Root Surface Caries
Caries can affect any surface of the teeth. The most commonly seen caries are found on the crown of a tooth, above the cemento-enamel junction, it is also possible for caries to form on the root surface, below the cemento-enamel junction. Dental root caries has received a great deal of attention in the past few decades. A variety of different patients are at risk for root surface caries. Dentists use several methods of treatment.
Root surface caries are also called cemental caries, cervical caries, or radicular caries. (Wilkins) Root surface caries only involves the roots of teeth. The cementum and dentin located just below the crown of the tooth is involved. No involvement of enamel is seen with root surface caries. Bone loss and corresponding gingival recession are the first symptoms to be seen in the caries process. These result in exposed root surfaces, which are more prone to forming caries because caries does not form in the root surface while periodontal fibers are still attached. Clinically, the lesion starts on the root surface. It has been found that root caries spreads in a lateral or circumferential manner, and over time can extend completely around the tooth, undermining the enamel. (Wilkins)
In general, root caries have the same etiology as coronal cavities. S. mutans, Lactobacilli, and sometimes, Actinomyces are involved and are found in high numbers in root caries, but there are two main differences between enamel and root surface caries. (Flaitz) These differences cause the lesion on a root surface to be more destructive than that in enamel. First, because the pH at which demineralization will occur is higher for root cementum (approx. pH 6.0) than for enamel (approx. pH 5.0).(Wilkins) Therefore, root cementum has potential for demineralization at an earlier point in time than enamel does. Secondly, once the cementum is demineralized, the dentin contains dentinal tubules which, if present, are potential methods of entry for the pathogenic microbes as mentioned previously, such as S. mutans, Lactobacilli, and sometimes Actinomyces; whereas, enamel consists of tightly-arranged crystal prisms, which have a much lower chance for bacterial entry. The process of caries formation begins with colonization by acid-producing bacteria plaque. In the next step, Gram-positive bacteria invade the dentinal tubules, which leads to the formation of microcavities, demineralization of the dentinal tubules, and destruction of the organic material. This process is enhanced with the presence of gingival recession.(Hammel)
Clinically, root caries appears as a soft, irregularly shaped lesion, either totally confined to the root surface or also involving the enamel at the cemento-enamel junction. (Flaitz) It is more easily detected on exposed root surfaces. It has been found that 10% to 20% of root caries lesions are found subgingivally, especially at the interproximal region. The most common locations also include exposed roots of...