动物造模,药效评价,龋齿动物 z-bio 2024-07-08 694

　　Caries is a progressive damage to dental hard tissue caused by a combination of factors such as bacteria, food, host, and time. If left untreated, the disease can continue to develop, leading to the formation of caries cavities and secondary pulpitis and periapical periodontitis. It can even cause inflammation of the alveolar and jawbone, ultimately leading to complete destruction of the affected tooth crown or loss of the entire tooth. Caries is characterized by high incidence rate and wide distribution. It is the most common disease in oral cavity and one of the most common diseases in human beings. The World Health Organization has listed it as one of the three major diseases to be prevented and treated by human beings, along with tumors and cardiovascular diseases.

　　The currently recognized etiology of dental caries is the quadruple factor theory, which mainly includes bacteria, oral environment, host, and time. Its basic principle is that cariogenic foods (especially sucrose and refined carbohydrates) adhere tightly to the obtainable membrane formed by salivary proteins on the tooth surface. This type of acquired membrane can not only firmly adhere to the tooth surface, but also have enough time at suitable temperatures to produce acid in the deep layer of the plaque, invade the teeth, cause demineralization, and ultimately damage organic matter, resulting in cavities. Pathogenic bacteria mainly include Streptococcus mutans, Streptococcus salivarius, and Lactobacillus fermentus. Therefore, animal models of dental caries mainly replicate around two major pathogenic factors: bacteria and food.

　　There are various types of experimental animals used for dental caries animal models, but more mature models often use rodents. The basic modeling methods include inoculating Streptococcus mutans on the tooth surface of experimental animals, feeding high sugar foods, and inhibiting saliva secretion.

　　Taking rats as an example, this article provides a detailed description of the method for establishing a dental caries model. After reviving Streptococcus mutans strains under anaerobic conditions at 37 ℃ for 48 hours, they were inoculated into liquid culture medium of tryptic soy broth. Under anaerobic conditions at 37 ℃, they were cultured for 18-24 hours. After smear examination, a small amount of Streptococcus mutans was taken and inoculated into tryptic soy agar medium, and 1 × 100000000 CFU/ml (CFU, colony forming unit) standard bacterial solution was prepared for later use. Select 3-week-old Wistar rats, dip a cotton swab into a standard bacterial solution containing Streptococcus mutans and apply it to the tooth surface of the rats. Inoculate once a week and ensure that each rat is fed 15-20g of cariogenic high sugar food daily. The main components of high sugar foods that cause caries per 100g include: 60g sucrose, 10g wheat flour, 10g casein, 10g milk powder, 3g bone powder, 3g peanut oil, 2g yeast, 1g sodium chloride, 1g various vitamins and trace elements, etc. To inhibit saliva secretion, 0.1mg of atropine is added to every 100g of cariogenic food. Caries begin to appear 50 days later and worsen over time.

　　【 Model Features 】 This animal model is similar to human caries and its occurrence and development process.

　　The selection of animal models for dental caries should be determined based on the research purpose. This model can be used to study the mechanism of dental caries, the interrelationships between various cariogenic factors, and to evaluate caries prevention measures and treatment methods at different time periods. If a special caries model needs to be established, the following methods can be used: ① Salivary gland removal animal model: After removing the salivary glands of Sprague Dawley rats, they are fed with high sugar food, and at 3 weeks, extensive caries can form in the rat molars; ② Root caries model: After gingivectomy in Sprague Dawley rats, they were inoculated with Streptococcus sobrinus and Actinobacteria viscosus, and provided with a high sugar diet. Within 7 weeks, a large amount of root caries could form; ③ Validation of the anti caries efficacy model of chemical agents: instead of inoculating cariogenic bacteria on animal teeth, the intrinsic oral bacteria of Wistar rats were utilized, and a high sugar diet was fed to induce caries. This model can produce a significant dose response to fluoride and effectively predict the anti caries efficacy of fluoride toothpaste in clinical trials; ④ Model for evaluating food caries susceptibility: Select experimental animals with high caries susceptibility for modeling; ⑤ Research on animal models for immune caries prevention: After infecting experimental animals with Streptococcus mutans and administering cariogenic feed to induce caries, different immune pathways can be applied to the experimental animals.