Cariogenicity of sucrose substitutes in microtiter and artifical mouth models

Abstract

OBJECTIVES: To evaluate the cariogenicity of three potential sucrose substitutes on human tooth infected with multi-species biofilm in microtitier and artificial mouth models. METHODS: In the microtitier model, 60 human tooth blocks were randomly allocated into 3 groups and placed in BHI medium containing 5% D-tagatose, 1% stevioside or 1% sucralose. Initial pH was adjusted to 7.0. Four common cariogenic bacteria - Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus and Lactobacillus rhamnosus were added to the medium to allow biofilm formation and creation of caries-like lesions in the tooth blocks. These were incubated anaerobically at 37°C for 7 days. After every 24 hours, pH of the medium was measured and the medium was refreshed. In the artificial mouth model, 48 tooth blocks were randomly allocated to three stations. Under computer control, DMM was continuously supplied at 3.6 mL/hour to simulate saliva secretion. The three stations were supplied with 5% D-tagatose, 1% stevioside or 1% sucralose for 14 days. In a 24-hour cycle, test solution was supplied 5 times in 16 hours at 3.6 mL/hour for 5 minutes each, followed by an 8-hour break. Lesion depth was assessed by micro-CT scanning. RESULTS: In the microtiter biofilm growth model, the mean 24-hour pH of tagatose medium was 3.61±0.07 which was significantly lower than those of stevioside and sucralose, 4.81±0.11 and 4.68±0.13 respectively (p<0.001). The mean lesion depth in dentine in D-tagatose group was 405.6±71.8µm which was much greater than those of the stevioside and sucralose groups, 64.4±46.9µm and 72.3±60.7µm respectively. In the artificial mouth model, the mean lesion depth in dentine in the D-tagatose group was 201.4±67.8µm, which was significantly greater than those of the stevioside and sucralose groups, 57.3±40.1µm and 41.6±45.2µm respectively (p<0.001). CONCLUSIONS: Stevioside and sucralose have a lower cariogenicity potential than D-tagatose and are probably better choices as a sucrose substitute.