Oral microbiome has significant impact on both oral and general health. Polyols have been promoted as sugar substitutes in prevention of oral diseases. We aimed to reveal the effect of candies containing erythritol, xylitol or control (sorbitol) on salivary microbiome. Ninety children (11.3 ± 0.6 years) consumed candies during 3 years. Microbial communities were profiled using Illumina HiSeq 2000 sequencing and real-time PCR. The dominant phyla in saliva were Firmicutes (39.1%), Proteobacteria (26.1%), Bacteroidetes (14.7%), Actinobacteria (12%) and Fusobacteria (6%). The microbiome of erythritol group significantly differed from that of the other groups. Both erythritol and xylitol reduced the number of observed bacterial phylotypes in comparison to the control group. The relative abundance of the genera Veillonella, Streptococcus and Fusobacterium were higher while that of Bergeyella lower after erythritol intervention when comparing with control. The lowest prevalence of caries-related mutans streptococci corresponded with the lowest clinical caries markers in the erythritol group. Daily consumption of erythritol, xylitol or control candies has a specific influence on the salivary microbiome composition in schoolchildren. Erythritol is associated with the lowest prevalence of caries-related mutans streptococci and the lowest levels of clinical caries experience. ClinicalTrials.gov Identifier NCT01062633.

This study aims to assess the caries experience among first- and second-grade children in the elementary schools of southeastern Estonia. A representative sample of 485 children was studied. The mean age of children in the first grade was 7.8 years (SD = 0.35) and in the second grade 8.8 years (0.38). The clinical examinations using ICDAS criteria were completed by four calibrated examiners. The inter- and intra-examiner consistency of the examiners was high (surface and tooth-based kappa >0.9). The mean caries experience of dentinal caries lesions was 0.8 (D 4-6 MFT) and 1.6 (D 4-6 MFS) among the first graders and 1.1 (D 4-6 MFT) and 1.6 (D 4-6 MFS) among the second graders. The mean caries enamel lesions among the first graders was 1.6 (D1-3T) and 2.2 (D1-3S) and among the second graders 2.1 and 3.0, respectively. The most affected surfaces were the occlusal surfaces of the lower first molars. The prevalence of sealants was very low-only 2.4% of the first molars were sealed among the first graders and 3.9% among the second graders. There were no statistically significant differences in caries experience or in the provision of restorative treatment between the schools. Caries experience is high in southeastern Estonia. Preventive programs are urgently needed.