In a healthy mouth, the gums fit snugly against the tooth enamel, allowing very little access to the root surfaces below. The roots are thus protected from bacterial plaque and potential decay. When the gums recede, due to poor dental care, oral piercings, abrasion of the gums with overly vigorous tooth brushing, or simply age, the root surfaces are exposed. This is an especially dangerous time for your teeth!
The root surface is primarily made out of dentin. Compared to enamel, dentin has significantly less mineral content (chiefly calcium and phosphorus) and is far more porous. While approximately half the root is made out of minerals, the other half is formed from collagen. This fibrous tissue offers little defense against acids, so as dentin is rapidly demineralized by acids from our foods, drinks and oral bacteria, the collagen is destroyed too. This breakdown of minerals and destruction of collagen leads to root caries.
Remineralization of the root surface will occur and some regrowth of dentin is possible. Both are encouraged with the use of fluoride, applied topically by our dentists to the exposure site or with rinses, gels and toothpastes at home. When brushing your teeth, remember to use only soft toothbrushes so you don’t further degrade your gums or exposed roots!
Where remineralization is no longer possible, shallow lesions can be filled, much like caries in the enamel. Deeper cavities in the root may require root canal therapy or even extraction. The best way to avoid this worst-case scenario is to avoid gum recession. If your gums have receded already, modifying your diet to avoid highly acidic substances, like sodas and sweet teas, while practicing regular oral hygiene is essential. Otherwise, we may end up discussing dental implant therapy!