Arginine can reverse plaque formation on teeth and protect against tooth decay

A new human clinical trial proves that arginine, an amino acid, can alter the formation of plaque in teeth, thereby protecting against tooth decay.

A new human clinical trial shows that arginine, an amino acid, can alter the formation of plaque on teeth, thus protecting against cavities.

An interesting human experiment conducted by researchers at Aarhus University in Denmark compared the dental plaque that grew on traditional dentures on both sides of the same participant's mouth.The team exposed both groups to sugar, but treated only one with arginine to assess its benefits.Their findings showed a higher pH, a changed biofilm, and a reduced amount of harmful bacteria, showing the power of arginine in preventing tooth decay.

A large number of bacteria in our mouths ferment the sugars in food, producing acids that damage teeth and form cavities.These bacteria live in plaque-like communities called dental biofilms.Arginine is an amino acid found naturally in saliva that has been shown to help prevent tooth decay.Some beneficial bacteria contain an enzyme called arginine deiminase, which helps break down arginine to form a base that neutralizes acids.System (ADS).The increased availability of arginine helps these beneficial bacteria proliferate while also inhibiting the growth of acid-producing bacteria.Recent in vitro studies have shown that arginine availability alters the composition of dental biofilms.

To further confirm these results in the human mouth, a team of dentists and researchers led by Post.doc.Yumi C. Del Rey and Professor Sebastian Schlafer of Aarhus University, Denmark, conducted a clinical trial and published the results in the International Oral Journal.

They recruited 12 participants with active caries and prepared specialized dentures that allow the collection of intact biofilms, covering both sides of the jaw.The participants were instructed to immerse the dentures in a sugar solution for 5 minutes and then in distilled water (or placebo) or arginine for 30 minutes, one on each side.This would be repeated three times a day, with the arginine treatment on the same side each time.The aim was to investigate the effect of the treatment arginine on the acidity, type of bacteria and carbohydrate matrix of the biofilm of patients with active caries," explains Sebastian Schlafer, professor at the Department of Dentistry and Oral Health.

A special pH-sensitive dye called "C-SNARF-4" was used to analyze the acidity of biofilms collected in different areas.Biofilms formed with arginine showed a very high pH (low acidity) 10 and 35 minutes after the glucose challenge.sugar," says first author Yumi C. Del Rey.

Furthermore, carbohydrate-binding proteins called lectin, which are called fluorescent dyes, are used to color two types of carbohydrate components in the biofilm: fucose and galactose.These products make up a large part of the dental biofilm and can contribute to the creation of "acid pockets" inside.With arginine treatment, a total reduction was observed in the amount of fucose-based carbohydrates, possibly making the biofilm worse.therefore, there is a change in the structure of the biofilm, with carbohydrates containing galactose decreasing at the bottom and increasing at the top.

Furthermore, to determine which bacteria were present in the biofilm, they sequenced all the bacterial genomes using a technique called "16S rRNA gene sequencing."Although arginine- and placebo-treated biofilms were predominantly dominated by Streptococcus and Loenella species, arginine significantly reduced the acid-producing Streptococcus hemitis/oralis group.was produced but was not a strong producer of alkali, and greatly increased the streptococci.Overall, arginine made the biofilms less harmful by reducing their acidity, changing their carbohydrate structure, and reshaping the microbiome within them.

Dental caries, prevalent in all ages and regions, can be combated by using strategies such as supplementing arginine in toothpaste or oral rinse for those who are more sensitive to it.Arginine, an amino acid that occurs naturally in our bodies and is present in dietary proteins, is harmless and can be used by children.

Del Rey, Y.C., et al.(2025).Arginine modulates the pH, microbial composition and matrix architecture of caries-active patient biofilms.International Journal of Oral Sciences.DOI: 10.1038/s41368-025-00404-5.https://www.nature.com/articles/s41368-025-00404-5