How dental sensitivity can be improved with BioMinF
Dentine sensitivity, causing discomfort and pain, particularly in reaction to hot or cold food or drinks, is a common problem. Mainly affecting people aged 40–60, though sufferers can be of any age, the condition is caused when the enamel surface of the tooth is worn away or damaged, exposing the dentine layer. Hot or cold fluids trigger flow through the dentinal tubules, stimulating the exposed nerve endings in the pulp chamber and thereby causing sensitivity. Sensitivity is most common at the gingival margin and where gingival recession has exposed the tubules, or it can be due to erosion of the enamel, which is very thin in this area.
A wide variety of specialised toothpastes and products are available over the counter or on prescription for the treatment of dentine sensitivity, but a new solution has been found to the problem: a bioactive glass that acts with the saliva in the mouth to remineralise tooth enamel, occluding the dentinal tubules and effectively preventing sensitivity.
How BioMinF works
BioMinF is one of a new generation of bioactive glasses, which were initially introduced for bone grafting. These new glasses, incorporating other components within their structure, are now being applied in the dental industry. BioMinF toothpaste was developed by Prof. Robert Hill and his team at the Institute of Dentistry at Queen Mary University of London, and the bioactive glass it contains delivers a combination of calcium, phosphorus and fluoride ions as it dissolves. This combination promotes effective remineralisation of the enamel through the production of fluorapatite, the fluoride analogue of natural tooth mineral. Unlike conventional toothpastes that contain soluble fluoride, the fluoride component of BioMinF is incorporated within the structure of the glass and so is delivered gradually over up to 12 hours as the glass dissolves.
Besides its fluoride component, BioMinF contains a higher phosphate content than the previous generation of bioactive glasses, such as NovaMin, which form hydroxyapatite in the mouth. The increased phosphate content of BioMinF aids both the effectiveness and the speed of remineralisation. As the calcium, phosphate and fluoride ions are released, these work in concert with the saliva in the mouth to restore equilibrium after acid attack, forming fluorapatite, which is more stable and resistant to acid than hydroxyapatite is.
Tests using a nuclear magnetic resonance spectrometer have demonstrated that the fluoride in BioMinF is converted to fluorapatite in around 6 hours in a buffer, but as quickly as within 45 minutes in artificial saliva, and the remineralisation process continues for around 12 hours, with residual activity for up to 24 hours. At a lower pH, after consumption of an acidic drink, for example, BioMinF dissolves more rapidly to restore the equilibrium and prevent demineralisation.
Importantly for the treatment of sensitivity, the glass needs to dissolve directly on the tooth surface, so BioMinF contains a polymer that bonds it to the calcium in the tooth enamel, holding it in place for several hours while the calcium, phosphate and fluoride ions are released. The size of the glass particles is extremely small compared with that of NovaMin particles, enabling the glass particles to enter the dentinal tubules (1–5 μ in diameter) to occlude them and prevent fluid flowing through them.
Fluorapatite forms preferentially on the apatite-rich walls of the peritubular dentine within the tubules (Fig. 1), gradually filling and occluding them, an effect still visible after acid challenge (Fig. 2). Hill and his research team believe that fluorapatite crystals probably favour growing on the existing apatite-rich surfaces within the dentinal tubules, which have a higher mineral content than elsewhere. As the fluorapatite occludes the dentinal tubules, it reduces the flow of fluid through them, known as hydraulic conductivity, the cause of sensitivity. Owing to the increased stability and resistance of fluorapatite, the tubules remain occluded more completely and the hydraulic conductivity shows a greater percentage reduction, and consequently, BioMinF achieves faster remineralisation rates than other toothpastes tested (Fig. 3).
Importantly, patients appear to like it. According to a BioMinF user survey in the UK on patients who suffered from sensitivity, around 65 per cent of them found that their sensitivity had improved or even resolved, and almost half said BioMinF was more effective than other sensitivity toothpastes, while just under 40 per cent found it roughly similar in effect. Overall 95 per cent reported BioMinF to be good or excellent, liking the texture, flavour, feeling of cleanliness and level of foaming.
Crucially, though, rigorous testing in the state-of-the-art laboratories at Queen Mary has shown that delivering this precise combination of calcium, phosphate and fluoride ions in the slow-release format provided as the glass dissolves forms an apatite mineral in the mouth that is not only quick to start occluding the dentinal tubules effectively, but also continues to work over several hours and is stable and resistant to acid attack. This is great news for sensitivity sufferers.