Johanna Ganter1,2, Elmar Hellwig3, Sam Doerken4, Ali Al-Ahmad3. 1. Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany. johanna.ganter@uniklinik-freiburg.de. 2. Department of Orthodontics, Center for Dental Medicine, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany. johanna.ganter@uniklinik-freiburg.de. 3. Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany. 4. Institute of Medical Biometry and Statistics, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany.
Abstract
OBJECTIVES: The aim of the present study was to evaluate the growth and acid synthesis of cariogenic pathogens in vitro when rebaudioside A was the sole source of carbon, compared to sucrose, xylitol, and a commercial sweetener containing rebaudioside A. MATERIALS AND METHODS: First, sucrose or sugar substitutes were added to human saliva and the pH was measured over 10 h. Subsequently, the growth and acid synthesis efficiency of Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Lactobacillus rhamnosus, Lactobacillus paracasei, and Candida albicans were investigated: after adding them to minimal culture media containing only one of the carbon sources, the optical density and pH were determined over 10 h. RESULTS: A significant pH drop only occurred in the sucrose group of human saliva whereas no differences were found between the sugar substitute groups. The individual strains of caries pathogens showed significantly lower growth rates and less acid synthesis in the sugar replacement groups, in comparison to sucrose. However, these groups also showed bacterial growth and a decline in pH. CONCLUSION: Xylitol appeared to be superior to rebaudioside A regarding the inhibition of mutans streptococci. The results for the remaining microorganisms indicate that rebaudioside A causes a similar or lower acid synthesis than xylitol. As saliva contains buffer systems, the metabolism of rebaudioside A did not seem to shift the equilibrium to demineralization. CLINICAL RELEVANCE: Rebaudioside A may not be suitable as a targeted Streptococcus mutans treatment, but it could contribute to a reduction of caries risk as a replacement for sucrose.
OBJECTIVES: The aim of the present study was to evaluate the growth and acid synthesis of cariogenic pathogens in vitro when rebaudioside A was the sole source of carbon, compared to sucrose, xylitol, and a commercial sweetener containing rebaudioside A. MATERIALS AND METHODS: First, sucrose or sugar substitutes were added to human saliva and the pH was measured over 10 h. Subsequently, the growth and acid synthesis efficiency of Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Lactobacillus rhamnosus, Lactobacillus paracasei, and Candida albicans were investigated: after adding them to minimal culture media containing only one of the carbon sources, the optical density and pH were determined over 10 h. RESULTS: A significant pH drop only occurred in the sucrose group of human saliva whereas no differences were found between the sugar substitute groups. The individual strains of caries pathogens showed significantly lower growth rates and less acid synthesis in the sugar replacement groups, in comparison to sucrose. However, these groups also showed bacterial growth and a decline in pH. CONCLUSION:Xylitol appeared to be superior to rebaudioside A regarding the inhibition of mutans streptococci. The results for the remaining microorganisms indicate that rebaudioside A causes a similar or lower acid synthesis than xylitol. As saliva contains buffer systems, the metabolism of rebaudioside A did not seem to shift the equilibrium to demineralization. CLINICAL RELEVANCE: Rebaudioside A may not be suitable as a targeted Streptococcus mutans treatment, but it could contribute to a reduction of caries risk as a replacement for sucrose.