Maintenance of good oral health is more important than use of antibiotics in dental procedures for some heart patients to prevent a heart infection caused by bacteria around the teeth, according to a new American Heart Association (AHA) scientific statement published today in the Association’s flagship journal, Circulation.
Infective endocarditis (IE), also called bacterial endocarditis, is a heart infection caused by bacteria that enter the bloodstream and settle in the heart lining, a heart valve or a blood vessel. Viridans group streptococcal infective endocarditis (VGS IE) is caused by bacteria that collect in plaque on the tooth surface and cause inflammation and swelling of the gums. There’s been concern that certain dental procedures may increase the risk of developing VGS IE in vulnerable patients.
The new guidance affirms previous recommendations that only four categories of heart patients should be prescribed antibiotics prior to certain dental procedures to prevent VGS IE due to their higher risk for complications from the infection:
It has been over a decade since recommendations for preventing IE were updated amid concerns of antibiotic resistance due to overprescribing. The AHA’s 2007 guidelines more tightly defined which patients should receive preventive antibiotics before certain dental procedures to the four high-risk categories. This change resulted in about 90% fewer patients requiring antibiotics.
Older adults with more harmful than healthy bacteria in their gums are more likely to have evidence for amyloid beta – a key biomarker for Alzheimer’s disease – in their cerebrospinal fluid (CSF), according to new research from the New York University College of Dentistry and Weill Cornell Medicine. However, this imbalance in oral bacteria was not associated with another Alzheimer’s biomarker called tau.
The study, published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, adds to the growing evidence of a connection between gum disease and Alzheimer’s.
Lead study author Angela Kamer said: “To our knowledge, this is the first study showing an association between the imbalanced bacterial community found under the gumline and a CSF biomarker of Alzheimer’s disease in cognitively normal older adults. The mouth is home to both harmful bacteria that promote inflammation and healthy, protective bacteria. We found that having evidence for brain amyloid was associated with increased harmful and decreased beneficial bacteria”.
The researchers studied 48 healthy, cognitively normal adults aged 65+. Participants underwent oral examinations to collect bacterial samples from under the gumline, and lumbar puncture was used to obtain CSF in order to determine the levels of amyloid beta and tau. To estimate the brain’s expression of Alzheimer’s proteins, the researchers looked for lower levels of amyloid beta (which translate to higher brain amyloid levels) and higher levels of tau (which reflect higher brain tangle accumulations) in the CSF.
The results showed that individuals with an imbalance in bacteria, with a ratio favouring harmful to healthy bacteria, were more likely to have the Alzheimer’s signature of reduced CSF amyloid levels.
A new study by scientists at Kyoto University and the University of Fukui reports that an antibody for one gene – USAG-1 – can stimulate tooth growth in mice suffering from tooth agenesis, a congenital condition. The paper was published in Science Advances.
Although the normal adult mouth has 32 teeth, about 1% of the population has more or fewer due to congenital conditions. Scientists have explored the genetic causes for cases having too many teeth as clues for regenerating teeth in adults.
According to Katsu Takahashi, one of the lead authors of the study, the fundamental molecules responsible for tooth development have already been identified: “The morphogenesis of individual teeth depends on the interactions of several molecules including BMP, or bone morphogenetic protein, and Wnt signaling”.
BMP and Wnt are involved in much more than tooth development. They modulate the growth of multiple organs and tissues. Consequently, drugs that directly affect their activity are commonly avoided, since side effects could affect the entire body.
Guessing that targeting the factors that antagonize BMP and Wnt specifically in tooth development could be safer, the team considered the gene USAG-1. The scientists therefore investigated the effects of several monoclonal antibodies for USAG-1. Monoclonal antibodies are commonly used to treat cancers, arthritis, and in vaccine development.
The study is the first to show the benefits of monoclonal antibodies on tooth regeneration and provides a new therapeutic framework for a clinical problem that can currently only be resolved with implants and other artificial measures.
Current advice from the America Dental Association tells you that if your gums bleed, make sure you are brushing and flossing twice a day because it could be a sign of gingivitis, an early stage of gum disease. So if you are concerned, see your dentist. However, a new University of Washington (UW) study suggests you should also check your intake of vitamin C.
“When you see your gums bleed… You should try to figure out why your gums are bleeding. And vitamin C deficiency is one possible reason,” said the study’s lead author Philippe Hujoel, a practising dentist and professor of oral health sciences in the UW School of Dentistry.
Hujoel’s study, published in Nutrition Reviews, analysed published studies of 15 clinical trials in six countries, involving 1,140 predominantly healthy participants, and data from 8,210 US residents surveyed in the Centers for Disease Control and Prevention’s Health and Nutrition Examination Survey. The results showed that bleeding of the gums on gentle probing, or gingival bleeding tendency, were associated with low vitamin C levels in the bloodstream. The researchers found that increasing daily intake of vitamin C in those people with low vitamin C plasma levels helped to reverse these bleeding issues.
Hujoel does recommend people attempt to keep an eye on their vitamin C intake through incorporation of non-processed foods such as kale, peppers or kiwis into their diet, and if you can’t find palatable foods rich in vitamin C, to consider a supplement of about 100-200 milligrams a day.
People with periodontitis (gum disease) are at higher risk of experiencing major cardiovascular events, according to new research from Forsyth Institute and Harvard University scientists and colleagues.
In a longitudinal study published recently in the Journal of Periodontology, Dr Thomas Van Dyke at Forsyth, Dr Ahmed Tawakol of Massachusetts General Hospital, and their collaborators showed that inflammation associated with active gum disease was predictive of arterial inflammation, which can cause heart attacks, strokes, and other dangerous manifestations of cardiovascular disease.
For the study, researchers performed positron emission tomography and computer tomography (PET and CT) scans on 304 individuals to view and quantify inflammation in the arteries and gums. In follow-up studies approximately four years later, 13 of those individuals developed major adverse cardiovascular events. Presence of periodontal inflammation was shown to be predictive of cardiovascular events, even after researchers controlled for all other risk factors, such as smoking, high blood pressure, obesity, and diabetes.
Importantly, researchers found that bone loss from prior periodontal disease was not associated with cardiovascular events. Patients that did not have actively inflamed gums had a lower risk of cardiovascular disease – even if those individuals had a prior history of periodontal disease.
Researchers hypothesise that local periodontal inflammation activates and mobilises cells signalling through bone marrow, which triggers the inflammation of arteries, leading to adverse cardiac events.
While the study sample size is relatively small, Van Dyke said the observation is significant and should be studied in a much larger population. For people with active gum disease, seeking treatment could potentially prevent a dangerous a cardiac event.
Researchers in Australia have recently received government funding for a project that aims to develop a system that would allow parents to take photographs of their children’s teeth. The photographs would then be sent to dental practitioners for evaluation. The novel system would improve access to routine dental care and reduce inappropriate or unnecessary referrals, thus helping to minimise travel and waiting times.
The project is being conducted in collaboration with the Commonwealth Scientific and Industrial Research Organisation and the Telethon Kids Institute and is being led by a group of researchers from the University of Western Australia in Perth. It is part of a line of ongoing research that has been looking at the application of consumer-level technology for facilitating access to dental care.
The 12-month project aims to develop a system for screening infants and children using smartphone images taken by untrained people. The images would be accessed by the dental team, who would then help determine whether cases require a referral or can be delayed.
“The core of the teams’ 25 years of effort is to bring access to dental health to those at the marginal edges of society,” co-researcher Dr Marc Tennant, Winthrop Professor at the School of Human Sciences at the university, told Dental Tribune International, “This access is about many facets, including cost and social and geographic factors”.
Tennant explained that the present project focuses on the oral health of children, but that the wider programme includes adults.
Bacteria often show very strong biogeography — some bacteria are abundant in specific locations while absent from others — leading to major questions when applying microbiology to therapeutics or probiotics: how did the bacteria get into the wrong place? How do we add the right bacteria into the right place when the biogeography has gotten ‘out of whack’?
These questions, though, have one big obstacle, bacteria are so tiny and numerous with very diverse and complicated populations, which creates major challenges to understanding which subgroups of bacteria live where and what genes or metabolic abilities allow them to thrive in these ‘wrong’ places.
In a new study published in Genome Biology researchers led by Harvard University examined the human oral microbiome and discovered impressive variability in bacterial subpopulations living in certain areas of the mouth.
The mouth contains a surprising amount of site-specific microbes in different areas. For instance, the microbes found on the tongue are very different from the microbes found on the plaque on teeth. Co-author A. Murat Eren said: “Your tongue microbes are more similar to those living on someone else’s tongue than they are to those living in your throat or on your gums!”
Using an approach called metapangenomics, which combines pangenomes (the sum of all genes found in a set of related bacteria) with metagenomics (the study of the total DNA coming from all bacteria in a community), allowed the researchers to conduct an in-depth examination of the genomes of the microbes, which led to a shocking discovery.
“We found a tremendous amount of variability,” said lead author, Daniel R. Utter, “But we were shocked by the patterning of that variability across the different parts of the mouth; specifically, between the tongue, cheek, and tooth surfaces”.
The human body is filled with friendly bacteria. However, some of these microorganisms, such as Veillonella parvula, may be too nice. These peaceful bacteria engage in a one-sided relationship with pathogen Porphyromonas gingivalis, helping the germ multiply and cause gum disease, according to a new University at Buffalo (UB)-led study.
The research sought to understand how P. gingivalis colonises the mouth. The pathogen is unable to produce its own growth molecules until it achieves a large population in the mouth. The answer: it borrows growth molecules from V. parvula, a common yet harmless bacteria in the mouth whose growth is not population dependent.
In a healthy mouth, P. gingivalis makes up a miniscule amount of the bacteria in the oral microbiome and cannot replicate. But if dental plaque is allowed to grow unchecked due to poor oral hygiene, V. parvula will multiply and eventually produce enough growth molecules to also spur the reproduction of P. gingivalis.
More than 47% of adults 30 and older have some form of periodontitis (also known as gum disease), according to the Centers for Disease Control and Prevention in the US. Understanding the relationship between P. gingivalis and V. parvula will help researchers create targeted therapies for periodontitis, says Patricia Diaz, DDS, PhD, lead investigator on the study and Professor of Empire Innovation in the UB School of Dental Medicine.
The study, which was published on December 28 in the ISME Journal, tested the effects of growth molecules exuded by microorganisms in the mouth on P. gingivalis.
University of Illinois Chicago (UIC) researchers captured high-resolution, real-time images of the mineralisation process in an artificial saliva model. Their discovery showed distinct pathways that support bone and teeth formation, or biomineralisation.
Reza Shahbazian-Yasser, UIC professor of mechanical and industrial engineering at the College of Engineering and corresponding author of the paper said: “The control over the dissolution of amorphous calcium phosphate affects the assembly of hydroxyapatite crystals into larger aggregates. Using technology developed at UIC, we found evidence that these pathways coexist simultaneously — explaining why different groups had reported seemingly different or opposite results. In addition, we now understood how hydroxyapatite materials nucleate and grow on amorphous calcium phosphate templates. The control over the nucleation and growth of hydroxyapatite will aid in developing new drugs and medical treatments to heal lost or broken bones faster or cure tooth cavities”.
To capture the images, the researchers used a unique micro-device that made it possible to use electron microscopy with a liquid model. Using this method, the researchers were able to monitor chemical reactions in the model on the smallest scale.
“Our study provides clear, new evidence of how minerals organise and grow into bone materials, and this finding has many important implications for further research on bone or teeth healing,” Shahbazian-Yasser said.
Medical conditions caused by dysfunctional mineralisation in the body can include everything from a tendency to develop cavities to osteoporosis.
“In the next step, we would like to learn how molecular modifiers can affect the process of biomineralisation, which is important to develop effective drugs,” Shahbazian-Yasser said.
Sharing toothbrushes and other ill-advised oral hygiene measures could play an influential role in spreading Covid-19, according to new research. The latest study showed that sharing a toothbrush, toothpaste, the same container for brushes, and not changing your brush after the viral process, are all possible routes of cross-contamination of coronavirus.
The investigation monitored hundreds of families over the course of 15 days and found over half (55%) of Covid-positive people who share a toothbrush passed the virus onto other family members in the household.
Dr Nigel Carter OBE, Chief Executive of the Oral Health Foundation, believes oral hygiene habits like sharing toothbrushes are linked to the transmission of many diseases and should be discouraged.
Dr Carter says: “There are many hundreds of different bacteria and viruses in our mouths and those sharing a toothbrush could be passing these on to others. While this might be something relatively harmless, such as a common cold or cold sore, if the person you are sharing with is infected with viruses like hepatitis B and now coronavirus, these could also be passed on via the toothbrush, with severe health consequences”.
In addition to sharing a toothbrush, the research published in BMC Oral Health, discovered an even greater risk for families leaving their toothbrushes in the same container. Two in three (66%) people who tested positive for coronavirus and who share a toothbrush container with family members passed the virus on to them. Further findings showed the same tube of toothpaste should also not be used between members of the same family.