Effect of anaerobic or/and microaerophilic atmosphere on microcosm biofilm formation and tooth demineralization

Author(s)

Aline Silva BRAGA ^[1] ; KIM Rafaela Ricci ^[2] ; Ana Carolina MAGALHÃES ^[3]

Affiliation

^[1] Universidade de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciências Biológicas - Brasil

^[2] Universidade de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciências Biológicas - Brasil

^[3] Universidade de São Paulo. Faculdade de Odontologia de Bauru. Departamento de Ciências Biológicas - Brasil

• Document type: Journal article
• Source: Journal of Applied Oral Science; v. 31, 2023-06-02.

Abstract

Abstract Microcosm biofilms can reproduce the complexity of a dental biofilm. However, different forms of cultivation have been used. The impact of the culture atmosphere on the development of microcosm biofilms and their potential to cause tooth demineralization has not yet been deeply studied. Objective This study analyzes the effects of three experimental cultivation models (microaerophile vs. anaerobiosis vs. experimental mixed) on the colony-forming units (CFU) of the cariogenic microorganisms and tooth demineralization. Methodology 90 bovine enamel and 90 dentin specimens were distributed into different atmospheres: 1) microaerophilia (5 days, 5% CO2); 2) anaerobiosis (5 days, jar); 3) mixed (2 days microaerophilia and 3 days anaerobiosis), which were treated with 0.12% chlorhexidine (positive control – CHX) or Phosphate-Buffered Saline (negative control – PBS) (n=15). Human saliva and McBain’s saliva containing 0.2% sucrose were used for microcosm biofilm formation, for 5 days. From the second day to the end of the experiment, the specimens were treated with CHX or PBS (1x1 min/day). Colony-forming units (CFU) were counted, and tooth demineralization was analyzed using transverse microradiography (TMR). Data were subjected to two-way ANOVA and Tukey’s or Sidak’s test (p<0.05). Results CHX was able to reduce total microorganism’s CFU compared to PBS (differences of 0.3–1.48 log10 CFU/mL), except for anaerobiosis and microaerophilia in enamel and dentin biofilm, respectively. In the case of dentin, no effect of CHX on Lactobacillus spp. was observed. CHX significantly reduced enamel demineralization compared to PBS (78% and 22% reductions for enamel and dentin, respectively). Enamel mineral loss did not differ when compared with the other atmospheres; however, the enamel lesion depth was greater under anaerobiosis. Dentin mineral loss was lower under anaerobiosis when compared with the other atmospheres. Conclusion The type of atmosphere has, in general, little influence on the cariogenic ability of the microcosm biofilm. (AU)

• FAPESP's process: 19/01730-9 - Effect of Stevia sweetener on the development of dental caries in enamel undera microcosm biofilm model
• Grantee: Rafaela Ricci Kim
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/17249-2 - Evaluation of the effect of different experimental and commercial natural extracts in the form of toothpastes and oral mouthrinses on the viability and activity of microcosm biofilm and on enamel demineralization prevention in vitro
• Grantee: Aline Silva Braga
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/21797-0 - Effect of artificial saliva substitutes and fluoride application on the development of root caries under a microcosm biofilm model simulating patients subjected to head and neck radiation
• Grantee: Ana Carolina Magalhães
• Support Opportunities: Regular Research Grants