Tag: tooth decay

benefits of water fluoridation

Water fluoridation programs re-emerge as a controversial topic from time to time. Just last year it was a hotly debated topic in Portland, Oregon.  Compound Interest covers the benefits of water (and other) fluoridation programs:

The enamel that coats your teeth is made up primarily of the compound hydroxyapatite. This ionic compound consists of calcium ions, phosphate ions and hydroxide ions, and is also a major component of your bones. Enamel is well known for being pretty strong, but it can be slowly broken down and lose ions from its structure under acidic conditions. This is known as demineralisation. Our body has a built-in countermeasure for this, and can replace the ions lost with ions from our saliva, in a process known as remineralisation. However, sometimes the rate at which this replacement occurs is below that at which the ions are being lost. When this happens the pores in the tooth can become enlarged, and cavities and tooth decay can result.

Fluoride ions can help arrest this process. They can be incorporated into the hydroxyapatite structure, replacing the hydroxide ions and forming fluorapatite. Fluorapatite is stronger than hydroxyapatite, and is also more resistant to acidic conditions. This means it can greatly delay the onset of cavities and tooth decay, and this is the reason why there’s a clamour to add it to water supplies.

Much more at his blog, including a nice infographic.

cavemen had fewer cavities

The teeth of this Egyptian skull are healthier than the teeth of most people living today.

Science magazine reports on pre-historic dental hygiene. Compared to modern mouths, the mouth’s of cavemen seem to have been colonized by fewer bacteria that cause tooth decay. The switch to agriculture and a diet that includes lots of sugars and refined carbohydrated seem to correspond to a surge in these types of bacterial species:

With these data, they charted the spectrum of bacterial species within the human mouth over the past 7500 years. Hunter-gatherers had fewer species that cause cavities and periodontal disease, and different percentages of all 15 phyla of bacteria found in modern teeth, plus some unclassified bacteria. Early farmers showed a sharp increase in bacteria that cause tooth decay, such as a Veillonellaceae strain, and a dramatic surge inPorphyromonas gingivalis, which causes periodontal disease.

The first significant sample of S. mutans turned up around 4300 years ago in the Bronze Age in Yorkshire, U.K. Overall bacterial diversity, including higher levels of S. mutans and P. gingivalis, seemed to stabilize through the Bronze Age and medieval period. Then, sometime in the past 400 years, the diversity of bacteria within each tooth dropped sharply once again. Modern samples and preliminary data from the mid-19th century show an oral environment even more dominated by S. mutans. Cooper concludes that the change occurred with the Industrial Revolution, about 1850 in England, when cavities also increased and refined sugars entered the diet. “Sugar and flour caused everything to go berserk,” he says.

More here and here.

graphene is a wondrous material

Everyday it seems there is a new use for graphene. Today’s uses is in tooth tattooing to prevent bacterial accumulation and tooth decay:

The sensor is made of graphene and can detect bacteria in our mouths to the single-cell level, according to researchers at Princeton and Tufts universities. Michael McAlpine and colleagues developed a method to print graphene nanosensors onto a silk substrate. They added electrodes and an inductive coil to power the device, which can then be transferred onto teeth or other biological materials.

The graphene is then doped with naturally occurring antimicrobial peptides, which bind to bacteria and can be used as a bug detection system. The result is a battery-free, wireless sensing device that can pinpoint exactly which type of bacteria is present in a person’s mouth. Because it’s imprinted onto silk, the detector has elastic properties, so it could also be integrated onto soft tissues, too, not just tooth enamel. To test it, McAlpine and colleagues grafted it onto a raw chicken breast.

More studies are still needed to see how long the antibacterial properties might last in a person’s mouth, especially for people who brush their teeth regularly. Hospitals are also hoping it can help in warding off multi-drug resistant bacteria.

Read the study in Nature Communications here. Abstract available for non-subscribers.

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