Saliva is the primary component for caries protection and neutralizes acids formed by plaque bacteria. In addition, saliva contributes the needed calcium and phosphate for preventing demineralization and allowing remineralization to occur. Many patients are compromised by reduced salivary flow or saliva with reduced buffer capacity.8 Although many systemic diseases can cause hyposalivation or even xerostomia, the major cause comes from prescription and over-the-counter medications. More than 400 medications are known to have this impact on salivary flow. Many of our patients take these medications daily for the treatment of chronic conditions like hypertension and depression. Others may use them seasonally for allergies. The real clinical significance here is that the balance between remineralization and demineralization processes is most likely disrupted and patients taking these medications are at risk for net demineralization. These patients need to be clearly recognized. In addition to fluoride toothpastes, additional preventive measures and diet counseling for caries prevention should be provided.
Overdentures present a concern from a caries perspective. Plaque is retained more easily on the tooth surfaces with an overdenture residing over these surfaces. These areas are also less accessible to saliva and the protective effects of the oral cavity. A study that followed 296 subjects with overdentures over a period of 20 years found “that regular oral hygiene and regular dental care contribute to lower caries incidence in overdenture patients."9
One additional area of concern requiring focused fluoride therapy is oncology patients who receive radiation therapy to the head and neck. Due to the impact of these treatments on salivary flow rates, rampant caries is often a significant issue. Once again, the ongoing need for fluoride therapies is clear.