Evaluation of cariogenicity of isomaltulose in an artifical mouth model

Abstract

OBJECTIVES: To evaluate the cariogenicity of isomaltulose on human tooth infected with multi-species biofilm in an artificial mouth model. METHODS: Human tooth blocks (n=48) each with a 1.0x1.0mm window on enamel and another window on dentine were prepared by applying acid resistant nail varnish on other surfaces. Mixed suspension of Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus and Lactobacillus rhamnosus was adjusted to cell density of 109 CFU/mL and incubated on the blocks in a 6-well plate anaerobically for 2 days. Thereafter, resin plates with tooth blocks were transferred to an artificial mouth model and randomly allocated to three plaque stations. Under computer control, defined medium mucin was continuously supplied at 3.6 mL/hour to simulate saliva flow in human mouth. The three plaque stations were supplied with 5%(w/v) isomaltulose, 5%(w/v) sucrose, or distilled water (control). In a 24-hour cycle, test solution according to the station assignment was supplied 5 times, 5 minutes each time, in 16 hours with an 8-hour break to mimic daily dietary and rest habit. Depth of artificial caries lesions created after 14 days was assessed by micro-CT scanning. RESULTS: Artificial caries lesions in enamel were found in all tooth blocks in the sucrose group with a mean depth of 118.5 µm, but only in 4 of 16 blocks in the isomaltulose group with a mean depth of 35.2µm (p<0.01). The mean depth of lesions in dentine in the isomaltulose group was 98.8 µm, which was not significantly different from that of the distilled water control, 80.6 µm (p>0.05), but significantly smaller than that of the sucrose group, 203.3µm (p<0.001). CONCLUSIONS: This in-vitro study shows the cariogenicity of isomaltulose on human tooth is similar to that of non-sugar control and considerably less than that of sucrose. It has good potential for dental caries prevention by substituting sucrose.