Oral static biofilm model is an important tool for in vitro simulation of oral microecological environment, which has become an important method for studying the pathogenesis of various oral diseases and testing the efficacy of various drugs, oral care products and foods due to its low cost, high throughput, good reliability and easy operation. The establishment of oral static biofilm models allows the selection of different devices, inoculum sources, media, substrates and culture conditions according to the purpose of the study, and the evaluation of biofilm growth by various methods such as measuring biomass, metabolic activity, community structure and performing visualization analysis. This paper summarizes the methodological elements reported in recent years for the establishment and evaluation of oral static biofilm models, and analyzes and discusses the applicability of various methods in the hope of contributing to the research and production practice in related fields.
Biofilms ; Reproducibility of Results

ObjectiveTo investigate the possible mechanism of Hewei Anshen Formula （和胃安神方） in the treatment of insomnia. MethodsSixty male SD rats were randomly divided into the normal group， the model group， the eszopiclone group and the low-， medium- and high-dose Hewei Anshen Formula groups. The insomnia model was constructed by intraperitoneal injection of p-chlorophenylalanine （PCPA） for 2 days in all groups except the normal group. After successful modelling， the eszopiclone group was given 0.33 mg/（kg·d） eszopiclone aqueous solution by gavage， the low-， medium- and high-dose Hewei Anshen Formula groups were given 10 ml/kg of Hewei Anshen Formula with a concentration of 1， 2 and 4 g/ml， respectively， and the rats in the normal group and the model group were given 10 ml/kg of saline by gavage， once a day for 7 consecutive days. The general condition of the rats was observed during the experiment， and the body mass of the rats was measured every day after medication administration. The following day after the last medication administration， pentobarbital sodium co-test was used to observe the sleep condition， and the sleep latency and sleep duration were recorded； immunohistochemistry and Western blot were used to detect the expression of hypothalamic clock rhythm regulating protein （CLOCK） and brain and muscle aromatic hydrocarbon receptor nuclear transporter-like protein 1 （BMAL1） in the rats. ResultsThe body mass of rats in the model group was lower than that of rats in the normal group at all time points （P＜0.01）； compared with the same time in the eszopiclone group， the body mass of rats in the low-dose Hewei Anshen Formula group was elevated on the 5th， 6th and 7th days of medication administration （P＜0.05）. Compared with the normal group， the sleep duration of rats in the model group was shortened （P＜0.01）； compared with the model group， the sleep duration of rats in each dosage group increased （P＜0.01）， and the difference between the high-dose Hewei Anshen Formula group and the eszopiclone group showed no statistically significant （P＞0.05）， while the sleep duration of the low- and medium-dose Hewei Anshen Formula groups were shorterned than the eszopiclone group （P＜0.01）. The difference in sleep latency showed no statistically significant among each group （P＞0.05）. The results of both immunohistochemistry and Western blotting showed that the expression of CLOCK and BMAL1 in the hypothalamus of rats in the model group was significantly reduced compared with that in the normal group （P＜0.01）； the expression of CLOCK and BMAL1 in the hypothalamus of rats in the low- and high-dose Hewei Anshen Formula groups increased than that in the model group （P＜0.05 or P＜0.01）. ConclusionHewei Anshen Formula can improve insomnia in model rats， and its mechanism of action may be related to the up-regulation of the expression of the hypothalamic biological clock genes CLOCK and BMAL1 protein.