Abstract:

Objective　To evaluate theNidus vespae′scario-static effect on biofilmmodelin vitro.Methods　Afour-or- ganism bacterial consortiumwas grown in a biofilmmodel on hydroxyapatite (HA) discs in a continuous culture system and exposed to repeated solution pulsing respectively. Therewere three parallel-connected flow cells in the model, sowere the three groupswith different solution pulsed in. Negative control group was pulsed with distilled water, positve control group was pulsed with 250 mmol/L sucrose solution aswell. While 4·0 g/LNidus vespaetogetherwith 250 mmol/L sucrose solutionwas pulsed in the experi- ment group. During the experiment, the pH responses against the pulses were recorded. After the 6 pulses, the biofilm surface structure was observed with a scan electron microscope and the population on the biofilmwas enumerated.Results　Nidus vespae can significantly inhibit the adherence ofStreptococcus mutanstoHA discs compared with the control group of 250 mmol/L sucrose pulsed in, and can facilitate the remove of acid products. It is also found that the extra-cellular polysaccharide is reducedwith the pulsing ofNidus vespae.Conclusion　Nidus vespaein the biofilm model can partially decrease the cariogenic response of sucrose solution pulsed in.

Key words: caries, biofilm modelin vitro, Nidus vespae