is now coming to the end of her first year and, although she hasn’t been able to get into the lab for two months due to lockdown, she is excited about the progress she is making.
‘A lot of dental materials used for fillings tend to fail due to polymerisation shrinkage causing a gap where bacteria can penetrate,’ she said. ‘After doing a lot of research into bioactive glass, I was interested in the potential of their bioactive properties.’ The principle of the glass gradually releasing fluoride and other mineral ions to raise the local pH to create an environment which bacteria do not favour, and to form fluorapatite, is similar to that of BioMin F toothpaste, but the glass composition has to be different. Melissa has spent several months developing different types of bioactive glass to find the most suitable for incorporation into a resin for posterior composite filling materials and is now ready to test them out. The intention is that the bioactive glass can be incorporated into a commercial resin and used for filling materials.
This PhD research is an important step in Melissa’s own career path. After graduating, she went to work in Dentsply’s research labs in Germany, but soon realised that the senior staff there all had doctorates, and she decided to study for a PhD. ‘I knew I wanted to work in the dental industry,’ she said. ‘I chose to work and gain experience rather than take an MA, but I quickly saw that in order to progress I needed a PhD.’
She’s undecided now as to whether to go into industry after the doctorate is completed, or stay within university scientific research, so she’s keeping her options open. ‘I’m still considering academia so I am publishing papers,’ she said.
Once the lockdown opens up, Melissa will be back in the lab, working on her glass technology, but it will take some time, and many lab and clinical trials, before a composite that contains fluoride bioactive glass is commercially available. A material that can ‘self -repair’ by remineralising the area around it is, however, a very exciting prospect.