Mother-child transmission of mutans streptococci

1. Mother-child transmission of mutans streptococci

2. The window of infectivity for mutans streptococci

3. The earlier the mutans streptococci are colonized, the higher is the risk for caries

4. Transmission of mutans streptococci • The mother (infecting person) has high salivary mutans streptococci counts • Several daily saliva contacts between the child and the mother must take place

5. Methods to prevent the acquisition of mutans streptococci • Information on mother-child transmission of ms, advice on diet and oral hygiene • Chemical methods (chlorhexidine) • Xylitol

6. Mother-child study Eva Söderling and Pauli Isokangas Institute of Dentistry, Turku Ylivieska Health Centre, Ylivieska

7. Subjects • At baseline 195 mothers with high salivary mutans streptococci counts (60% of all mothers) • 2-year examination: 169 mother-child pairs • 6-year examination: 147 children

8. Study groups • Xylitol group: xylitol chewing gum 4 times a day • Fluoride (F; control) group: fluoride varnish (2.26%) treatments 2 times a year • Chlorhexidine (CHX) group: CHX varnish (40%) treatments 2 times a year All interventions discontinued when the child was 2 years old

9. Xylitol chewing gum

10. Only the mothers used xylitol/were treated with varnish; no additional treatments to children

11. Results

12. Mutans streptococci of the mothers: 7 . 5 7 . 0 • High salivary mutans streptococci counts in all groups throughout the study • No differences between the study groups 6 . 5 6 . 0 IogCF/ml F 5 . 5 X C H 5 . 0 X y l 4 . 5 4 0 . P r e g n a n c y 0 . 5 1 2 c i l d ( y e a r s ) A g e f o h

13. Mutans streptococci of the 2-year-old children (Söderling et al., JDR 2000) • The child’s risk of having mutans streptococci colonization in the dentition was 5-fold in the F group and 3-fold in the CHX group as compared to the Xylitol group

14. Caries occurence in children • At the age of 5 years the need of restorative treatment was 71-75% lower in the Xylitol group as compared to the F and CHX groups • The occurence of caries and early mutans streptococci colonization were in agreement

15. Prevention of Maternal-Infant Transmission of Caries A Randomized Clinical Trial

16. Investigator Affiliation University of Washington Schools of Dentistry, Medicine and Public Health Departments of Dental Public Health Sciences, Pediatrics, Health Services, Pediatric Dentistry

17. Background • Rates of early childhood caries 4.5 fold higher among Alaska Natives • High rates of caries likely related to: • high load of oral bacteria that cause caries • S. mutans, S. sobrinus • early acquisition • decreased fluoride exposure • large amounts of refined sugar in diet • poor oral hygiene

18. Specific Aim • To determine if the infants of pregnant mothers who use CHX mouth rinses for two weeks, followed by xylitol gum use for two years, experience less dental decay compared to infants of mothers who do not use these interventions

19. Methods: Design • Randomized controlled trial • 2 arms: intervention vs. control • double-blinded

20. Yukon-Kuskokwim Delta

21. Subjects • Enroll: Pregnant mothers at 36-38 weeks of gestation • Track outcomes: • Mothers • Liveborn children who are offspring of enrollees • Exclude: infants born in Anchorage, infants with congenital anomalies

22. Intervention: Both Groups • Dental hygiene and exam • Restoration of caries and extractions as necessary • Dental and dietary counseling/education • Toothbrushes and toothpaste

23. Intervention Group Only • Chlorhexidine rinses, twice a day for two weeks; starts at enrollment • Xylitol gum 5.1 grams per day (3x/day) for two years

24. Outcome Assessment • Outcomes of interest • caries among infants at 1 and 2 years of age • all enrolled children • deft • S. mutans counts for mothers and infants at same time intervals • for subset (n=30) only

25. Data Collection • Baseline: • maternal dental exam • maternal gingival culture (subset) • maternal oral health questionnaire • T1 (infant age= one year) • oral health questionnaire • infant dental exam • infant and maternal gingival cultures (subset)

26. Data Collection • T2 (infant age=2 years) • oral health questionnaire • infant dental exam • infant and maternal gingival cultures (subset)

27. Analysis • Compare rates of caries between intervention and control groups • (unit of analysis: child or teeth) • Compare S. mutans counts between groups • Control for confounding factors, if present

28. Potential limitations • Compliance with intervention • Blinding • Misclassification of exposure • e.g. control mom uses intervention • mother doesn’t rear child • Intensification of exposure • e.g. whole family uses gum

29. Sample Size Estimates • N=375 births/year • Exclude 25% born in Anchorage • Assume 10% refusal rate • Enroll approximately 125 in each group • Assume 80% follow-up at two years • Need about 200 at final follow-up • About 90% power to detect a 50% reduction in the intervention group

30. Future studies…

31. Xylitol administration with a slow-release pacifier for AOM and ECC?

32. Diet and dental caries

33. Subsidizing toothpaste, introducing xylitol snacks

34. What is most impressive about xylitol is its safety

35. Effectively addressing caries will require new and better tools for public health

36. THANK YOU