A small peptide can fill in damaged human tooth enamel, a new study shows. The peptide could be placed into clinical products such as gels or toothpastes to restore early stage dental cavities, say the researchers.
Dental caries or cavities form when acid produced by bacteria dissolves the hydroxyapatite mineral (HAp) of which tooth enamel is mainly comprised. Fluoride-treated water and toothpaste impede this process by forming a new, but harder mineral – fluorapatite – to incorporate into the tooth surfaces. But this approach has attracted some controversy.
The short peptide could potentially offer a superior approach for certain applications, the researchers believe. US scientists at the University of Washington, Seattle, hit upon the discovery after investigating peptide sequences, from a native enamel protein called amelogenin, that mimics HAp and repairs damaged teeth that have lost their mineral. They identified a 15-amino acid peptide that could form a mineral layer on extracted human teeth (ACS Biomater. Sci. and Engin., doi: 10.1021/acsbiomaterials.7b00959).
A remineralisation procedure was run in the lab using the peptide, along with calcium and phosphate ions, in the presence or absence of fluoride. The amelogenin-derived peptide caused remineralisation and facilitated the incorporation of fluoride ions into the enamel.
‘These peptides are proven to bind to tooth surfaces and recruit calcium and phosphate ions,’ says Deniz Yuceso, a doctoral student at the University of Seattle. The peptide-enabled technology allowed 10 to 50 micrometres of enamel to be deposited onto a tooth. It could allow people to rebuild and strengthen tooth enamel on a daily basis as part of preventive dental care, say the researchers.
The studies were done in a dish in the lab, and the procedures need to be further optimised. For use in patients, there is a need to develop an easy-to-apply, fast-growing enamel-like biomineralised tissue for tooth repair.
‘This looks like one of the first studies to develop an in vitro model with human teeth [to remineralise dental caries],’ comments Paul Ashley, dental researcher at University College London Eastman Dental Institute. However, he notes there is a bit of a way to go before patients will see benefits. ‘There needs to be a lot more developmental work to quantify the effect, dosing etc. Then thought would have to be given to methods of application, and it would need to be trialled [in patients].’
According to the World Health Organization, dental cavities impact nearly every age group and are accompanied by serious health concerns. Moreover, direct and indirect costs of treating dental cavities and related disease are a large economic burden for individuals and healthcare systems.