Cariogenicity potential of a low-pH sugar-free drink

Abstract

BACKGROUND: Dental caries is the most common chronic disease globally and among U.S. children. Numerous previous studies have shown that, as compared to other U.S. communities, children in Alaska Native communities are at the highest risk of developing dental caries. In recent years, there have been many efforts to develop community-based interventions to address behaviors driving the tooth decay epidemic in rural Alaska Native communities. According to Anecdotal evidence from health providers and parents in these communities, a reduction of carbohydrate intake—particularly, added sugars from sugar-sweetened beverages (SSBs) that strongly correlate with high caries risk and poor health —is an important intervention target in children. In community-based behavioral intervention aimed at helping children to reduce their added sugar intake, Chi and co-authors offered Alaska Native children of Yup’ik descent sugar-free drinks of the same flavors as the corresponding sugared versions. However, it is uncertain whether this approach would prevent dental caries among Alaska Native children. AIMS: The objective of this study was to evaluate the cariogenicity potential of sugar-free Tang as compared to the traditional sugared Tang. The second goal was to evaluate the caries preventive effects of fluoride exposure when consuming sugar-free and sugared Tang. Tang was the chosen drink as it is the most popular sugared artificially fruit-flavored drink in Alaska Native communities. METHODS: An in vitro microbial caries model was used. Sixty-four human tooth samples (3 x 3 mm) were divided into four groups, n=16. The 16 specimens in each treatment group were divided into two vessels, with eight specimens in each. The specimens were then glued to a plastic slab affixed to the cap of a 50-ml polypropylene tube and sterilized with ethylene oxide gas. Samples were incubated at 37°C in a Streptococcus mutans (TH16) caries model for 5 days. During the first 2 days of incubation, the samples were exposed to the feeding solution THBS 1%. Subsequently, Tang exposure (3x/day for 1 min each time) and toothpaste slurry treatments (2x/day for 2 min each time) started and lasted for 3 days. At the end of the experiment, biofilm was disrupted from samples and the CFU/tooth was calculated. Cross-Sectional Microhardness (CSMH) was done to calculate average lesion volume % mineral for each group. The resulting enamel lesions of each tooth sample were analyzed by confocal laser scanning microscopy (CLSM) and measured to determine average total lesion depth and surface loss for each experimental group. Data were analyzed using ANOVA and pairwise multiple group comparisons were calculated using the Student-Newman-Keuls method. RESULTS: sugared Tang group exhibited significantly higher viable bacterial counts than the other three groups (p< 0.05). Demineralization data (mineral loss and area under the curve) showed a significant difference between the sugared Tang group treated with fluoride toothpaste and both sugar-free Tang groups (p<0.05). However, no significant difference was found between both sugar-free Tang groups (with and without exposure to F toothpaste). With regard to the lesion depth among the four groups, sugared Tang and sugared Tang treated with fluoride toothpaste groups exhibited the deepest lesions; however, the differences did not reach statistical significance (p>0.05). Surface loss results suggest that sugared Tang group experienced the highest surface loss as compared to the other three groups (p< 0.05). When fluoride treatments were added, the sugared tang groups had significantly less surface loss, but comparable lesion depth. whereas the sugar free group had no significant difference. CONCLUSIONS: Under the laboratory conditions of this study sugar-free Tang is less cariogenic than its sugared counterpart. Fluoride treatments effectiv