Dental Fluorapatite Formation with Glass-Based Toothpaste

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The effect of lifestyle choices on the quality of teeth is well documented. Regular smoking or coffee drinking can cause teeth to develop yellow stains, eating sugary foods leads to a build-up of bacteria that causes bad breath and dental caries, and eating lots of acidic foods can weaken enamel.

Furthermore, receding gum lines and weakened enamel can expose nerve endings causing sensitive teeth which experience pain on contact with food and drink – particularly very cold or very hot ones.

The most common approach to protect teeth is regular brushing with toothpaste of good quality. Currently, there seems to be a toothpaste designed to resolve any possible dental health concern, with specialist toothpastes marketed for smokers, tooth whitening, sensitive teeth, and gum health. Several toothpastes offer all-round protection and contain whitening ingredients to restore natural tooth color, anti-bacterial and tartar control agents to reduce the accumulation of plaque and prevent gum disease, and fluoride to strengthen teeth. The worldwide market for toothpaste is presently worth roughly £1.5 billion.

Although an extensive range of toothpastes are available, there has been little change to the formulation since the inclusion of fluoride more than 40 years ago. However, a novel technology has now been introduced to the toothpaste market— bioactive glass.

Bioactive glass toothpaste has already been shown to decelerate tooth decay and reduce tooth sensitivity by accelerating the repairing of enamel.

What Causes Tooth Decay?

Tooth decay occurs when sugars in the food and drinks consumed are metabolized by bacteria to produce acids, which dissolve the protective enamel coating of a tooth and subsequently expose the dentine below.

While the incidence of forming dental caries has reduced appreciably by the addition of fluoride to toothpaste, corrective action for tooth decay still accounts for most of the dentist visits. Indeed, in the US, 21% of children aged 6 to 11 years and 92% of adults aged 20 to 64 years have had dental caries in their permanent teeth1.

In order to minimize the risk of formation of dental caries, toothpastes contain antibacterial agents to prevent the build-up of teeth-eroding bacteria, and fluoride which makes the surface of teeth more resistant to acid and decay.

What Causes Tooth Sensitivity?

The soft dentin within the tooth contains microscopic tubules. These are filled with tiny nerve endings, which are protected by a hard outer layer of enamel. Aggressive teeth brushing and aging can result in a receding gum line or weaken the protective enamel coating — exposing nerve endings within the dentine. As a result, consuming cold, hot, sticky, or acidic foods becomes extremely painful. In the United States alone, about 40 million adults undergo tooth sensitivity.

To provide momentary relief for sufferers of sensitive teeth, toothpastes containing ingredients that numb a tooth's nerve-endings are now available.

Bioactive Glass in Dentistry

Bioactive glass is a type of crushed glass that is capable of bonding to hard as well as soft tissue. It is biocompatible and exhibits antimicrobial activity. It is available in an array of formulations of varying sizes and with specific compositions that can be customized to fulfill a specific requirement2,3.

After the success of bioactive glass in various biomedical applications4, its potential in dentistry was examined. Bioactive glass has been shown to increase the durability of composite fillings and to accelerate healing after the repair of periodontal defects4. Addition of bioactive glass to composite dental filling material reduced the incidence of secondary tooth decay at restoration margins7, enhanced the mechanical properties of a filling6, and encouraged remineralization of dental caries5.

The ability of bioactive glass to improve mineral formation in the dentin when included in a tooth filling raised the prospect of it repairing damage to the enamel before it advances to dental caries.

Bioactive Glass Toothpaste

Scientists at Queen Mary University of London have developed a dissolving form of bioactive glass for addition in toothpaste8. The bioactive glass releases fluoride, phosphate, and calcium ions over 8-10 hours, which is nearly the time between morning and evening teeth brushings. The released ions form a protective fluorapatite layer by reacting with saliva in the mouth.

Fluorapatite is considerably more resistant to the acids produced by bacteria than the hydroxyapatite formed with bioactive glasses used in tissue engineering. It also promotes remineralization. The protective layer of fluorapatite on teeth creates a barrier that dissuades the formation of dental caries. Bioactive glass toothpaste will be of especially advantageous to elderly people in whom the protective effects of fluoride are diminished.

In addition, the released minerals aid in occluding the exposed dentinal tubules, thus preventing the pain of tooth sensitivity. Unlike traditional toothpastes for sensitive teeth, which merely mask the pain of sensitive teeth, bioactive glass toothpaste stops the pain itself. It accomplishes this by promoting remineralization, which fills the dentin tubules in the enamel minimizing the introduction of hot or cold sensations to nerve endings. Likewise, bioactive glass toothpastes have been shown to repair the damage caused to enamel by bleaching9.

Moreover, bioactive glass toothpaste can be produced using chlorine in the place of fluorine. This provides an alternative means of tooth protection for people who are unable to use fluoride toothpastes.

This toothpaste is unique because it can put back the mineral lost from your teeth after consumption of an acidic drink, but without the use of fluoride. This isn't just for people who have bad teeth, everyone can potentially benefit from using this new toothpaste.

Professor Robert Hill, Queen Mary University of London Institute of Dentistry

References

  1. National Institutes of Health. NIDCR Data & Statistics. Dental Caries (Tooth Decay) in Adults (Age 20 to 64). Available at: https://www.nidcr.nih.gov/DataStatistics/FindDataByTopic/DentalCaries/DentalCariesAdults20to64.htm
  2. Brauer DS. Bioactive Glasses—Structure and Properties. Angew Chem Int Ed 2015;54: 4160–4181.
  3. Mo Sci Corporation website. http://www.mo-sci.com/en/products
  4. Rahaman MN, et al. Bioactive glass in tissue engineering. Acta Biomaterialia 2011;7:2355 2373.
  5. Prabhakar AR, et al Comparative Evaluation of the Remineralizing Effects and Surface Micro hardness of Glass Ionomer Cements Containing Bioactive Glass (S53P4):An in vitro Study. Int J Clin Pediatr Dent. 2010 May-Aug;3(2):69-77. doi: 10.5005/jp-journals-10005-1057. Available at https://www.ncbi.nlm.nih.gov/pubmed/27507915.
  6. Chatzistavrou X, et al. Fabrication and characterization of bioactive and antibacterial composites for dental applications. Acta Biomater. 2014;10:3723–3732. Available at https://www.ncbi.nlm.nih.gov/pubmed/24050766
  7. Khvostenko D, et al. Bioactive glass fillers reduce bacterial penetration into marginal gaps for composite restorations. Dental materials 2016;32(1):73–81. Available at http://www.demajournal.com/article/S0109-5641(15)00437-6/pdf
  8. Swansbury LA, et al. Modeling the Onset of Phase Separation in CaO–SiO2–CaCl2 Chlorine-Containing Silicate Glasses. The Journal of Physical Chemistry B 2017; 121(22):5647. Available at http://pubs.acs.org/doi/10.1021/acs.jpcb.7b02986
  9. Gjorgievska E and Nicholson JW. Prevention of enamel demineralization after tooth bleaching by bioactive glass incorporated into toothpaste. Australian Dental Journal 2011; 56: 193–200.

Mo-Sci Corp

This information has been sourced, reviewed and adapted from materials provided by Mo-Sci Corp.

For more information on this source, please visit Mo-Sci Corp.

Last updated: Mar 20, 2018 at 1:20 PM

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