2022 Top Story in Clinical Dentistry: Topical Fluoride Effectiveness in Adults at High Risk for Caries

The use of fluoride to prevent tooth decay has involved more than 100 years of research, yet many unanswered questions remain regarding the best practices. We know that dental caries continues to be prevalent and an economic burden and that it adversely impacts quality of life.^1,2 We also know that fluoride in various forms has shown benefits in reducing the risk and slowing the progression of caries, yet research has tended to focus more on children than on high-risk adults.³ We selected the publication by Jurasic et al as our Top Story of 2022 because it focuses on how fluoride in various forms and doses impacts caries-related treatments in high-risk adults.³ The study addresses an area of increasing importance, as more seniors are living longer, retaining more of their dentition, and have more comorbidities that collectively increase their risk for dental caries.⁴

This retrospective study included an analysis of over 68,000 predominately male veterans at high risk for dental caries who were identified as having had at least two carious lesions treated in the “index” year and did not receive fluoride interventions or caries-related restorative treatment in the year prior. During the “index” year, veterans received either in-office treatment with 5% sodium fluoride (NaF) varnish, 2% gel, 2% rinse, or 1.23% acidulated phosphate fluoride (APF) gel, at-home applications of 1.1% NaF toothpaste, or no fluoride at all. New caries-related restorations or extractions were recorded in the year following the “index” year. The confounding variables controlled for included anticholinergic medications that could contribute to hyposalivation, the frequency of dental prophylaxis appointments, age, sex, ethnicity, and medical comorbidities.

Some clinically significant findings

The most impactful forms and doses of fluoride for this population were 5% NaF varnish (22,600 ppm of fluoride) or 1.23% APF gel (9050 ppm of fluoride) professionally applied twice a year, resulting in 29% decreased odds of a veteran needing caries-related treatment during the observation period. This highlights the importance of scheduled in-office maintenance visits in adult patients at high risk for dental caries.

One of the more interesting findings was that 1.1% NaF toothpaste (5000 ppm of fluoride) was not effective in decreasing the risk of new carious lesions in this population. These results differ from those reported by other investigators, who found a protocol of 1.1% NaF toothpaste and 0.12% chlorhexidine gluconate rinse to be effective in preventing decay.^5,6 In Jurasic’s study, the veterans may not have used therapeutic amounts of toothpaste or did not include chlorhexidine rinses to help mitigate the bacterial challenge.

Of course, we should not forget other effective strategies to manage caries in high-risk adults, including but not limited to silver diamine fluoride,⁷ fluoridated water, dietary compliance, and automated text reminders. Compliance is critical; if it is lacking in an adult or senior patient, relying on at-home protocols alone may be problematic. In-office maintenance visits with the application of 5% NaF varnish or 1.23% APF gel may, therefore, be one of the many keys to mitigating caries risk in high-risk adult populations.