Prevention of mother-child transmission of mutans streptococci with xylitol

1. Prevention of mother-childtransmission of mutans streptococci with xylitol Eva Söderling Institute of Dentistry, University of Turku, Turku, Finland

2. Contents • Xylitol and dental caries • Mechanisms of action of xylitol • Mother-child transmission of mutans streptococci • Mother-child study: study design and results

3. Diet and dental caries • A healthy diet as such is no threat to teeth • Constant snacking is a risk to dental health!

4. Diet and dental caries… • Sugarfree products are useful in improving poor snacking habits • Xylitol is the most beneficial sugar substitute – suitable for self-care!

5. Xylitol/clinical studies • Xylitol is most effective in the caries prevention of eruptive teeth (Ylivieska 1988, Belize 1996, Estonia 2000) • The ”therapeutic” effects of xylitol appear only in habitual use and with high enough frequencies/doses

6. Estonian xylitol study(Alanen et al. 2000)

7. Xylitol adds to caries prevention obtained with fluorides, advice on diet and oral hygiene

8. Contents • Xylitol and dental caries • Mechanisms of action of xylitol • Mother-child transmission of mutans streptococci • Mother-child study: study design and results

9. Xylitol: a 5-carbon polyol • Xylitol is found in nature; fruits, berries... • Sweetness equal to sucrose • Natural component of the human metabolic pathways

10. Mechanisms of action • No acid production • Reduces plaque by suppressing formation of adhesive macromolecules, especially glucans • Selects for less virulent mutans streptococci (oral flora?) Xylitol:C5

11. No acid production from xylitol • No acid production in plaque even after long-term consumption • Creates conditions favouring remineralisation • specific effects on remineralisation? Xylitol:C5

12. No acid production from xylitol

13. No acid production from xylitol

14. The amount of plaque • Xylitol reduces plaque • ”Xylitol-plaque” shows low adhesiveness to the teeth, xylitol makes plaque easier to brush off • Xylitol suppresses formation of adhesive macromolecules, especially glucans

15. Xylitol reduces plaque

16. Xylitol reduces plaque formation

17. Xylitol chewing gum does not replace toothbrushing

18. Mutans streptococci • Xylitol selectively suppresses mutans streptococci • The effect on mutans streptococci is transient • Xylitol selects for less virulent mutans streptococci

19. Xylitol inhibits growth of mutans streptococci

20. Effect of xylitol pulsing on oral streptococci S.milleri S.mutans ADJ, 1991,36,213-5

21. Xylitol selects for mutans streptococci not inhibited by xylitol • Naturally occuring ms which do not form xylitol-5-P from xylitol can ”ignore” xylitol • These Xr cells form a small percentage of the ms if no xylitol is consumed • During regular xylitol consumption the Xr ms can multiply normally while ms inhibited by xylitol (Xs cells) decrease • Xr less virulent than Xs??

22. Effect of habitual xylitol consumption on plaque vs. saliva mutans streptococci levels Log CFU

23. Xylitol makes mutans streptococci to shed more easily to the saliva

24. Contents • Xylitol and dental caries • Mechanisms of action of xylitol • Mother-child transmission of mutans streptococci • Mother-child study: study design and results

25. S. Mutans infection in infants with and without oral development nodules (ODN). N children with nodules = 103, N without nodules = 85. Wan et al. JDR 2001. S.mutans infection in infants

27. The window of infectivity for mutans streptococci

29. The earlier the mutans streptococci are colonised, the higher is the risk for caries

32. 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

34. Reducing mutans streptococci in the mother during eruption of primary teeth: • Reduces on long-term basis the the mother-child transmission of mutans streptococci • Influences beneficially the future caries experience of the child

35. 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

36. Contents • Xylitol and dental caries • Mechanisms of action of xylitol • Mother-child transmission of mutans streptococci • Mother-child study: study design and results

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

39. Subjects • At baseline 195 mothers with high salivary ms counts • 2-year examination: 169 mother-child pairs • 6-year examination: 147 children

40. Study groups • Xylitol group: xylitol chewing gum (65%) appr.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

41. Xylitol chewing gum

42. CHX and F varnishes

43. Study design • Child 3 months: xylitol consumption starts in Xylitol group • Biannually: F or CHX varnish treatments in the F and CHX groups • Child 2 years: Xyl/F/CHX interventions discontinue • Annual follow-up of dental health • Microbiological follow-up

44. Microbiological methods • Saliva/mothers and plaque/children annually until the 3-year examination • Saliva/children at the 6-year examination • Plate culturing on MSB agar of both salivary and plaque mutans streptococci

45. Results

46. 7 . 5 7 . 0 6 . 5 6 . 0 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 A g e f c i l d ( y e a r s ) o h Mutans streptococci of the mothers: • High salivary mutans streptococci counts in all groups throughout the study • No differences between the study groups

47. Mother-child transmission of mutans streptococci • At two years of age, the children in the Xylitol group showed significantly less ms colonisation as compared to the control groups • At six-year of age, the Xylitol group still showed the lowest ms counts

48. Children showing mutans streptococci colonisation (%)

49. Childrens salivary mutans streptococci counts at 6 years Söderling et al.,2001

50. The results of plate culturing of mutans streptococci and the chairside SM Strip mutans test were in good agreement