Natural Sweetness of Fruits May Lead to Cariogenic Oral Biofilm: An in vitro Study

Abstract

Background and Objective: Fruits are rich in essential vitamins and minerals and develop protection against many common ailments when taken adequately. The continuous presence of sugars in the mouth causes a microbial imbalance in the oral ecosystem and may lead to dental caries and gum disease if oral hygiene is compromised. This study aimed to determine whether regular consumption of mango, banana and pineapple juices have any effect on oral biofilm and to associate their sweetness properties to cariogenic potential. Materials and Methods: Mixed-bacterial suspension consisting of Streptococcus mutans, Streptococcus sanguinis and Streptococcus mitis was used to form early biofilm models of 3 h and established at 24 h. The biofilms were exposed to doses of fruit juices at three intervals to mimic three daily intakes. The treated biofilms were collected and determined for biofilm mass. The cariogenic potential was calculated with reference to sucrose. The sweetness properties of juices were evaluated based on Brix index, thin layer chromatography profile and reactions to Benedict’s test. Results: The treated biofilms showed an increase in biofilm mass of approximately 11.3-, 5.7- and 4.6-fold for pineapple, banana and mango, respectively. The cariogenic potential of pineapple was almost equal to sucrose, followed by banana and mango. Brix index indicated mango and banana as the sweetest in the form of fruit chunks compared to pineapple. Whereas, in the form of fruit juices, banana exhibited the highest value of sweetness followed by mango and pineapple. Pineapple juice (pH 3.82) was the most acidic, while mango and banana were weak acids (pH 4.35 and 4.42). Reducing sugar glucose was higher in mango and pineapple than that of banana. All three juices have a high content of disaccharide sucrose. Conclusion: Banana, mango and pineapple juices have a high content of sucrose and glucose and are categorized as high sugar-containing fruits. All fruits have high cariogenic potential especially pineapple that is almost equal to sucrose.