The difference of antibacterial effect of neem leaves and stick extracts

Widowati Siswomihardjo, DDS, MSc, PhD,(a) Siti Sunarintyas Badawi, DDS, MSc, PhD,(a) Masahiro Nishimura, DDS, PhD,(b) and Taizo Hamada, DDS, PhD(b)

(a)Department of Biomaterials, Faculty of Dentistry, Gadjah Mada University, Jogjakarta, Indonesia
(b)Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan

Purpose: This study determined the antibacterial effect of ethanolic neem leaves and stick extract in inhibiting the growth of Sreptococcus mutans.
Materials and Methods: Two different parts of neem, leaves and stick, extracts using ethanol were prepared at 10% and 20% (w/v: extraction powder/water) respectively. Each extractions were dropped on an MHA agar that had been inoculated with Streptococcus mutans. Distilled water was used as the control. After 24 hours of incubation, the inhibition diameters were measured. Collected data were analyzed by analysis of variance (ANOVA) followed by Least Significance Difference (LSD) at a 95% confinement level.
Results: The inhibition zone value of neem extracts on Streptococcus mutans showed that neem leaves extract had less inhibition value than neem stick extract on all concentrations. The ANOVA showed that there were significant influence of neem extracts (p<0.001), neem concentrations (p<0.001), and neem extract- concentration (p<0.023) on Streptococcus mutans inhibition.
Conclusion: Neem leaves and stick ethanolic extracts had antibacterial effect on Streptococcus mutans. Neem stick extract had higher antibacterial properties than the leaves extract. (Int Chin J Dent 2007; 7: 27-29.)

Key Words: antibacterial effect, neem extracts, Streptococcus mutans.