Clinical reduction of S. mutans in pre-school children using a novel liquorice root extract lollipop: a pilot study

Eur Arch Paediatr Dent. 2010 Dec;11(6):274-8. doi: 10.1007/BF03262762.


Aim: To determine the clinical effect of a simple herbal caries-prevention protocol aimed at reduction of Streptococcus mutans (SM) in young children in a pre-school setting.

Study design: Proof-of-principle pilot study.

Methods: To prove the concept this pilot study delivered a clinical intervention using sugar-free lollipops containing liquorice root extract. Regimen: Supervised herbal lollipops, twice daily for 3 weeks. Species-specific monoclonal antibody testing of saliva provided SM counts. Children were grouped in high, medium and low caries-risk using baseline SM-levels as risk-indicator. Bacterial numbers at baseline, during intervention, and for 9 weeks post-intervention were compared.

Statistics: SM levels were analysed using GEE modelling.

Results: High-risk children showed the steepest early decrease in mean log-SM (P<.001). At end of a follow-up period, the log-SM decrease moved the high-risk group down to moderate-risk level. High-risk children showed a decrease in fitted mean SM% not seen in other groups (P<.001). The decrease reached a nadir around 22-days post-intervention. Twice-daily use of herbal lollipop significantly reduced both number and relative percent of SM in high-risk children. SM numbers were reduced for 22 days after the last lollipop, stabilized and then began to rebound.

Conclusion: A potential for simple effective caries-prevention for high-risk children has been demonstrated. Encouraging results warrant randomised clinical trials (RCT) of liquorice root in herbal lollipops or alternative modes of delivery.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Bacterial Load
  • Candy*
  • Child, Preschool
  • Dental Caries Susceptibility
  • Early Intervention, Educational
  • Female
  • Follow-Up Studies
  • Glycyrrhiza*
  • Humans
  • Male
  • Phytotherapy
  • Pilot Projects
  • Plant Extracts / therapeutic use*
  • Plant Roots
  • Pterocarpans / therapeutic use
  • Saliva / microbiology*
  • Streptococcus mutans / drug effects
  • Streptococcus mutans / isolation & purification*


  • Anti-Bacterial Agents
  • Plant Extracts
  • Pterocarpans
  • glycyrrhizol A
  • glycyrrhizol B