Full Length Research Paper

Polistes olivaceous decreases biotic surface colonization

Wings T. Y. Loo¹, L. J. Jin¹, Mary N. B. Cheung², Yi-ding Dou²* and J. P. Chen³

¹Faculty of Dentistry, the University of Hong Kong, Hong Kong.

²Jinhua Dentistry, Chengdu, Sichuan, China.

³School of Chinese Medicine, University of Hong Kong, Hong Kong.

*Corresponding author. E-mail: wtyloo@126.com. Tel: 86-13709003409.

Fax: 86-28-86677743.

Accepted 10 September, 2009

   Abstract

The objective of this investigation was to evaluate the anti-bacterial efficacy of the honeycomb of Polistes olivaceous on oral biotic surface (biofilm) model by means of pH response, population of oral bacteria and enamel mineralization. Three copies of a three-organism-bacterial consortium was grown on hydroxyapatite (HA) surfaces in a continuous culture system and exposed to repeated solution pulses of sucrose solution every 12 h to construct a cariogenic biofilm on the HA discs in the flow cells. One flow cell was only pulsed with 500 μmol/ml of sucrose (S group). The second flow cell was pulsed with 500 μmol/ml sucrose and 2.5 mg/ml P. olivaceous extract (P group). The third flow cell was pulsed with 500 μmol/ml sucrose, 230 mg/L sodium fluoride and 0.2% chlorohexidine digluconate (C group). During the course of carbohydrate supplement, the pH of the S group dropped sharply compared with the others. The P group demonstrated pH recovery to baseline more easily than the S group (p < 0.05). The C group demonstrated very little pH drop. The P group displayed a lower level of colonization than the S group, which was reflected by a lower cariogenic bacterial count and a less compact biofilm especially after the third pulse. P. olivaceous suppresses bacteria growth and accelerates pH recovery. P. olivaceous may have stabilizing effect against cariogenic shift on the oral biofilm, preventing tooth decay.

Key words: Polistes olivaceous, oral biotic surface (biofilm), hydroxyapatite, cariogenic bacteria, sucrose.