Root canal treatment reduces heart disease and diabetes risk

 

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Root canal infections can cause bacteria to enter the blood, leading to inflammation, heart disease and diabetes risk. Successful treatment reduces these risks

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King's College London

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Successful root canal treatment could reduce inflammation linked to heart disease and improve levels of blood sugar and cholesterol

Peer-Reviewed Publication

King's College London

 

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Root canal infections can cause bacteria to enter the blood, leading to inflammation, heart disease and diabetes risk. Successful treatment reduces these risks

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Credit: King's College London

Successful root canal treatment could reduce inflammation linked to heart disease and improve levels of blood sugar and cholesterol.

In the first of its kind research, a clinical study by King’s College London tracked changes in blood chemistry following root canal treatment for a common dental infection (apical periodontitis). The infection can cause bacteria to enter the bloodstream and increase inflammation, associated with risks to cardiac health and reduced ability to control blood sugar levels.

Despite the link between the infection and wider health impacts, the association between successful root canal treatment and the benefits to heart and metabolic health had not been investigated until now.

The team discovered that successful root canal treatment was associated with:

• Improved glucose metabolism: Blood sugar levels dropped significantly over two years after treatment, a key factor in preventing diabetes
• Better lipid profiles: Short-term improvements in blood cholesterol and fatty acid levels, which are closely linked to heart health
• Reduced inflammation: Key markers of inflammation, often linked to cardiovascular risk and other chronic conditions, decreased over time
• Oral bacteria linked to body-wide effects: Bacteria from infected teeth were associated with changes in the body’s overall metabolism

 

Root canal infections can cause bacteria to enter the blood, leading to inflammation, heart disease and diabetes risk. Successful treatment reduces these risks

The study followed the health of 65 patients from Guy's and St Thomas' NHS Foundation Trust over two years after root canal treatment. Scientists analysed molecules in the blood of patients to reveal how the body processes sugar, fat, other key substances, and responds to disease and treatment. They used a technique known as nuclear magnetic resonance (NMR) spectroscopy, used to analyse proteins in the body.

The findings suggest that monitoring blood metabolic markers, such as glucose, fats known as triglycerides, and the protein tryptophan, could help assess recovery and risk after dental treatment.

Lead Author Dr Sadia Niazi, Senior Clinical Lecturer in Endodontology, King’s College London, said: “Our findings show that root canal treatment doesn’t just improve oral health – it may also help reduce the risk of serious health conditions like diabetes and heart disease. It’s a powerful reminder that oral health is deeply connected to overall health.

“Long-standing root canal infections can allow bacteria to enter the bloodstream, trigger inflammation, and increase blood glucose and fats levels – raising the risk of serious health issues like heart disease and diabetes. It is vital that dental professionals recognise the wider impact of these root canal infections and advocate for early diagnosis and treatment.

“We also need to move towards integrated care, where dentists and general practitioners work together to monitor the risks through these blood markers and protect overall health. It’s time to move beyond the tooth and embrace a truly holistic approach to dental care.”

While more research is needed to confirm these effects in larger populations, the study opens exciting new doors for understanding how oral care can support general health and wellbeing.

This study is published in Journal of Translational Medicine.

Notes to Editors

Funding

This study was funded by Royal College of Surgeons (RCS) England.

Images – credit King’s College London

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Journal

Journal of Translational Medicine

Teeth of babies of stressed mothers come out earlier, suggests study

 

Infants of mothers with high levels of stress hormone age faster and typically have more teeth by six months of age

Peer-Reviewed Publication

Frontiers

Children have 20 milk teeth, 10 in each jaw. This set of teeth is important for chewing and speaking, and helps to keep space open for the subsequent set of 32 permanent teeth. Milk teeth begin to develop in the womb around the sixth week of gestation, and gradually come out ('erupt') between six months and three years after birth. However, there is considerable variation in this timing, due to genetics, geography, and an infant's overall health and nutritional status. Now, researchers from the US have shown for the first time that another factor can speed up the timing of teeth eruption: maternal stress during pregnancy. The results are published in Frontiers in Oral Health.

"Here we show that a mother's higher levels of stress-related hormones, particularly of cortisol, during late pregnancy are associated with the earlier eruption of primary teeth in her infant," said corresponding author Dr Ying Meng, an associate professor at the School of Nursing of the University of Rochester in the US.

Teething problems

Meng and colleagues studied a cohort of 142 mothers in the US from socioeconomically disadvantaged backgrounds, who were pregnant between 2017 and 2022 and enrolled through the University of Rochester's Medical Center. In the late 2nd and 3rd trimesters of pregnancy, each woman gave a saliva sample, in which the concentration of the hormones cortisol, estradiol, progesterone, testosterone, triiodothyronine, and thyroxine was measured.

All children in the study were born at full term. At one, two, four, six, 12, 18, and 24 months after birth, each mother-child pair visited the clinic, where dentists assessed which milk teeth had erupted.

About half (53%) of the mothers were employed, and 60% had a high school education or lower. For the majority (76%), the present child was not their first, while a majority (59%) did not breastfeed at six months after delivery. Approximately half (52%) of the children were African-American.

By six and 12 months of age, respectively, 15% had between one and six erupted teeth while 97.5% had between one and 12. All children had some erupted teeth – between three and 20 – by age 18 months, while by 24 months, 25% of children possessed all 20 of them. In 2.7% of children, a sudden spurt occurred between 12 and 18 months, while the remainder of the children showed a more continuous pattern of eruption. But even in the latter, the pattern of eruption was inconsistent and irregular, so that a child's number of teeth at the earliest visits did not predict the number at later visits.

During pregnancy, 36.6% of the women had a diagnosis of depression or anxiety, but such a diagnosis was not associated with their hormone levels or their children's number of erupted teeth at any time-point. Hormone concentrations depended strongly on the mother: women tended to either have higher- or lower-than-average concentrations across all six of the studied hormones simultaneously.

Growing pains

Importantly, women with higher levels of the stress hormone cortisol in their saliva had offspring with a greater number of erupted teeth by six months of age. In this way, infants of mothers with the highest level of cortisol had on average four teeth more at this age than infants of mothers with the lowest cortisol levels.

"High maternal cortisol during late pregnancy may alter fetal growth and mineral metabolism, including the regulation of levels of calcium and vitamin D – both essential for mineralization of bone and teeth. Cortisol is also known to influence the activity of so-called osteoblast and osteoclast cells, responsible for building up, shaping, and remodeling bone," said Meng.

"These results are further evidence that prenatal stress can speed up biological aging in children. Premature eruption of teeth could thus serve as an early warning sign of an infant's compromised oral development and overall health, associated with socioeconomic deprivation and prenatal stress."

The authors also found an association between a mother's level of the sex hormones estradiol and testosterone and a greater number of erupted teeth in her child at 12 months after birth, but this link appeared to be weaker. Similar weak yet statistically significant positive associations were found between a mother's level of progesterone and testosterone and her child's number of teeth at 24 months, and between her level of the thyroid hormone triiodothyronine and the child's number of teeth at 18 and 24 months.

Estradiol, progesterone, and testosterone are known to play important roles in fetal development and birthweight, which is how high levels of these hormones might speed up tooth eruption.

"We still have key questions that need answering, for example which maternal hormones or downstream developmental pathways drive the change in the timing of tooth eruption, what the exact relationship is between accelerated eruption of teeth and biological aging and development, and what such speeding up says about a child's general health," said Meng.

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Journal

Frontiers in Oral Health

DOI

10.3389/froh.2025.1663817 

New study reveals key role of inflammasome in male-biased periodontitis

A study out of the University of North Carolina at Chapel Hill has unveiled new insights into the inflammatory processes behind periodontitis, a common and debilitating gum disease. Research conducted by UNC Adams School of Dentistry’s Julie Marchesan, DDS, PhD, and UNC School of Medicine’s Jenny Y. Ting, PhD, found that a part of the immune system called the inflammasome plays a key role in disease development, and that blocking this system prevents bone resorption only in males.

The study, published in the journal Proceedings of the National Academy of Sciences, suggests developing treatments specifically for male patients can have benefits and prompted an exploration of different biological mechanisms responsible for bone loss in females.

Periodontitis, inflammation-driven bone loss around the teeth, affects millions of people worldwide. While the disease is common across genders, it disproportionately impacts men, with males experiencing more severe symptoms.

“Our paradigm-shifting work not only pinpoints the inflammasome as a causal driver of male-biased periodontitis but also demonstrates a clear path for the development of sex-stratified therapeutics in periodontics,” Marchesan said. “Prior to this work, the inflammasome was believed to have the same role in the development of inflammatory conditions in both females and males. Our findings will foster the development of therapies that target the inflammasome and can specifically benefit male patients, while also paving the way for the discovery of biological mechanisms responsible for periodontitis in females.”

The study analyzed more than 6,200 human samples across three independent studies. Its findings showed that males exhibit significantly higher levels of interleukin-1 beta (IL-1β) in the gingival crevicular fluid during both healthy and periodontitis-affected states. This finding suggests that males may be more susceptible to inflammation-driven bone loss due to heightened IL-1β activity.

To further investigate this, the research team used mouse models and found male mice displayed greater IL-1β secretion than females. In addition, male mice with inflammasome gene deletions showed reduced bone loss. Applying a pharmacologic caspase-1/4 inhibitor to block inflammasome activity led to a significant reduction in inflammatory cell infiltration and a decrease in osteoclastogenesis signaling, which contributes to bone resorption. This intervention was effective in male mice but did not impact female mice, suggesting that the inflammasome’s role in periodontitis is gender-specific.

Researchers also tested male and female mice with their testes and ovaries removed, and found that male mice lost their response to caspase-1/4 inhibition. The female mice showed no change in their lack of response, further supporting the idea that the male reproductive system plays a crucial role in inflammasome-driven inflammation.

The study highlights the need for sex-specific research to fully understand the mechanisms behind inflammatory diseases. Given the prominent role of the inflammasome in driving male-biased periodontitis, further investigation into inflammasome-targeted treatments may offer a new avenue for improved patient care.

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.250709212 

Decision on dental amalgam secures an equity-focused, patient-centred approach

 

 A landmark decision was reached at the Sixth Conference of the Parties (COP6) to the Minamata Convention on Mercury, where Parties agreed to set 2034 as the global phase-out date after which the manufacture, import, or export of dental amalgam will no longer be permitted. This milestone marks a major win for oral and public health and underscores the power of unified, science-based advocacy led by FDI World Dental Federation (FDI) and the International Association for Dental, Oral, and Craniofacial Research (IADR).

The final decision reflects a balanced and equity-focused approach to phasing down dental amalgam use worldwide. Crucially, it includes a key exemption that supports the joint advocacy by FDI and IADR, which ensures that even after phase-out of dental amalgam it can be used “when its use is considered necessary by the dental practitioner based on the needs of the patient.” This provision ensures that patient care remains at the center of decision-making, safeguarding access to essential restorative treatments where alternatives are not yet available or viable.

FDI and IADR, with the support of the International Dental Manufacturers Association (IDM) and the American Dental Association (ADA), worked tirelessly to secure a balanced outcome by actively engaging in and influencing discussions throughout the negotiations. Coordinated advocacy efforts emphasized that while accelerating the phase down and eventually phasing out dental amalgam is essential, it must be achieved through an evidence-based, patient-centered, and equitable transition that is fair to all countries and considers their specific challenges and capacities.

“As we move toward the eventual phase-out of dental amalgam, it is essential that the needs of our members, and the patients they serve, remain at the heart of every decision,” said Mr Enzo Bondioni, Executive Director of FDI. “This outcome provides much-needed time and clarity for our members to plan, prepare, and implement the necessary national policies. It reinforces FDI’s commitment to supporting the global dental community in maintaining continuity of care and advancing oral health equity during this important transition”.

Over four days of intense deliberation, both organizations delivered individual and joint statements reinforcing the continued relevance of dental amalgam in restorative dentistry, while emphasizing the importance of prevention. They called for research into affordable, effective, and sustainable alternative materials and emphasized that waste management should be compulsory to reinforce the Convention’s broader objective of reducing environmental mercury exposure. These concerted efforts helped ensure that the final phase-out timeline was extended beyond 2030, the date originally proposed to 2034.

“Science and evidence must remain at the heart of every global health policy decision,” said Dr Christopher Fox, Chief Executive Officer of IADR. “This outcome reflects the progress we’ve made by investing in research into mercury-free alternatives, as called for in the text of the Minamata Convention, from both the public and private sectors. “IADR remains committed to supporting continued innovation and research that will further the rapid improvement of affordable, effective, and sustainable restorative materials, so no one is left behind in this transition”.

The decision gives Parties nine years to adapt their national strategies and healthcare systems to this new framework. This aligns closely with FDI and IADR’s long-standing position advocating for a coordinated and equity-focused phase-down that allows all countries, especially low- and middle-income nations, to strengthen capacity, build technical expertise, and ensure continuity of patient care during the transition.

By recognizing the diverse realities of healthcare delivery worldwide, the 2034 phase-out date and practitioner-based exemption together provide flexibility that avoids widening existing oral health inequalities. The Minamata Convention on Mercury, which entered into force in August 2017, now counts 153 Parties as of September 2025. The Seventh Conference of the Parties (COP7) will take place in June 2027, coinciding with the tenth anniversary of the Convention.

About FDI World Dental Federation (FDI)

FDI World Dental Federation is the leading global voice of the dental profession and envisions a world with optimal oral health. It serves as the principal representative body for over 1 million dentists worldwide. Its membership includes some 200 national dental associations and specialist groups in over 130 countries. www.fdiworlddental.org/

About International Association for Dental, Oral, and Craniofacial Research (IADR)

The International Association for Dental, Oral, and Craniofacial Research (IADR) is a nonprofit organization with a mission to drive dental, oral, and craniofacial research for health and well-being worldwide. IADR represents the individual scientists, clinician-scientists, dental professionals, and students based in academic, government, non-profit, and private-sector institutions who share our mission. Learn more at www.iadr.org.

Non-prescription pain meds work equally well for men and women after tooth extraction

 

Over-the-counter pain medications work as well or better than opioids after wisdom tooth extraction for both men and women, according to a Rutgers Health-led follow-up to a landmark paper on comparative pain relief.

That first paper on the collective experience of more than 1,800 trial patients found that the combination of ibuprofen and acetaminophen provided better pain relief than hydrocodone with acetaminophen for the first two days after surgery and greater satisfaction over the post-operative period. The new subgroup analysis, published in JAMA Network Open, demonstrated that the results held for both male and female patients.

"We wanted to determine whether the pain medication’s effects were consistent in males and females separately," said Janine Fredericks Younger, an associate professor at Rutgers School of Dental Medicine and lead author of the analysis. "And what we found is that in both subgroups (males and females), the non-opioid was superior for that first day and night, and then no worse than the opioid for the rest of the post-op period."

The trial that produced both papers, funded by an $11 million grant from the National Institutes of Health, compared patients who received 400 milligrams of ibuprofen (Advil, Motrin) combined with 500 milligrams of acetaminophen (Tylenol) against those who got 5 milligrams of hydrocodone with acetaminophen. 

The gender-specific analysis was particularly important because women consistently report higher pain levels after surgery, raising questions about whether pain medications work differently for each sex. 

"There's obviously different biological mechanisms, different hormones involved," said Cecile Feldman, dean of Rutgers School of Dental Medicine and senior author of both studies. "But results confirm that the analgesic effect for both groups is the same."

The researchers deliberately enrolled equal numbers of men and women from the start, allowing them to conduct robust subgroup analyses. Patients across five universities tracked their pain twice daily for nine days using electronic diaries, rating not just pain but also sleep quality, ability to perform daily activities and overall satisfaction.

On every measure, the over-the-counter combination matched or beat the opioid. Patients taking the non-opioid medications reported better sleep quality and less interference with daily activities. Those who received opioids were twice as likely to call back requesting additional pain medication.

"The results actually came in even stronger than we thought they would," Feldman said. "We expected to find the non-opioid to be non-inferior, so that at least it was no worse than opioids. We were surprised to see that it was actually superior."

Dental procedures are a common entry point for opioid exposure. Dentists wrote more than 8.9 million opioid prescriptions in 2022, ranking among the nation's leading prescribers of the drugs.

"There are studies out there to show that when young people get introduced to opioids, as many have via wisdom tooth extraction, there's an increased likelihood that they'll eventually use them again, and then it can lead to addiction," said Fredericks Younger, noting that opioid overdoses kill more than 80,000 Americans annually.

The research focused on the extraction of impacted wisdom teeth, which requires cutting into gums and sometimes removing bone, making it one of the most painful dental procedures. The Food and Drug Administration uses this as a standard model for testing pain medications because it reliably produces moderate to severe pain for about 48 hours.

Feldman said the results, showing the superiority of the over-the-counter medication to opioids, likely apply to other dental procedures but cannot be automatically generalized to surgeries in other parts of the body. She would like to see similar studies conducted for a range of procedures, particularly those for orthopedic injuries, which frequently result in opioid prescriptions for high school and college athletes.

Despite mounting evidence, many dentists continue writing "just in case" opioid prescriptions for patients who are told to start with over-the-counter medications. The next phase of research will examine why these prescribing patterns persist.

"How can we now, with the evidence and the knowledge that we have, eliminate these prescriptions from being written?" Fredericks Younger said.

The findings align with American Dental Association recommendations to avoid opioids as first-line pain treatment. Feldman said the study's results leave little room for doubt.

"We feel pretty confident in saying that opioids should not be prescribed routinely for dental procedures," she said. "Our non-opioid combination really should be the analgesic choice."

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Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2025.42467 

Scientists find cells that know when, where, and how to grow teeth

 Tooth development is a dynamic process that involves the stages of the bud, the cap, and the bell, followed by root development and subsequent tooth formation. Processes such as the bud-to-cap transition are mediated by epithelial-mesenchymal interactions. In addition, the position of a cell in a developing embryo determines its fate due to the relative differences in concentration of signaling molecules and growth factors.

Scientists have long known that a single tooth develops as a small bud of outer “epithelial” cells into the deeper “mesenchymal” cells. It then curves to form a cap shape and then folds in further to form the bell shape of a mature tooth, with surrounding bone and gums. Dr. Han-Sung Jung and his team at the Yonsei University College of Dentistry, Korea, extended these findings by examining how the position of young epithelial and mesenchymal dental cells would influence what they grow into and have published their findings in International Journal of Oral Science.

Lead author Dr. Jung said that his team “performed this study to identify how positional identity along the lingual-buccal axis determines distinct developmental fates of dental mesenchyme. This research has the potential to significantly impact our understanding of tooth development,” he says.

The investigators separated the mesenchymal cells on the lingual and buccal sides at both cap and bell stages of a developing mouse embryo and -compared their gene expression profiles through RNA-seq followed by Gene Ontology enrichment analysis to understand the differences with position and time. They then transplanted the cap-stage lingual and buccal cells separately under the kidney capsule of immunocompromised mice to see what each grew into. Analysis showed that cells on the lingual side were mainly geared toward making the tooth itself and shaping its structure, while cells on the buccal side were more focused on stem cell activity, forming surrounding tissues, and supporting tooth growth and repair. Not surprisingly, only the lingual cells in the mouse kidney grew into tooth enamel.

The researchers also reported haphazardly mixing up cap-stage, tagged buccal and lingual cells of genetically engineered mice. “We were curious to know if they could find their original place and reorganize when the fluorescently labled lingual and buccal mesenchymal cells were mixed randomly, which they not only did, but the lingual cells grew into dentin to form the tooth as before. This phenomenon is called cellular self-organization,” says first author Eun-Jung Kim.

Furthermore, they have extensively studied the signalling molecules in each group and found that WNT signalling and R-spondins (Rspo1/2/4) are enriched in lingual cells, along with high proliferation, low cell death, and higher migration rate, aiding tooth formation. On the other hand, buccal cells show increased expression of  BMP inhibitors, lower proliferation, higher apoptosis, and slower migration, favoring bone and surrounding tissue formation.

In conclusion, the authors proposed a model of dental cell positioning based on the lingual-buccal axis for tooth and surrounding tissue formation. The characteristics of dental mesenchymal cells were found to vary along this axis, and the fate of the tooth and surrounding tissue formation is determined by mesenchymal cells via WNT/BMP signaling. Deeper knowledge of the molecular nuances of tooth development will inspire further research in tissue engineering and regenerative medicine, which may ultimately lead to advancements in stem cell-based tooth regeneration and more effective therapeutic applications for dental restoration and repair.

 

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Reference
DOI: https://doi.org/10.1038/s41368-025-00391-7

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Journal

Gum disease and cavities linked to increased stroke risk

 

Highlights:

• A new study finds that having both gum disease and cavities is linked to an 86% increased risk of stroke compared to having a healthy mouth.
• Poor oral health was tied to a 36% higher risk of heart attacks and other cardiovascular events.
• People with regular dental visits were 81% less likely to have both gum disease and cavities.
• Researchers say improving oral health could be an important — and often overlooked — way to help reduce stroke risk.

MINNEAPOLIS – People with both cavities and gum disease may face a higher risk of ischemic stroke, according to a study published on October 22, 2025, in Neurology® Open Access, an official journal of the American Academy of Neurology. The study does not prove that poor oral health causes strokes; it only shows an association.

Ischemic strokes are the most common type of stroke and occur when a clot or blockage reduces blood flow to the brain, depriving it of oxygen and nutrients.

Cavities are holes in the tooth enamel caused by sugary or starchy foods or factors such as poor oral hygiene or genetics. Gum disease, usually caused by poor oral hygiene, is an inflammation or infection of the gums and jawbone. It can lead to tooth loss.

“We found that people with both cavities and gum disease had almost twice the risk of stroke when compared to people with good oral health, even after controlling for cardiovascular risk factors,” said study author Souvik Sen, MD, MS, MPH, of the University of South Carolina in Columbia. “These findings suggest that improving oral health may be an important part of stroke prevention efforts.”

Researchers analyzed data from 5,986 adults with an average age of 63 who had no prior history of stroke at the start of the study. All participants completed dental exams that assessed whether participants had gum disease, cavities or both. Participants were then placed in three groups: having a healthy mouth, gum disease only or gum disease with cavities.

Researchers followed them for two decades, using phone visits and medical records to determine which people had a stroke.

Of 1,640 people with healthy mouths, 4% had a stroke, of 3,151 people with gum disease only, 7% had a stroke and of 1,195 people with gum disease and cavities, 10% had a stroke.

After adjusting for factors such as age, body mass index and smoking status, researchers found when compared to people with healthy mouths, those with both gum disease and cavities had an 86% higher risk of stroke. Those with gum disease alone had a 44% increased risk.

The study also looked more broadly and found that people with both gum disease and cavities had a 36% higher risk of experiencing a major cardiovascular event, such as a heart attack, fatal heart disease or stroke when compared to people with healthy mouths.

Participants who reported visiting the dentist regularly had 81% lower odds of having both gum disease and cavities and 29% lower odds of having gum disease alone.

“This study reinforces the idea that taking care of your teeth and gums isn’t just about your smile; it could help protect your brain,” said Sen. “People with signs of gum disease or cavities should seek treatment not just to preserve their teeth, but potentially to reduce stroke risk.”

A limitation of the study is that participants’ oral health was assessed only once at the start of the study, so changes in dental health over time weren’t captured. It’s also possible that other unmeasured health factors contributed to the findings.