Can bio-tech dentistry ease pain?
The No Drill, No Fill project might change the way tooth problems are dealt with. Will Harvie reports on the research being carried out in New Zealand.
We’ve all been in a dentist’s chair, wriggling in discomfort. A cavity is being drilled – that strange combination of high, painful whine, spraying water and too many fingers in the mouth.
It’s no surprise, then, that researchers and entrepreneurs are seeking new ways to deal with cavities, decay, trauma and other tooth problems. One line of research suggests stem cells can be coaxed into forming new tooth materials. Another approach suggests a drug developed to treat Alzheimer’s disease can stimulate the tooth to heal itself.
In New Zealand, researchers have taken a different tack and are hoping bio-mimicry can change dentistry.
Drs Azam Ali, Lavanya Sharma and Karl Lyons of the University of Otago call it the No Drill, No Fill project and recently got a $150,000 explorer grant from the Health Research Council (HRC) to develop their ideas over two years.
Worldwide, the predominant current treatment for cavities is to drill out the damaged tooth material and fill the resulting hole with an inert amalgam or composite resin. Whatever the substance, it replaces lost tooth structure but not the mineralisation of natural tooth matter.
In simple terms, a human tooth is made up of four components. The outermost material is a crown of enamel. Beneath the enamel is a semi-hard material called dentine. Under the dentine is a softer material called pulp. Within the pulp are blood vessels and nerves.
Acid created by oral bacteria causes tooth decay, demineralises teeth and creates cavities or holes in the enamel, Ali says. The dentine is exposed and eventually the pulp. These ‘‘caries’’ cause discomfort and pain and, if left untreated, will eventually destroy the tooth.
Drill and fill removes the rot but the filled cavities can degrade over time and need replacing.
The Otago team’s No Drill, No Fill project aims to skip both processes. Instead, the researchers are investigating materials that would be implanted into the cavity or hole and potentially ‘‘regrow’’ the tooth.
‘‘This project aims to develop a biomimetic system with a combination of locally sourced natural polymers and bioceramics that can restore and potentially trigger remineralisation and regrowth of dental tissues,’’ wrote Ali in an HRC summary of the research.
At this early stage, the research looks to restore dentine and some enamel but in theory it might be possible to regrow all components of a tooth, Ali says in an interview. But that could be five to eight years away or longer.
The Otago team are still in a chemistry lab working with a ‘‘collagen like material’’ that Ali declines to discuss further because the material and techniques – if they work – might have substantial commercial value.
He has previously said collagenlike materials would mimic the cells while bioceramics, consisting largely of calcium phosphate, would provide the hardness teeth require.
They are currently trying to ‘‘precisely design the molecules’’ that would be implanted, he says. This work is taking place at the nano level. ‘‘There’s still a lot of chemistry to be done on that,’’ Ali says, speaking on behalf of the research team.
But they have ‘‘quite a bit of confidence’’ that phase one work will be successful. If so, they hope to advance to animal teeth and, if that works, to human teeth.
Ali, a senior lecturer in the Department of Applied Sciences, specialises in biomaterials science and engineering. He’s been granted patents for wound care medical products, bone void fillers and the like.
Many of these utilise keratin, a fibrous structural protein found in wool and skin.
It is, Ali has written, useful because it degrades after fulfilling its function. He said the collagenlike material under investigation for No Drill, No Fill could perform in a similar manner because the process needs to cease once the cavity is restored.
His recently published papers investigate the use of dairy byproducts for non-food biomaterials, the use of keratin to support the growth of dentine-like cells, and using squid and crab extracts for bone-tissue engineering.
He is not a tooth specialist (although his team includes them), his speciality is biomaterials and biomedicine .
The research looks to restore dentine and some enamel but in theory it might be possible to regrow all components of a tooth.