A day spent guzzling coffee and sodas, eating, and washing it all down with a glass of red wine in the evening really takes a toll on our teeth, and even the act of brushing them contributes to their continual decline.
Both mechanical abrasion and the acids in our diets continually wear away at our teeth’s protective enamel coating, eventually exposing the porous dentin layer below. This, in turn, leads to pain and temperature-related sensitivity because the nerve ending-studded pulp tissue is on the other end of the dentin tunnels.
And unfortunately, it seems that the specialty products that claim to either prevent further erosion and reduce sensitivity from existing enamel surface loss don’t actually work. According to a study in Scientific Reports, eight new and popular anti-erosion or desensitizing toothpastes caused more enamel loss than brushing with no toothpaste at all.
The findings are in line with previous research that has also revealed none of the available toothpastes seem to protect against surface loss, although many are effective at reducing the bacteria that cause cavities.
In the current investigation, a team of Brazilian and Swiss dental scientists recreated the daily conditions of our beleaguered teeth using 150 enamel specimens prepared from donated, healthy premolars. Each specimen was exposed to a 5-day “erosion-abrasion” cycle: Once per day, the enamel sample was soaked in a diluted citric acid bath (pH 3.6) for 3 minutes, then rinsed with water and air dried.
Next, the specimen was brushed with an automated brushing machine for 25 seconds using either a slurry of one of the eight toothpastes evaluated and artificial saliva (AS), AS with the control toothpaste (Colgate Caries Protection), or AS alone.
Throughout the experiment, all teeth showed largely similar signs of progressive surface loss (SL).
Of the desensitizing pastes, Sensodyne Repair and Protect induced the least SL (and was the only formulation tested that beat the control toothpaste), and Blend-a-Med was the worst. Among the anti-erosion toothpastes, Elmex Erosion Protection was the least abrasive and Regenerate was the worst.
An ingredient-by-ingredient analysis suggested that the presence of tin and higher concentrations of calcium and phosphate is associated with decreased abrasion, however, since the differences in SL between toothpastes were very slight, the authors caution that more studies are needed to confirm the links.
Until we know for sure which brands are best, the researchers advise that people with sensitivity should simply limit consumption of acidic foods and beverages and try to use gentle toothbrushing techniques.
"We're now working on other studies relating to dentin in order to think about possibilities, given that none of these toothpastes was found capable of preventing dental erosion or dentin hypersensitivity, which is a cause of concern,” said co-author Professor Ana Cecília Corrêa Aranha in a statement.