Early Caries: No Excavation, Rapid Repair

For years, dental professionals have treated dental caries by removing the affected portion of a tooth and filling the remaining hole with a metal alloy or a resin. While this method is effective for advanced caries, it isn’t ideal for early lesions because an unnecessary amount of healthy tooth structure has to be removed for the alloy or resin to stick.

But with the advancement of a new treatment, this process could go by the wayside. As explained in the February 24 issue of Nature, a new paste made of synthetic enamel has been shown to quickly and efficiently repair early caries without wasting natural tooth enamel.

Early caries results from acid-forming bacteria that cause microscopic damage to the tooth enamel. This layer of enamel measures one to two millimeters in thickness, while early caries lesions often measure only 50 micrometers in depth. Traditional restorative materials, which have a different chemical composition and crystal structure than the natural surface, do not adhere to lesions of such small depth.

The new paste of modified hydroxyapatite is structurally and chemically similar to natural enamel and, therefore, bonds quickly to the surrounding areas through nanocrystalline growth. Japanese scientists applied the first test of this paste to an early lesion in a lower premolar tooth. Within 15 minutes of the application, the lesion had been sealed off, with no evidence of a structural gap between the regrown layer and the original enamel.

Upon examination of the area at the atomic level, the scientists discovered that the crystals in the regrown layer oriented themselves parallel to the surface of the tooth. This new layer had a higher durability and acid tolerance than natural enamel. In addition to showing that the synthetic paste can reconstruct tooth enamel without the excavation process previously required, the scientists also found that the paste may help prevent the recurrence of caries by strengthening the natural enamel.

-Nick Olsen-