How caries-causing bacteria can survive in dental plaque

November 2, 2017, University of Basel
Credit: Universität Basel

Cariogenic bacteria live in biofilm and attack dental enamel by converting sugar and starch into acids that dissolve out calcium from the enamel. This process can cause caries. The dissolution of calcium increases the concentration of calcium locally, creating an environment that is hostile to bacterial life. In their study, the researchers investigated how bacteria manage to survive in dental plaque despite these conditions.

They hypothesized that extracellular polysaccharides (EPS) support the bacteria's survival capabilities. EPS are substances that build extracellular cariogenic bacteria from sugar residue. They create the biofilm's scaffolding and ensure that bacteria are able to anchor themselves in the .

EPS integrate calcium into the biofilm

The study showed that the more cariogenic bacteria dissolve, the greater their calcium tolerance and survival capability in the biofilm becomes. The scientists were able to prove that cariogenic bacteria develop mechanisms to help them survive the high concentrations of calcium.

They demonstrated that extracellular polysaccharides possess a high number of calcium binding sites through which they can integrate the free calcium into the biofilm. This neutralizes the toxic substance and strengthens the EPS structure of the .

New insights into the causes of caries

The EPS' integration of calcium doesn't just help cariogenic bacteria to survive in dental enamel; it also causes caries. "EPS' integration of calcium inhibits the remineralization of the enamel, as there is no longer sufficient free calcium present in the plaque. This discovery is important in gaining a better understanding of in caries," explains microbiologist Monika Astašov-Frauenhoffer.

Explore further: Calcium intake and colorectal cancer

More information: Monika Astasov-Frauenhoffer et al. Exopolysaccharides regulate calcium flow in cariogenic biofilms, PLOS ONE (2017). DOI: 10.1371/journal.pone.0186256

Related Stories

Calcium intake and colorectal cancer

October 19, 2017
Calcium plays key roles in cellular signaling, proliferation and death. Previous studies exploring the relationship between dietary calcium intake and colorectal cancer have had contradictory results, perhaps due to no consideration ...

Researchers identify new dental cavity-causing species

May 17, 2011
A team of scientists from Boston has confirmed that the bacterium Streptococcus mutans is a primary culprit in early childhood caries (EEC) cavities on the first set of teeth, and has identified a new species of bacterium, ...

Calcium in the prevention of postmenopausal osteoporosis

October 12, 2017
A new clinical guide summarizes the evidence regarding the effects of calcium in reducing the risk of osteoporosis after the menopause.

Small molecule inhibitor prevents or impedes tooth cavities in a preclinical model

August 10, 2017
University of Alabama at Birmingham researchers have created a small molecule that prevents or impedes tooth cavities in a preclinical model. The inhibitor blocks the function of a key virulence enzyme in an oral bacterium, ...

Chemical composition and microhardness of human enamel treated with fluoridated whintening agents

June 12, 2017
Aesthetic treatments are always widely sought by dental patients, especially dental whitening, in order to get whiter smiles. The big demand for this type of procedure raises the concern in the dental research community that ...

Cellular calcium handling in diabetes

September 29, 2017
Tight regulation of calcium levels in the endoplasmic reticulum (ER) – a cellular organelle with multiple functions – contributes to insulin secretion by pancreatic beta cells. Although ER calcium handling is perturbed ...

Recommended for you

Painless dental lasers can render teeth cavity-resistant

November 21, 2017
Almost as soon as lasers were invented in the 1960s, curious dentists wondered if these powerful forms of light could be used on teeth, though those early lasers were much too crude for any useful dental work.

Nanodiamonds show promise for aiding recovery from root canal

October 23, 2017
People who undergo root canals may soon have a tiny but powerful ally that could prevent infection after treatment.

Research shows aspirin could repair tooth decay

September 8, 2017
Researchers at Queen's University Belfast have discovered that aspirin could reverse the effects of tooth decay resulting in a reduction in the need for fillings. Currently about 7 million fillings are provided by the NHS ...

New dental imaging method uses squid ink to fish for gum disease

September 7, 2017
Squid ink might be a great ingredient to make black pasta, but it could also one day make getting checked for gum disease at the dentist less tedious and even painless. By combining squid ink with light and ultrasound, a ...

A new dental restoration composite proves more durable than the conventional material

August 21, 2017
Fewer trips to the dentist may be in your future, and you have mussels to thank.

Understanding genetic synergy in cleft palate

July 19, 2017
Like all of the individual elements of fetal development, palate growth is a marvel of nature. In part of this process, ledges of tissue on the sides of the face grow downwards on each side of the tongue, then upward, fusing ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.