Cariogenicity of Commercial Juices in an Experimental Biofilm-Caries Model

Objectives: Despite the widely accepted role of sugar in caries causation, the cariogenic potential of the different presentations of the highly consumed commercial juices is less known. Moreover, caries-inducing potential of the so-called “light juices” has not been explored. The aim was, therefore, to evaluate the cariogenic potential of commercial non-carbonated juices on enamel and dentine.
Methods: A biofilm-based caries model with Streptococcus mutans (S. mutans) was used to test orange-flavored powder, fresh and concentrate juices and their “light” version on bovine enamel and dentin slabs. Mature biofilms of S. mutans were challenged 3 times per day to 5 minutes immersion in commercial orange-flavored juices. A 10% sucrose and 0.9% NaCl solutions were used as caries-positive and negative control, respectively. After 5 days in enamel and 4 in dentin, biofilms were retrieved and analyzed for biomass and polysaccharide formation. Demineralization was estimated from surface microhardness of the tooth slabs, before and after the experimental phase. Differences among groups were considered significant if p<0.05.
Results: Powder, fresh and concentrate juices induced very high demineralization both on enamel and dentin, similar to the 10% sucrose control (p>0.05). Only “light” powder showed lower demineralization than the regular version of the products (p<0.05), but only on enamel. No significant differences were detected on dentin demineralization with any of the tested products. All “light” products induced slightly lower biomass than regular juices. No differences were observed for polysaccharide formation across the samples (p>0.05).
Conclusions: Regardless of their commercial presentation all processed fruit juices appear to be highly cariogenic on enamel and even more on dentin. Juices labeled as “light” are almost as cariogenic as their regular versions. Caries control programs should include counseling on the caries-inducing potential of all commercial juices.