For centuries, tooth caries or, as they are more commonly known as, cavities have been repaired using a variety of materials, including amalgam, composite and glass ionomer fillings. However, one major flaw that all of the above exhibit is that it does not allow the tooth to naturally develop again such that it can return to its former state – this would not necessarily be a problem as the tooth cannot regenerate dentine or enamel by natural means in most cases through the process of remineralisation. Thus, the main materials used for fillings as well as inlays and onlays had always been used to prevent further inflammations of periapical tissue or infections from forming.
But first, what are caries? Cavities or dental caries are the formation of holes in the dentine of a tooth, the mineral layer formed by odontoblasts, which are specialised mesenchymal stem cells, that is under the enamel. These holes are formed by bacteria, which form a layer of biofilm and produce acid which erodes the tooth’s enamel and dentine. The acid is dependent on the frequency of sugar intake mainly, with the fermentable carbohydrates being digested by the bacteria, among other factors too. It usually neutralised by the alkaline nature of the saliva, however, if the pH falls to below 5.5 as a result of too much acid being produced then the tooth decay can form. In addition, the tooth enamel can be reformed slightly through a process called remineralisation, although this occurs at the same rate as demineralisation of the teeth (from the acid) and so any major changes will result in decay anyways.
New research found that Tideglusib, a drug initially used for treating Alzheimer’s, could also be used in promoting the regeneration of the natural tooth in mice, which could be used to counteract the further development of cavities. Despite the fact that dentine could be reformed naturally, provided the pulp is exposed either through trauma or an infection, the tooth can only can only regrow a thin layer, called a dentine bridge, which would not repair the cavity. Tideglusib works by stimulating the stem cells in the pulp of the tooth with a cavity as well as prevents the GSK-3 enzyme from functioning in the WNT signalling pathway, allowing dentine to form.
Small biodegradable collagen sponges were used to supply low doses of GSK-3 antagonists (short for glycogen synthase kinase) which promotes the formation of dentine. This would be significant as the carrier sponge would degrade over time and thus resulting in the newly formed dentine completely filling in the carious lesion by natural means. Not only this but it would evade the need to design the new dentine as being tooth coloured as well as potentially leading to future developments in dentalcare.
However, from a pragmatic point of view, given the reluctancy of the NHS for the use of composite fillings due to its cost relative to the cheaper alternative, amalgam fillings, such a drug may not be used readily for the foreseeable future. Despite this, the drug could lead to vast improvements in the quality of dentalcare as well as the quality of dental health in the UK.
Photo Credits due to: https://pxhere.com/en/photo/1437883