<![CDATA[Essential oil’s component such as menthol and eucalyptol were already used as dental plaque inhibitors. In searching of potential dental plaque inhibitor from natural products, a study to explore the potency of essential oils extracted from several Indonesian medicinal plants against planktonic growth and biofilm adherence of S. mutans was performed. A total of 14 essential oils from some selected Indonesian medicinal plants were extractedby steam-hydro distillation. Antibacterial assay was performed against S. mutansby micro dilution technique on nutrient broth media. Biofilm formation inhibition assay was conducted on a flexible U-bottom 96-wells PVC micro plate by using BHI enriched with sucrose 2% at 36.6 °C for 18-24 h. After staining with 1% crystal violet, the optical density was read at 595 nm. A mouthwash commercial product containing essential oil component was used as a positive control. Result showed that the essential oils of C. sintoc exhibited the highest biofilm formation inhibition (IC50 = 0.005%), and Z. officinale showed the highest biofilm degradation with EC50 value of 0.013%. Both were active against bacterial planktonic growth but C. sintocshowed lower MIC90 value (0.6%) in comparison to Z. officinale(0.06%). Meantime, C. citratus was showed promising antibacterial and antibiofilmactivities with MIC90 value of 0.06%, MBC 0.6%, IC50 0.008% and EC50 0.026%. It is concluded that the essential oils of C. citratus, Z. officinaleand C. sintocare potential to be developed as dental plaque inhibitors.Key words: essential oils, antibacterial, biofilm, Streptococcus mutans]]>
