Steven M. Adair

Randomized Clinical Trial of the Effect of Prenatal Fluoride Supplements in Preventing Dental Caries

This randomized, double-blind study tested the caries-preventive efficacy of prenatal fluoride supplementation in 798 children followed until age 5. Initially, 1,400 women in the first trimester of pregnancy residing in communities served by fluoride-deficient drinking water were randomly assigned to one of two groups. During the last 6 months of pregnancy the treatment group received 1 mg fluoride daily in the form of a tablet and the control group received a placebo. Both treatment and control subjects were encouraged to use postnatal dietary fluoride supplements. Caries was measured in children at age 3 and 5 while fluorosis was assessed at age 5. Caries activity was very low in both study groups: 92% of children remained caries-free in the treatment group and 91% remained caries-free in the placebo group. Fluorosis was observed in 26 subjects, all classified as very mild. Overall, there were no statistically significant differences in the study groups with respect to caries and fluorosis in deciduous teeth. The study had sufficient power to detect an absolute risk reduction of 5.1% while only a 1.5% reduction was observed. These findings do not support the hypothesis that prenatal fluoride has a strong caries-preventive effect.

Plaque fluoride concentrations are dependent on plaque calcium concentrations

Despite the 1,000-fold difference between the fluoride concentrations ([F]) in dentifrices and fluoridated drinking water, clinical and epidemiological studies have shown that they have similar cariostatic effects. This double-blind, crossover study was done to determine whether the [F] in dental plaque is related more to the [F] of the dentifrice used or to the plaque concentrations of calcium and magnesium. The subjects (n = 13) were adults and residents of a city served with fluoridated drinking water. After 1 week of using a fluoridated dentifrice (940 ppm) or a placebo dentifrice, whole saliva and plaque were collected 1.0 h and approximately 12 h after the last use of the dentifrices. The average salivary [F] after brushing with the F dentifrice was higher than after using the placebo. The average plaque [F] 1.0 h after brushing with the F dentifrice was higher than after using the placebo (p < 0.01), but the difference at 12 h was not significant. Plaque [Ca] and [F] were directly related under all experimental conditions (p = 0.0001). The relationships between plaque [Mg] and [F] were weaker and inconsistent. Based on these findings and reports in the literature it is concluded that, for persons whose drinking water is fluoridated, plaque [F] throughout much of the day is not significantly increased by the use of a fluoridated dentifrice. Instead they are directly related to plaque [Ca]. These findings offer at least a partial explanation for why fluoridated dentifrices and drinking water have similar cariostatic effects.

Prevention of dental disease: The role of the pediatrician

Evidence increasingly suggests that to be successful in preventing dental disease, we must begin preventive interventions within the first year of life. Pediatricians are well positioned to begin this process with early assessment of oral health and provision of anticipatory guidance, including ensuring that patients establish a dental home in addition to their medical home. This article provides information that will enable pediatricians to assess caries risk and provide practical and effective advice to parents about preventing dental disease, including oral hygiene, diet, and fluoride recommendations.

Fluoride in whole saliva, parotid ductal saliva and plasma in children

The purpose was to investigate the relation between fluoride concentrations in whole saliva, parotid ductal saliva, and plasma in 5- to 10-year-old children (n = 17). Two stimulated whole-saliva samples were obtained from each child. Before the second sample was obtained, each child rinsed several times with a total of 100 ml of deionized water. Parotid saliva samples were obtained by use of a Lashley cup. Fluoride concentrations were determined by fluoride ion-specific electrode after diffusion with hexamethyldisiloxane. Rinsing with deionized water did not significantly reduce the fluoride concentration in whole saliva. The whole-saliva fluoride concentrations were not significantly related to those in plasma or parotid ductal saliva. Parotid fluoride concentrations, however, were significantly related to plasma fluoride concentrations (p < 0.0001) by a proportionality constant of 0.80. It was concluded that parotid salivary fluoride concentrations can be used to estimate plasma fluoride concentrations in 5- to 10-year-old children.

Effect of Artificial Saliva and Calcium on Fluoride Output of Controlled-Release Devices

The purpose of this in vitro study was to assess the effect of graded concentrations of calcium in artificial saliva on the output of fluoride from HEMA/MMA controlled-release devices. After the initial release rates were determined in deionized water, the devices were assigned to five groups. The devices of one group remained in deionized water throughout the 19-day study while those of the other groups were placed in artificial saliva containing 0, 4.5, 8.0, or 12.0 mg% calcium on days 4-13. Ten devices of each group were placed in deionized water again on days 14-17 and then in 0.1 mol/l HCl on days 18-19. The five devices of each group that were not placed in deoinized water on day 14 were inspected for surface crystals and then placed in 1 mol/l KOH for 2 days. The fluoride release rates in artificial saliva were reduced by 71-90% and in proportion to the calcium concentration. The release rates in deionized water (days 14-17) approached the baseline values; they exceeded baseline rates by 13-49% while in HCl. The fluoride release rates did not differ among the groups while in KOH, but calcium output was directly related to the calcium concentration of the artificial saliva. The results indicate that fluoride release from HEMA/MMA devices is markedly reduced in artificial saliva and that the reduction is proportional to the concentration of calcium.

Fluoride content of school lunches from an optimally fluoridated and a fluoride-deficient community

Abstract This study was conducted to compare contemporary dietary fluoride intake to surveys conducted a decade ago. It also served as a means of evaluating the difference in fluoride intake between residents of an optimally fluoridated and a fluoride-deficient community. Forty-four type A school lunches were collected from an optimally fluoridated ( n = 24) and a fluoride-deficient ( n = 20) community and analyzed for fluoride content. Fluoride analysis was accomplished using a microdiffusion technique to assay the acid-diffusible fluoride fractions. The mean total fluoride content of the lunches from the optimally fluoridated community was 227 μg. This was significantly higher than the mean fluoride content of 54 μg from the lunches in the fluoride-deficient community. The mean fluoride concentrations of the solid food from the optimally fluoridated and the fluoride-deficient communities were 0.53 and 0.23 μg fluoride/g, respectively. This difference was also statistically significant. The differences between the two communities in fluoride content of the lunches may be due to differences in the processing and cooking of the samples, primarily in the use of optimally fluoridated water for preparing some foods. In addition, the fluoride content of the lunches from the optimally fluoridated community was higher than expected on the basis of previous reports from similar communities. This difference may be related to differences in analytical techniques, changes in dietary habits, and an increase of fluoride in the food chain.

Interexaminer Agreement for Readings of Dip Slide Tests for Salivary Mutans Streptococci and Lactobacilli

This study reports the interexaminer agreement of three pairs of evaluators of salivary dip slide tests for mutans streptococci and lactobacilli. 717 Cariescreen SM and Bactotest LB dip slides were available for assessment by 2 dentists and 1 dental hygienist. A single calibration session was held prior to the onset of the study. Each dip slide was read once by each examiner independently. Among the three pairs of examiners, Pearson R values ranged from 0.84 to 0.90 for Cariescreen and from 0.78 to 0.87 for Bactotest. Kappa statistic values ranged from 0.56 to 0.61 for Cariescreen and from 0.70 to 0.74 for Bactotest. The range of agreement was from 72.2 to 76.9% for Cariescreen and from 86.4 to 88.3% for Bactotest. The majority of disagreements were of one category in magnitude, though there were a few disagreements of greater magnitude. This study found moderately strong agreement among the three examiners; it suggests that multiple examiners of dip slide tests carefully calibrated initially and periodically to ensure a high level of agreement.