Stop tooth decay without killing beneficial bacteria

Recent scientists have reported a treatment that can stop the formation of plaque and caries using a new type of cerium nanoparticle formulation that will be applied to teeth in the dental clinic in the future.

The mouth contains more than 700 species of bacteria. This includes beneficial strains that help digest foods and control other microorganisms, including streptococcal species such as Streptococcus mutans that begin to attach to teeth and immediately after cleaning. Contains multiple harmful strains. Using sugar as an energy source and using these harmful microbes as building blocks, a tough film is gradually formed. As they continue to metabolize sugar, they also make acid by-products that can dissolve tooth enamel, making your teeth more prone to caries.

You can fight with stannous fluoride, which suppresses plaque, and products such as silver nitrate and silver fluoride that help stop existing caries. Nanoparticles made from zinc oxide have also been studied, according to Russell Pesavento (DDS, PhD), a principal investigator at the University of Illinois in Chicago, but repeated application can lead to tooth smear and bacterial resistance. .. “Also, these drugs are not selective, so they kill many types of bacteria in the mouth. He explains.

Researchers investigated the microbial cerium oxide nanoparticles to find alternatives that did not kill the beneficial oral bacteria. The team dissolved cerium ammonium nitrate or sulfate in water to produce nanoparticles. When polystyrene plates were seeded with S. mutans in growth medium and bacteria were given sugar in the presence of cerium oxide nanoparticles solution, those formulations produced 40% more biofilm growth compared to plates without nanoparticles. It turned out to be reduced. However, the team was unable to remove the existing biofilm, and it was pointed out that silver nitrate did not affect biofilm growth under similar conditions.

“The advantage of our treatment is that it looks less harmful to oral bacteria and often does not kill them.” Says Pessavent. Instead, the nanoparticles only prevent microorganisms from attaching to the polystyrene surface and forming an adherent biofilm. Furthermore, the toxic and metabolic effects of nanoparticles on human oral cells in Petri dishes were less than those of silver nitrate.

Pessavent was patented in July 2020 and wants to further advance his prescription so that the dentist can apply it to the patient’s teeth. Before that happens, the team points out that there is still a lot to do. The team is currently working on a coating that helps stabilize nanoparticles at a neutral or slightly basic pH that is closer to the pH of saliva and healthy teeth than current solutions. The team is also investigating bacteria associated with the development of gingivitis to limit adherent biofilms.

Overview:

“Streptococcus mutans have been the subject of interest in antibacterial therapy in the field of oral medicine. S. mutans is a potent tooth-derived bioagent that is a major causative factor in the progression of caries and odontogenic infections. Produces a film.Silver-based fungicides have been shown to be effective in reducing the growth of oral S. mutans, but repeated administration of them produces new bacterial resistance and oral cavity resistance. Concerns about harmful effects on microbiota: Biofilm inhibitors applied to teeth with a non-lethal mechanism of action limit biofilm formation and reduce effects on the entire oral microbiome The use of nanoparticles in this capacity has been of considerable interest in recent years. Several studies have focused on the antibacterial effect of cerium oxide nanoparticles (nanoceria, CeO2-NP). However, few focus on the impact on clinically relevant bacteria under early biofilm formation conditions. In this study, Ce(IV) salts (ie cerium ammonium nitrate, Hydrolysis of nano-ceria derived solely from CAN, cerium ammonium sulphate (CAS) has been shown to commercially reduce the growth of adherent in vitro S. mutans in the presence of sucrose by approximately 40%. Only nanoceria (3 nm, 10-20 nm, 30 nm), Ce(NO3)3(CN) or ammonium salt (AN, AS) dispersions are inactive or biofilm-formed in vitro as well Was observed to increase slightly. Plankton growth and dispersion assays support a non-sterile mode of active biofilm inhibition during the early stages of biofilm production. The human cell proliferation assay suggested only a slight effect of hydrolyzed Ce(IV) salts on cell metabolism at concentrations up to 1 mM Ce, with no observed toxicity compared to equimolar concentrations of AgNO3. Yes-An oral antibacterial agent used for a long time. The results presented here have potential applications in the field of oral medicine. “