Description: Caries ranks alongside gingivitis and periodontitis as one of the most common oral diseases. Treatment of these diseases and their sequela constitutes the bulk of the practice of dentistry. Caries is the only disease that attacks that portion of the tooth exposed to the oral environment. Typical caries are most commonly located in the occlusal pits and fissures of molars and premolars, as well as beneath the contact points on the interproximal surfaces. Special consideration should be given to two types of caries namely radiation caries and nursing bottle caries. Radiation type caries characteristically occur as multiple lesions in the cervical region of the teeth immediately adjacent to the gingiva. These may completely encircle the tooth causing amputation at the gingiva (Fig. 41). Nursing bottle caries are multiple rampant lesions that occur in deciduous teeth of nursing infants and small children (Fig. 42).
Etiology: Caries is caused by the decalcification of the tooth enamel and destruction of the protein matrix. Acid produced by bacteria, mainly Streptococcus mutans, in dental plaque is the recipitating factor. After the enamel is destroyed bacteri a enter the dentin and may extend to the pulp of the tooth. Radiation or cervical caries are usually related to xerostomia and/or chemical changes in saliva. Radiation therapy to the head and neck region usually exceeding 4000 rads.is the most common cause. However, many common medications and systemic chemotherapy may also cause dry mouth and radiation type caries. Nursing bottle caries are due to frequent nursing with solutions containing high concentrations of sugar such as milk, soft drinks, and juices. These solutions allow bacteria to break down the sugars to produce excessive acid thus lowering the pH of both plaque and saliva.
Treatment: Prevention is the best treatment. Most caries can be prevented by daily brushing and flossing to remove plaque. A well-balanced diet without excessive sugars is also beneficial. Topical and systemic fluoride are highly effective in reducing caries, especially if given during the formative years of the teeth. Fluorides have significantly reduced the incidence of caries in the United States in the last several decades. Radiation type caries can also be prevented by a daily regime of topical fluoride. Fluoride treatments either brushed on or applied with a custom mouth guard should begin as soon as radiation or chemotherapy is started or if xerostomia is discovered. Patients who have received head and neck radiation should continue daily treatments for life to prevent possible osteoradionecrosis.
Once caries have developed, dental restorative procedures are the only treatment, although there is now evidence that very early lesions, under intact surface enamel (white spots), may be remineralized. Topical flouride enhances this process.
Prognosis: Prognosis is good if the disease is treated early. If ignored caries is a major cause of tooth loss, and a potential source of both local and systemic infections.
Differential diagnosis: None