Etiology: Bacteria

Cariogenic bacteria (including streptococci mutans and lactobacilli) are transferred two ways:

  1. Vertical transmission from the primary caregiver, most often the mother, via saliva contact
  2. Horizontal transmission from family members and care providers, such as in school and daycare settings

The higher the bacteria level in the caregiver's mouth, the more likely the child will become colonized with mutans streptococci.

Caregivers with high bacteria levels usually have:

  • High frequency of sugar intake
  • Poor oral hygiene
  • High levels of dental caries

Evidence supports that caregivers can decrease their risk of passing on cariogenic bacteria to their children by decreasing their own caries levels.

Mutans Streptococci


Caregivers can optimize their oral health and that of their children by:

  • Receiving regular comprehensive dental care
  • Limiting the frequency of sugar in the diet
  • Maintaining excellent oral hygiene and using fluoride containing toothpaste
  • Using preventive agents, in appropriate age groups, such as:
    • Topical fluorides
    • Antibacterial mouth rinses, such as chlorhexidine
    • Xylitol containing gums


Manchanda S, Sardana D, Liu P, et al. Horizontal Transmission of Streptococcus mutans in Children and its Association with Dental Caries: A Systematic Review and Meta-Analysis. Pediatr Dent 2021; 43(1):E1-E12.

Aas JA, Griffen AL, Dardis SR, et al. Bacteria of Dental Caries in Primary and Permanent Teeth in Children and Young Adults. J Clin Microbiol. 2008; 46(4): 1407–1417.

Köhler B, Lundberg AB, Birkhed D, Papapanou PN. Longitudinal study of intrafamilial mutans streptococci ribotypes. Eur J Oral Sci. 2003;111(5):383-9.

Weintraub JA et al. Mothers' caries increases odds of children's caries. J Dent Res. 2010; 89(9):954-8.

Zhan L, Tan S, Den Besten P, Featherstone JD, Hoover CI. Factors related to maternal transmission of mutans streptococci in high-risk children-pilot study. Pediatr Dent. 2012; 34(4): e86-91.