Original article / research
Effect of Liquorice Extract on Oral Health: A Systematic Review and Meta-analysis
ZC01-ZC06
Correspondence
Kiruppashini Thiagarajan,
C60, Syed Fakrudeen Street, Gandhinagar, Udumalpet-642154, Tamil Nadu, India.
E-mail: tkapple34@gmail.com
Introduction: Oral diseases continue to be a significant global public health challenge. Chlorhexidine (CHX) is widely regarded as the gold standard for chemical plaque control; however, its prolonged use is linked to adverse effects. Herbal alternatives such as Glycyrrhiza glabra (liquorice) have gained attention due to their antimicrobial and anti-inflammatory properties.
Aim: To systematically evaluate the clinical effectiveness of liquorice extract on dental caries, plaque, gingivitis, Recurrent Aphthous Stomatitis (RAS), and oral mucositis through systematic review and meta-analysis.
Materials and Methods: This systematic review and metaanalysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Metanalyses (PRISMA) guidelines and registered in International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023476073). Electronic databases, including PubMed, EMBASE, Web of Science, Cochrane, and Google Scholar, were searched from 2017 to 2023. Only RCTs published in English were included. Two independent reviewers screened studies, extracted data, and assessed risk of bias using the Cochrane Collaboration tool. Meta-analysis was performed using Review Manager (RevMan) version 5.4.1 software.
Results: Out of 1,677 records identified, seven RCTs met the inclusion criteria for qualitative synthesis, and six were included in quantitative meta-analysis. Liquorice extract demonstrated significant reduction in Streptococcus mutans levels, DMFT scores, pain scores in RAS, and mucositis severity compared with placebo/control. However, in plaque and gingivitis reduction, chlorhexidine showed greater clinical improvement than liquorice. Substantial heterogeneity was observed in pooled analyses (I2 =98%).
Conclusion: Liquorice extract exhibits promising antimicrobial and anti-inflammatory properties in the management of dental caries, aphthous ulcers, and mucositis. However, current evidence does not conclusively support its superiority over chlorhexidine for plaque and gingivitis control. High-quality, adequately powered RCTs with standardised concentrations and longer follow-up are required before recommending liquorice as a definitive alternative to chlorhexidine.