Treating gum disease after heart rhythm ablation reduced risk of AFib recurrence

Research Highlights:

• Treating gum disease within three months after a heart procedure to correct an irregular heart rhythm, known as atrial fibrillation (AFib), may lower the chances of it reoccurring.
• Inflamed gums may predict AFib recurrence after heart ablation, a procedure to fix the irregular heartbeat.
• AFib patients should be examined for gum disease and encouraged to seek dental treatment, researchers said.

Treating gum disease in the 3-months after a procedure to correct an irregular heartbeat known as atrial fibrillation (AFib) may lower oral inflammation and may reduce AFib recurrence, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

According to the U.S. Centers for Disease Control and Prevention (CDC), about half of American adults ages 30 or older have some form of periodontal or gum disease, with the incidence increasing with age.

This study is among the first to investigate the potential impact of gum disease treatment on AFib. AFib is a condition in which the heart beats irregularly, increasing the risk of stroke by five-fold. More than 12 million people in the U.S. are expected to have AFib by 2030, according to the American Heart Association’s 2024 Heart Disease and Stroke Statistics.

“Gum disease can be modified by dental intervention. Proper management of gum disease appears to improve the prognosis of AFib, and many people around the world could benefit from it,” said lead study author Shunsuke Miyauchi, M.D., Ph.D., an assistant professor at the Health Service Center at Hiroshima University in Japan who engages in general cardiology, arrhythmia practice and research.

Researchers followed 97 patients who had undergone the non-surgical procedure to correct AFib (radiofrequency catheter ablation) and received treatment for gum inflammation along with 191 ablation patients who did not receive treatment for gum disease. Catheter ablation is a procedure that uses radiofrequency energy to destroy a small area of heart tissue causing rapid and irregular heartbeats. This study found that an index measuring the severity of gum inflammation was associated with the return of AFib.

After the ablation procedure, during the average follow-up period of between 8.5 months to 2 years, researchers found:

• AFib recurred among 24% of all participants  throughout the follow-up period.
• Patients with severe gum inflammation who had it treated after heart catheter ablation were 61% less likely to have a recurrence of AFib, compared to ablation patients who did not have treatment for severe gum inflammation.
• Patients who had recurrences of AFib had more severe gum disease than those who did not have recurrences.
• Having gum disease, being female, experiencing irregular heartbeat for more than two years and left atrial volume were predictors for AFib recurrences. Left atrial volume often leads to AFib recurrence as it includes thickening and scarring of connective tissues, Miyauchi explained.

Miyauchi noted that, “While the main findings were consistent with their expectations, we were surprised how useful a quantitative index of gum disease, known as periodontal inflamed surface area or PISA, could be in cardiovascular clinical practice.”

While the American Heart Association does not recognize oral health as a risk factor for heart disease, it recognizes that oral health can be an indicator of overall health and well-being. Bacteria from inflamed teeth and gums may travel through the bloodstream to the rest of the body, including the heart and brain. Chronic gum inflammation may be associated with other systemic health conditions, including coronary artery disease, stroke and Type 2 diabetes.

Study details and background:

• A total of 288 adults (66% men; 34% women) being treated for AFib were enrolled in this study.
• The single center study was conducted from April 1, 2020 to July 31, 2022, at Hiroshima University Hospital in Hiroshima, Japan, and all participants were Asian.
• Enrollees were examined by a dentist before undergoing catheter ablation for AFib.

“We are now working on further research to reveal the mechanism underlying the relationship between gum disease and AFib,” Miyauchi said.

The study’s limitations include: a small number of patients enrolled from a single center; patients were not randomized to receive dental treatment; periodontal status was not followed up after the initial examination among the participants who did not receive gum disease treatment; and inflammatory markers were not reassessed after the ablation procedure.

• 
  
• AHA news release: New initiative focuses on oral health clinicians in prevention and early detection of heart disease (Jan. 2024)
• AHA news release: Poor oral health may contribute to declines in brain health (Feb 2022)
• 
  
  

ChatGPT to help dental students retain knowledge and enhance performance

 I

A study aiming to utilize current dental course materials, syllabi, and textbooks to investigate ChatGPT's potential benefits for dental students. was presented at the 102nd General Session of the IADR, which was held in conjunction with the 53rd Annual Meeting of the American Association for Dental, Oral, and Craniofacial Research and the 48th Annual Meeting of the Canadian Association for Dental Research, on March 13-16, 2024, in New Orleans, LA, USA.

The abstract, “ChatGPT to Help Dental Students Retain Knowledge and Enhance Performance” was presented during the “SCADA: Clinical Science/Public Health Research” Poster Session that took place on Thursday, March 14, 2024 at 11 a.m. Central Standard Time (UTC-6).

The study, by Ihunna Amugo of Meharry Medical College, Nashville, TN, USA, conducted an extensive literature review, analyzing previous studies in different educational contexts to evaluate ChatGPT's efficacy in dental education. Questions aligned with dental course materials and objectives were formulated to ensure ChatGPT's relevance to the specific needs of dental students. The research encompassed various dental courses, including operative dentistry, nutrition, periodontics, oral radiology, and biology of disease.

By applying ChatGPT in these courses, its capabilities were harnessed to generate step-by-step instructions, summaries, and questions to supplement traditional learning methods. Data on students' interactions with ChatGPT were collected and analyzed, assessing usage patterns, engagement levels, and perceived benefits. 

The study's results indicated that ChatGPT has the potential to enhance students' understanding and knowledge retention. In addition, ChatGPT can effectively provide instructional support and generate relevant content for dental students. 

Low-cost liquid tames tooth decay

An inexpensive, cavity-fighting liquid called silver diamine fluoride (SDF) works as well as dental sealants to keep tooth decay at bay in a school cavity prevention and treatment program, according to a new study by researchers at NYU College of Dentistry. 

 

The study, which followed more than 4,000 elementary school students for four years and is published in JAMA Pediatrics, shows that SDF is an effective alternative to sealants, and can increase access to dental care while reducing costs.

 

Dental cavities are the most prevalent chronic disease in children and can lead to pain, school absences, and lower academic performance. To prevent cavities, especially among children less likely to see a dentist, the Centers for Disease Control and Prevention (CDC) supports the use of school sealant programs. In sealant programs, dental professionals visit schools to apply a thin, protective coating to the surface of teeth that hardens and safeguards against decay.

 

SDF has emerged as another promising treatment for fighting cavities. Originally approved by the FDA for treating tooth sensitivity, the solution is brushed onto the surface of teeth, killing decay-causing bacteria and remineralizing teeth to prevent further decay.

 

“A growing body of research shows that SDF—which is quicker to apply and less expensive than sealants—can prevent and arrest cavities, reducing the need for drilling and filling,” said Richard Niederman, DMD, professor of epidemiology & health promotion at NYU College of Dentistry and the study’s senior author.

 

SDF in schools

Researchers at NYU College of Dentistry led CariedAway, the nation’s largest school-based cavity prevention study, to compare the use of SDF and traditional sealants. The study included approximately 4,100 children in New York City elementary schools; more than a quarter of kids had untreated cavities at the start of the study.

 

At each school visit, a team of health professionals examined children’s teeth and applied either sealants or SDF followed by fluoride varnish, depending on which treatment the school was randomly assigned to receive. Sealants were administered by dental hygienists, while SDF was applied by either dental hygienists or registered nurses, all under the supervision of a dentist. Starting in 2018, the team visited each school twice a year, although the COVID-19 pandemic and school closures led to missed visits.

 

The researchers reported last year in the journal JAMA Network Open that a single treatment of either SDF or sealants prevented 80% of cavities and kept 50% of existing cavities from worsening two years later. The team continued their study for another two years, and in their study published in JAMA Pediatrics, found that SDF and sealants prevented roughly the same number of cavities after children were followed for a total of four years. Moreover, both sealants and SDF reduced the risk of decay at each follow-up visit.

 

“Our longitudinal study reaffirms that both sealants and SDF are effective against cavities. SDF is a promising alternative that can support school-based cavity prevention—not to replace the dental sealant model, but as another option that also prevents and arrests decay,” said Ryan Richard Ruff, PhD, MPH, associate professor of epidemiology & health promotion at NYU College of Dentistry and the study’s first author.

 

“Most research shows that SDF can stop a cavity from progressing further. Our study demonstrated that SDF can prevent cavities from happening in the first place,” said Tamarinda Barry Godín, DDS, MPH, associate program director and supervising dentist for CariedAway, research scientist at NYU College of Dentistry, and the study’s coauthor. 

 

An “untapped” oral health workforce

Embracing SDF for cavity prevention and treatment in schools could keep kids from needing fillings, saving families and the healthcare system money. Yet these programs can only succeed if there are enough health professionals to provide care.

 

The NYU researchers found that children who had SDF applied by dental hygienists and registered nurses had similar outcomes, suggesting that nurses—including school nurses—could play a crucial role in cavity prevention programs. 

 

“Nurses may be an untapped resource for addressing oral health inequities,” added Ruff. “Our results suggest that nurses can effectively provide this preventive care, which could dramatically improve access, given the role of school nurses and the size of the nursing workforce.”

Those who report having poor oral health have negative long-term health outcomes

Those who report having poor oral health are as likely to have negative long-term systemic health outcomes as those previously diagnosed with periodontal disease, or gum disease, according to a new Tufts University School of Dental Medicine study published in The Journal of the American Dental Association. 

The researchers examined whether self-reported oral health questions, which are commonly used in the surveillance of periodontal disease, had the same or similar comorbidities of the disease by analyzing data sets from the Women’s Health Study and the National Health and Nutrition Examination Survey (NHANES). The Women’s Health Study followed women 45 years or older with self-reported information on gum disease, oral health questions, cardiovascular disease, diabetes, and osteoporosis in various timeframes starting from 1992, while the NHANES included data on oral health questions and linked mortality from 1999 to 2018. 

Led by first author Yau-Hua Yu, associate professor of periodontology at the School of Dental Medicine, the researchers tested their hypotheses by running analyses that estimated the probability of outcomes based on a variety of factors and then looked at survival rates within various groups. The results showed that negative self-evaluations were associated with the same level of systemic comorbidities as those who had been diagnosed with periodontal disease. The study also found that suboptimal dental visits or infrequent flossing were associated with an increase in all-cause mortality.  

“These questions are really helpful to understand a person’s oral health conditions when clinical access is limited,” said Yu, noting that in large epidemiological studies like the Women’s Health Study, it’s not possible to have a dentist on-site to physically examine research participants.

Yu and fellow researchers, including senior author Julie Buring of Brigham and Women’s Hospital and Harvard Medical School, also examined the role that access to dental care plays on overall health. They did this by asking two important questions: “In the past 12 months, have you visited the dentist or hygienist?” and “How often do you visit a dental office for routine check-ups and cleaning?” The researchers found that about 10% of the Women’s Health Study participants and 45% of NHANES study participants did not visit a dentist within a year and, as a result, their oral and overall health outcomes were poor.  

“Our study findings suggest that people who don’t see a dentist may have negative outcomes in terms of mortality,” Yu said, noting that their original goal was to understand the usefulness of these questions for understanding and evaluating gum disease and oral health in general.

Given this demonstrated link between oral health and mortality, Yu suggests primary care physicians consider asking about their patients’ dental habits and condition to get a fuller picture of their overall health.

Yu isn’t stopping with this study. She says she’s still working on big data sets, and hopes to showcase outcomes in different populations, such as veterans. She is currently collaborating with the U.S. Department of Veterans Affairs. 

And, Yu underscores the need for more large-scale national health studies/biobanking efforts to incorporate questions around dental health to better understand and communicate the association between oral health and long-term health outcomes, as well as the gaps in access to dental care.  

“For society in general,” she said, “we need to look at, without dental care access, what is the burden?”

‘Artificial tongue’ detects and inactivates common mouth bacteria

 

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

From the fuzzy feeling on your teeth to the unfortunate condition of halitosis, bacteria shape mouth health. When dental illnesses take hold, diagnosis and treatment is necessary, but identifying the microorganisms behind an infection can be a lengthy and expensive process. Now, researchers reporting in ACS Applied Materials & Interfaces have designed a chemical sensor array, or an artificial tongue, that distinguishes dental bacteria and can inactivate them.

When bacteria are suspected as the agent behind dental disease, such as cavities or periodontitis, the first step is to identify the source. Traditional detection and identification methods can involve culturing or looking for specific DNA markers belonging to different species using sophisticated equipment. So, Na Lu, Zisheng Tang and coworkers wanted to investigate a simple and less expensive alternative: sensor arrays known as electronic or artificial tongues. Previously developed artificial tongues have detected and measured several types of bacteria, similar to how a real tongue can taste multiple flavors at once. And the researchers wanted to add in the capability of reducing the effects of, or inactivating, the identified dental bacteria.

The researchers turned to a nanoscopic particle that mimics natural enzymes, called a nanozyme, and made them from iron oxide particles coated in DNA strands. When hydrogen peroxide and a colorless indicator were added in solution, the presence of nanozymes caused the indicator to turn bright blue. However, bacteria that adhered to the DNA decreased the nanozyme’s reactivity, reducing the amount of blue color produced. The researchers coated nanozymes with different DNA strands so that each type of bacteria could be linked to a unique change in color signals. To test the DNA-nanozyme system, as an artificial tongue, the researchers created samples of 11 different dental bacteria species. The sensor array was able to identify all the bacteria in artificial saliva samples. Then, using the DNA-encoded nanozyme sensor array, the researchers were able to distinguish whether a dental plaque sample came from a healthy volunteer or from a person with cavities.

In addition, the DNA-encoded nanozyme sensor array had antibacterial effects on the dental bacteria species tested. Compared to controls without the nanozymes, three typical bacterial species were inactivated in solutions containing the nanozyme system. Scanning electronic microscopic images suggest to the researchers that the nanozyme system destroyed the bacteria membranes. They suggest that this sensor system could also be used in the future to diagnose and treat bacterial dental diseases.

When it comes to bad breath, some bacterial interactions really stink

 

Researchers from Osaka University find that a metabolite produced by the commensal oral bacterium Streptococcus gordonii activates another bacterial species, Fusobacterium nucleatum, to produce the malodorous compound methyl mercaptan

Peer-Reviewed Publication

OSAKA UNIVERSITY

 

IMAGE: 

SCHEMATIC REPRESENTATION OF OBSERVED METABOLIC FLOW OF BACTERIAL METABOLISM F. NUCLEATUM AND S. GORDONII COCULTURES.

view more 

CREDIT: © 2024 HARA ET AL. THIS IS AN OPEN-ACCESS ARTICLE DISTRIBUTED UNDER THE TERMS OF THE CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL LICENSE.

Osaka, Japan – Having bad breath really stinks! Now, researchers from Japan report that a particular combination of bacteria in our mouths may be responsible for producing some very unpleasant smells.

In a study published last month in mSystems, researchers from Osaka University revealed that the interaction between two common types of oral bacteria leads to the production of a chemical compound that is a major cause of smelly breath.

Bad breath is caused by volatile compounds that are produced when bacteria in the mouth digest substances like blood and food particles. One of the smelliest of these compounds is methyl mercaptan (CH3SH), which is produced by microbes that live around the teeth and on the surface of the tongue. However, little is known about which specific bacterial species are involved in this process.

“Most previous studies investigating CH3SH-producing oral bacteria have used isolated enzymes or relatively small culture volumes,” explains lead author of the study Takeshi Hara. “In this study, we aimed to create a more realistic environment in which to investigate CH3SH production by major oral bacteria.”

To do this, the researchers developed a large-volume anaerobic co-culture system that enabled them to test interactions between multiple different types of bacteria that live in the mouth. This system was able to test both direct, physical interactions among the bacteria, as well as whether these species could affect each other from a distance, for example by secreting active substances.

“The results were very intriguing,” says Masae Kuboniwa, senior author. “We found that Fusobacterium nucleatum produces large quantities of CH3SH in response to Streptococcus gordonii, another oral bacterium.”

By using stable isotope tracers and analyzing gene expression, the researchers showed that S. gordonii releases a substance called ornithine that prompts F. nucleatum to produce more of a molecule called polyamine. Because F. nucleatum needs methionine to produce polyamine, this enhanced polyamine production activates its methionine salvage pathway, which in turn results in increased CH3SH production.

“Taken together, these findings suggest that CH3SH production in the mouth is driven by the interaction between S. gordonii and F. nucleatum,” says Hara.

Understanding how these two bacterial species work together to cause bad breath could be helpful in developing ways to treat or even prevent bad breath. In addition, given that bad breath is often associated with periodontal disease, treating this symptom early could help prevent more serious damage in the future.

###

The article, “Interspecies metabolite transfer fuels methionine metabolism of Fusobacterium nucleatum to stimulate volatile methyl mercaptan production,” was published in mSystems at DOI: https://doi.org/10.1128/msystems.00764-23

Gargling away the bad bacteria in type 2 diabetes

 

Researchers from Osaka University find that gargling with an antiseptic mouthwash can reduce ‘bad’ bacteria in the mouths of people with type 2 diabetes, and may lead to better control of their blood sugar

Peer-Reviewed Publication

OSAKA UNIVERSITY

 

IMAGE: 

MECHANISM OF TYPE 2 DIABETES MELLITUS IMPROVEMENT BY GARGLING WITH MOUTHWASH

view more 

CREDIT: SAAYA MATAYOSHI

Osaka, Japan – More than bad breath, there is growing evidence that ongoing inflammation in the mouth, like with gum disease, is associated with serious diseases such as Alzheimer’s disease or type 2 diabetes. Now, researchers from Osaka University have identified an easy way to fight bacteria that might cause such problems.

In a study published this month in Scientific Reports, the researchers reported that when people with type 2 diabetes gargled with an antiseptic mouthwash, the numbers of periodontitis-related bacteria decreased. Excitingly, some patients with reduced bacteria also achieved much better control of their blood sugar, hinting at promising future clinical applications. 

“There are three highly virulent bacterial species that are linked to periodontitis, or diseases of the tissues surrounding the teeth,” explains lead author of the study Saaya Matayoshi. “We decided to see if we could reduce these three species—Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia—in patients with type 2 diabetes using a mouthwash containing the antiseptic chlorhexidine gluconate.”

To do this, the researchers took monthly or bimonthly saliva and blood samples from 173 patients over an entire year. With the saliva, the researchers noted the presence or absence of the three bacterial species, and with the blood samples, they measured HbA1c levels as a marker of blood-sugar control. Importantly, for the first 6 months of the study, the patients gargled with water, whereas for the second 6 months they gargled with the antiseptic mouthwash. In this way, the research team could see whether gargling itself was effective for reducing bacteria, or whether mouthwash was more effective.

“We were unsurprised to see that gargling with water had no effects on bacterial species or HbA1c levels,” explains Kazuhiko Nakano, senior author of the study. “However, there was an overall reduction in bacterial species when the patients switched to mouthwash, as long as they were gargling at least twice a day.”

The researchers also found that, although there were no overall changes in HbA1c levels when patients gargled with the antiseptic mouthwash, there appeared to be large variations in individual responses. For example, when they split the group into younger and older patients, younger patients had greater reductions in bacterial species and significantly better blood-sugar control with the mouthwash compared with water.

Given that poor oral health is linked to serious disease, simple methods to improve oral hygiene have important ramifications. If researchers can identify patients who are likely to respond well to antiseptic mouthwash, this easy-to-use treatment may improve the lives of people with periodontitis-linked diseases such as diabetes, dementia, cardiovascular disease, and respiratory tract infections.