1. 1College of Dentistry, Baghdad University
1220
Black and Green Tea Antimicrobial properties: in-vitro and in-vivo study
Minan Y. Al-Ezzi1, 2, Abbas S. Al-Mizrakchi1, Athra’a M. Al-Weheb1, Aylin Baysan2, Noha Seoudi2, Anwar R. Tappuni2
1College of Dentistry, Baghdad University
2Barts and the London School of Medicine and Dentistry, Queen Mary University of London
Introduction
Finding an affordable natural product with anti-cariogenic potential will have a great impact on the management of dental caries worldwide. There is some published evidence supporting the effect of green tea (GT) (Refernces) but studies of the antibacterial potential of black tea (BT) is scanty.
Aims and objectives
To determine the in-vitro effect of BT and GT on the viable counts of cariogenic bacteria and on their ability to adhere to tooth surface.
To investigate the in-vitro efficacy of BT and GT in adsorbing to the tooth surface and in inhibiting cariogenic bacteria in comparison to known anti-cariogenic agents; NaF and CHX.
To determine the in-vivo effect of aqueous extract of BT and GT on the salivary counts of MS and LB.
In-vivo study (n=30)
Effect of rinsing with 50% BT aqueous extract on the viable count of Mutans streptococci and Lactobacilli of volunteers.
Effect of rinsing with 50% GT aqueous extract on the viable count of Mutans streptococci and Lactobacilli of volunteers.
Effect of rinsing with distilled water on the viable count of Mutans streptococci and Lactobacilli of volunteers.
The effect of BT and GT aqueous extract on the mean count of Mutans streptococci (in vitro).
The effect of BT and GT aqueous extract on the mean count of Lactobacilli (in vitro).
Methodology
- Ethical approval was obtained from the Faculty of Dentistry local Ethics Committee, Baghdad University.
Two commercially available grounded dried leaves of BT (Lipton Yellow Label, Sri Lanka) or GT (Twinings, London, England) were used to prepare the aqueous or alcoholic extracts.
Twenty isolates of mutans streptococci (MS) and lactobacilli (LB) were obtained under standardised conditions from 20 dental students.
Testing the effect of BT and GT aqueous and alcoholic extract on the sensitivity, viable count, adsorption, adherence and time-kill in-vitro after determining of the minimum inhibitory concentration (MBC). Testing the aqueous extract effect in-vivo.
In-vitro studies (n=20)
Comparison of the mean diameter of inhibition zones of BT and GT aqueous extract, CHX and NaF effect on Mutans sterptococci.
Comparison of the mean diameter of inhibition zones of BT and GT aqueous extract, CHX and NaF effect on Lactobacilli.
Comparison of the mean diameter of inhibition zones of BT and GT aqueous extract, CHX and NaF effect on oral microfloa
Comparison of the mean diameter of inhibition zones of BT and GT alcoholic extract effect on Mutans streptococci.
Comparison of the mean diameter of inhibition zones of BT and GT alcoholic extract effect on Lactobacilli
Inhibitory effect
Sensitivity of MS on MSB agar to the aqueous extract of BT and GT, NaF and CHX by agar diffusion technique. GT has better results.
30% GT
30% BT
2% NaF
0.2% CHX
Results
The bacterial counts of MS and LB were reduced with BT or GT aqueous extract significantly and progressively with time. The largest inhibition zone was produced by 50% GT aqueous extract. The least viable count of LB was recorded with 30% BT aqueous extract. The minimum bactericidal concentration was 35% for BT and 30% for GT aqueous and alcoholic extracts. In the in-vivo study, the maximum reduction of MS viable count was at 30 minutes and for LB was at 15 minutes after rinsing with 50% GT.
Baseline
Baseline
Baseline
Main findings and conclusion
Our study showed that BT and GT extracts have antibacterial activity against MS and LB but larger scale clinical trials are needed to provide stronger evidence for the effectiveness of using tea extract as an anticariogenic agent.
Main findings and conclusion