Analysis of antimicrobial effect and antibiofilm of two toothpastes at different fluorine concentration

BACKGROUND: Our research was focused on the analysis of the antimicrobial and antibiofilm power of two commonly used oral toothpastes containing different concentrations of fluorine. These toothpastes were tested in vitro on deciduous teeth. METHODS: Culture of S. mutans was inoculated in 1 mL of sterile phosphate buffered saline (PBS) with a 5% of toothpaste concentration with 500ppm e1400ppm of fluorine. The ability of the bacteria to form colonies was measured by counting the number of Colony Forming Units (CFU). Results were compared with the control sample, represented by untreated solution. Later a selection of 20 deciduous molars was prepared. The teeth were extracted as a result of orthodontic treatments or physiological replacements. The procedures were performed at the UOC of Pediatric dentistry Sapienza University of Rome department of Oral and Maxillo-Facial Science. Each element, was preserved in normal saline and then sectioned at a cementum-enamel junction level. Successively the external and occlusal surfaces have been etched with 37% orthophosphoric acid for 1 minute in order to reproduce the demineralization that occurs in the oral environment. Subsequently, 10 elements were treated, by manual brushing, with a toothpaste containing 500 ppm of fluorine, the remaining 10 with a toothpaste at 1400 ppm of fluorine. The brushing process was performed with a duration of two minutes, three times a day for a period of 15 days. In a second phase, each sample was exposed to a bacterial suspension of S. mutans for biofilm cultivation. After growing, a Crystal Violet (CV, Sigma) assay was performed to quantify biofilm formation on teeth samples. RESULTS: The microbiological tests performed on 5% solutions of the two toothpastes, compared to the untreated aqueous solution (UT), showed a statistically very similar antimicrobial effect. The viability rate of bacterial colonies decreases with the passage of exposure time and is similar for the two products. The analysis of bacterial biofilm formation on the surfaces of the dental elements indicates an inhibiting action of the biofilm, similar for both toothpastes. CONCLUSIONS: The present study demonstrated that the use of two toothpastes has been shown to have similar antimicrobial and antibiofilm characteristics. The use in pediatric patients of a low-fluoride toothpaste as well as providing protection against the bacterial attack also reduces the potential risk of fluorosis.