Category: Dentistry

Macrophages are Involved in the Aggravation of Rheumatoid Arthritis by Oral Bacteria

Photo by Caroline Lm on Unsplash

Researchers from Japan have discovered a certain oral bacteria associated with rheumatoid arthritis causes inflammation, through macrophages and an inflammatory enzyme, caspase-11. Their results appear in the International Journal of Oral Science.

Periodontal disease, which affects the gums and tissues that surround the teeth, is one of the most prevalent dental conditions worldwide, and besides tooth loss is associated with other health effects. Over the past few decades, clinical studies have revealed that the periodontal pathogen Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is closely related to the onset and worsening of rheumatoid arthritis (RA), a serious autoimmune disease that affects joints. However, what goes down at the molecular level remains largely unexplored and unclear. 

In this study, a research team from Tokyo Medical and Dental University (TMDU) in Japan sought to fill this knowledge gap through detailed mechanistic studies in an animal model. 

First, the researchers conducted preliminary experiments to confirm whether A. actinomycetemcomitans infection influenced arthritis in mice. To this end, they used the collagen antibody-induced arthritis mouse model, which is a well-established experimental model that mimics several aspects of RA in humans. They found that infection with this specific bacterium led to increased limb swelling, cellular infiltration into the lining of the joints, and higher levels of the inflammatory cytokine interleukin-1β (IL-1β) within the limbs. 

Notably, these symptoms of worsening RA could be suppressed by administering a chemical agent called clodronate that depletes macrophages. This demonstrated that macrophages were somehow involved in aggravating RA caused by A. actinomycetemcomitans infection.

Further investigation using macrophages derived from mouse bone marrow revealed that A. actinomycetemcomitans infection increased the production of IL-1β. In turn, this triggered the activation of a multiprotein complex known as the inflammasome, which plays a key role in initiating and modulating the body’s inflammatory response to infections. 

The researchers added yet one more piece to this puzzle using caspase-11-deficient mice. In these animals, inflammasome activation due to A. actinomycetemcomitans was suppressed. Most importantly, caspase-11-deficient mice exhibited less deterioration of arthritis symptoms, hinting at the important role that caspase-11 plays in this context. “Our research findings provide new insights into the link between periodontal pathogenic bacteria and the exacerbation of arthritis through inflammasome activation, offering important information on the long-debated relationship between periodontal disease and systemic diseases,” highlights Professor Toshihiko Suzuki, one of the lead authors of the study. 

With any luck, these efforts will contribute to the development of novel therapeutic strategies to manage RA. “The findings of this research may pave the way for advances in clinical treatments for RA induced by infection with A. actinomycetemcomitans. Our suggestion to inhibit inflammasome activation could attenuate the expansion of inflammation to joints, resulting in a recovery from arthritis symptoms,” says lead author Dr Tokuju Okano. “Moreover, the outcome of our work could contribute to the development of treatment strategies for not only arthritis but also other systemic diseases, such as Alzheimer’s disease, which is also related to periodontal pathogenic bacteria,” he predicts. 

Source: Tokyo Medical and Dental University

Can Toothbrushing Reduce Rates of Hospital-acquired Pneumonia?

Photo by Towfiqu barbhuiya: https://www.pexels.com/photo/a-toothbrush-with-toothpaste-on-a-white-surface-12065623/

A new study by investigators from Brigham and Women’s Hospital examined whether daily toothbrushing among hospitalised patients is associated with lower rates of hospital-acquired pneumonia and other outcomes. Their analysis of 15 randomised clinical trials found that hospital-acquired pneumonia rates were lower among patients who received daily toothbrushing compared to those who did not. The results were especially compelling among patients on mechanical ventilation. Their results are published in JAMA Internal Medicine.

“The signal that we see here towards lower mortality is striking – it suggests that regular toothbrushing in the hospital may save lives,” said corresponding author Michael Klompas, MD, MPH, hospital epidemiologist and an infectious disease physician in the Department of Medicine at BWH and Professor of Population Medicine at Harvard Pilgrim Health Care Institute.

“It’s rare in the world of hospital preventative medicine to find something like this that is both effective and cheap. Instead of a new device or drug, our study indicates that something as simple as brushing teeth can make a big difference.”

Hospital-acquired pneumonia occurs when bacteria in the mouth enter a patient’s airways and infect their lungs.

Patients experiencing frailty or patients with a weakened immune system are particularly susceptible to developing hospital-acquired pneumonia during their hospital stay.

However, adopting a daily toothbrushing regimen can decrease the amount of bacteria in the mouth, potentially lowering the risk of hospital-acquired pneumonia from occurring.

The team conducted a systematic review and meta-analysis to determine the association between daily toothbrushing and hospital-acquired pneumonia.

Using a variety of databases, the researchers collected and analysed randomised clinical trials from around the world that compared the effect of regular oral care with toothbrushing versus oral care without toothbrushing on the occurrence of hospital-acquired pneumonia and other outcomes.

The team’s analysis found that daily toothbrushing was associated with a significantly lower risk for hospital-acquired pneumonia and ICU mortality.

In addition, the investigators identified that toothbrushing for patients in the ICU was associated with fewer days of mechanical ventilation and a shorter length of stay in the ICU.

Most of the studies in the team’s review explored the role of a teeth-cleaning regimen in adults in the ICU.

Only two of the 15 studies included in the authors’ analysis evaluated the impact of toothbrushing in non-ventilated patients.

The researchers are hopeful that the protective effect of toothbrushing will extend to non-ICU patients but additional studies focusing on this population are needed to clarify if in fact this is the case.

“The findings from our study emphasise the importance of implementing an oral health routine that includes toothbrushing for hospitalised patients. Our hope is that our study will help catalyse policies and programs to assure that hospitalised patients regularly brush their teeth. If a patient cannot perform the task themselves, we recommend a member of the patient’s care team assist,” said Klompas.

Source: Brigham and Women’s Hospital

Opinion: We can’t Simply Close Dental Facilities during the Festive Period

Photo by Tima Miroshnichenko on Pexels

By Bulela Vava for Spotlight

On the 2nd of January 2024, Simphiwe*, needing emergency oral healthcare, turned to the Cala District Hospital in the Eastern Cape. However, she was confronted with a note on the door that read, “Dear Community Members, starting from the 18th of December 2023 to the 12th of January 2024 there is no dentist. The dentist will start working on the 15th of January 2024.”

Many such notices hang in front of oral health clinic doors, mostly where dentists work alone to respond to the myriad of emergency oral health needs within their catchment area. Having previously worked alone at a provincial government funded hospital in the rural Eastern Cape, similar notices would be placed on the door to the oral health clinic I operated, until such time as a colleague joined me at the facility.

Oral diseases affect more than 3 billion people globally, while in Africa, it affects an estimated 400 million people.

Oral diseases and conditions that affect people include trauma-related oral injuries, oral cancers, dental decay, and periodontal disease amongst others.

While dental decay remains the most common form of oral disease, untreated, it can lead to life-threatening complications. The closure of dental services at any oral health clinic may subject people to the risk of developing conditions such as Ludwig’s angina, a life-threatening condition that is linked to delayed access to care.

Fewer than 200 dentists

The Eastern Cape is predominantly a rural province, with most of the province’s 7.2 million people largely depending on public healthcare services for the majority, if not all their healthcare needs. The province employs fewer than 200 dentists, a majority of whom are concentrated in the more urban/peri-urban centres.

Cala, a rural town in the province’s Sakhisizwe Local Municipality, is home to an estimated 63 000 people and Cala District Hospital provides access to oral health services to this population. The hospital’s closed dental clinic over the festive period deprived the people of Cala of much-needed care.

It is well known that the festive period results in an increased need for emergency healthcare, including oral healthcare services. People often present with jaw fractures, tooth fractures -often a result of violence or accidents associated with an increase in alcohol consumption -, oral pain and sepsis. While the festive period may result in the increased need for managing these conditions, these are the usual conditions, amongst others, that are managed in many public oral health clinics in most provinces.

Oral health professionals, in particular dentists, are trained to manage the complete spectrum of general oral diseases and often refer to dental specialists for complex and specialised management. In a province like the Eastern Cape, characterised by a dire shortage of dental specialists, dentists are the last defence for many of the people in the province.

A significant portion of dentists in the province work alone, with limited options to manage their leave, often leaving clinics closed in their absence.

However, the closure of dental clinics without a detailed and well-communicated plan is unacceptable and places the lives of populations in danger. At times, people have been known to resort to harmful and dangerous home practices to relieve themselves of their anguish.

We need a plan

A comprehensive plan must be put in place for efficient management and referral of emergency oral healthcare cases during the festive period so that we avoid a repeat of this year’s unacceptable situation at Cala District Hospital 12 months down the line. People in need of oral health services must be made aware of where they can access such services without any delay.

Beyond this, there is a need to invest in building adequate human resource capacity for oral health in the province, to ensure that services are readily available. A mix of oral health professionals and the prioritisation of “lone dentist” clinics for community service placements should help alleviate some of the problems in the system.

It is concerning that the challenges faced in the Eastern Cape is very similar to those in other parts of the country. Fewer than 3000 dentists are working in the public healthcare sector nationwide. With such numbers it is unlikely that what happened to Simphiwe was an isolated incident. Her experience should serve as an important case study, highlighting the significant problems faced by communities and oral health professionals.

Those responsible for managing oral healthcare services in South Africa must take note and recognise that the continued deprioritisation and neglect of the population’s oral health cannot be allowed to continue.  We must work together to ensure that oral health is given the attention it deserves as a critical aspect of general health and well-being.

*Dr Vava is the President of the Public Oral Health Forum, a network of public oral health professionals striving for oral health equity, dignity and well-being for all.

Republished from Spotlight under a Creative Commons licence.

Source: Spotlight

Vikings: Terrifying Raiders With a Good Dental Plan

Photo by Gioele Fazzeri on Unsplash

The Vikings, famous as raiders who terrorised many parts of Europe, may have been quite ruthless, but their society seems to have had access to surprisingly advanced dental care for the era. A University of Gothenburg analysis of Viking Age teeth showed that although caries and toothache were widespread, there was also evidence of dental practices not too dissimilar from modern ones.

The study examined 3293 teeth from 171 individuals among the Viking Age population of Varnhem in Västergötland, Sweden.

The site is known for extensive excavations of Viking and medieval environments, including tombs where skeletons and teeth have been preserved well in favourable soil conditions.

The research team from the University of Gothenburg’s Institute of Odontology worked with an osteologist from Västergötland’s Museum. The skulls and teeth underwent clinical examinations at Gothenburg using standard dentistry tools under bright light.

A number of X-ray examinations were also performed using the same technique used in dentistry, where the patient bites down on a small square imaging plate in the mouth.

Caries and tooth loss

The results, which have been published in the journal PLOS ONE, show that 49% of the Viking population had one or more caries lesions.

Of the adults’ teeth, 13% were affected by caries – often at the roots. Children with milk teeth or a mix of milk and adult teeth, were entirely caries-free however. (Presumably sweets for the kids were not high on the Viking raiders’ lists.)

Tooth loss was also common among adults. The studied adults had lost an average of 6% of their teeth, excluding wisdom teeth, over their lifetimes. The risk of tooth loss increased with age.

The findings suggest that caries, tooth infections, and toothache were common among the Viking population in Varnhem – but the study also reveals examples of tooth care.

“There were several signs that the Vikings had modified their teeth, including evidence of using toothpicks, filing front teeth, and even dental treatment of teeth with infections,” says Carolina Bertilsson, a dentist and Associate Researcher, and the study’s first-named and corresponding author.

Not unlike today’s treatments

One sign of more sophisticated procedures was molars with filed holes, from the crown of the tooth and into the pulp, probably in order to relieve pressure and alleviate severe toothache due to infection.

“This is very exciting to see, and not unlike the dental treatments we carry out today when we drill into infected teeth. The Vikings seem to have had knowledge about teeth, but we don’t know whether they did these procedures themselves or had help.”

The filed front teeth may have been a form of identity marker. In both this and previous studies, the cases found were male.

Carolina Bertilsson continues: “This study provides new insights into Viking oral health, and indicates that teeth were important in Varnhem’s Viking culture. It also suggests that dentistry in the Viking Age was probably more sophisticated than previously thought.”

Source: University of Gothenburg

Clues from Autoimmune Disorder on Disrupted Tooth Enamel Development

Photo by Caroline Lm on Unsplash

In one of every 10 people, and in one third of children with celiac disease, the enamel coating of the teeth appears defective, failing to protect the teeth properly. As a result, teeth become more sensitive to heat, cold and sour food, and they may decay faster. In most cases, the cause of the faulty enamel production is unknown.

Now, a study by Prof Jakub Abramson and his team at the Weizmann Institute of Science, published recently in Nature, may shed light on this problem by revealing a new children’s autoimmune disorder that hinders proper tooth enamel development. The disorder is common in people with a rare genetic syndrome and in children with celiac disease. These findings could help develop strategies for early detection and prevention of the disorder.

Tooth enamel is made up primarily of mineral crystals that are gradually deposited on protein scaffolds during enamel development. Once the crystals are in place, the protein scaffold is dismantled, leaving behind a thin, exceptionally hard layer of enamel. A strange phenomenon was identified in people with a rare genetic disorder known as APS-1: although the enamel layer of their milk teeth forms perfectly normally, something causes its faulty development in their permanent teeth. Since people with APS-1 suffer from a variety of autoimmune diseases, Abramson and his team hypothesised that the observed enamel defects may also be of an autoimmune nature

In autoimmune disease, to prevent T cells from triggering the immune system to attack body tissues, T cells developing in the thymus gland must be educated’ to discriminate between the body’s own proteins and those of foreign origin. To this end, T cells are presented with short segments of self-proteins that make up various tissues and organs in the body. When a ‘poorly educated’ T cell erroneously identifies a self-protein in the thymus as a target for attack, that T cell is labelled as dangerous and destroyed, so that it could not cause any damage after being released from the thymus.

This critical education step is impaired in APS-1 patients as a result of a mutation in a gene known as the autoimmune regulator (Aire). This gene is essential for the T cell education process: It produces a protein that is responsible for the collection of self-proteins presented to the T cells in the thymus. In their new study, scientists from Abramson’s lab in Weizmann’s Immunology and Regenerative Biology Department, led by research student Yael Gruper, sought to work out how mutations in the Aire gene lead to deficient tooth enamel production. The researchers discovered that, in the absence of Aire, proteins that play a key role in the development of enamel are not presented to the T cells in the thymus gland. As a result, T cells that are liable to identify these proteins as targets are released from the thymus, and they encourage the production of antibodies to the enamel proteins. But why do these autoantibodies damage permanent teeth and not baby teeth?

The answer to this question lies in the fact that milk teeth develop in the embryonic stage, when the immune system is not yet fully formed and cannot create autoantibodies. In contrast, the development of enamel on permanent teeth starts at birth and continues until around the age of six, when the immune system is sufficiently mature to thwart enamel development. Furthermore, the researchers found a correlation between high levels of antibodies to enamel proteins and the severity of the harm to enamel development in children with APS-1. This strengthens the assumption that the presence of enamel-specific autoantibodies in childhood can potentially lead to dental problems.

When the researchers looked into deficiencies in enamel development in people with other autoimmune diseases, they found a very similar phenomenon in children with celiac disease, a relatively common autoimmune disorder that affects around 1% of people in the West. When people with this disease are exposed to gluten, their immune system attacks and destroys the cellular layer lining the small intestine, leading to attacks on other self-proteins in the intestine.

In an attempt to understand how celiac disease, known to cause intestinal damage, may also cause damage to tooth enamel, the researchers first examined whether people with this disease have autoantibodies against enamel. They found that a large proportion of celiac patients have these autoantibodies, just as do people with APS-1. But the ‘education’ in the thymus gland of these patients seems normal, so why do they develop these antibodies? The researchers hypothesised that some proteins are found in both the intestine and the dental tissue and that these proteins play an important role in the development of tooth enamel. In this case, the antibodies that identify proteins in the intestine might move through the bloodstream to the dental tissue, where they could start to disrupt the enamel production process.

Since many celiac patients had previously been found to develop sensitivity to cow’s milk, the researchers decided to focus on the k-casein protein, a major component of dairy products. Strikingly, they found that the human equivalent of k-casein is one of the main components of the scaffold necessary for enamel formation. This led them to hypothesise that antibodies produced in the intestines of celiac patients in response to certain food antigens, such k-casein, may subsequently cause collateral damage to the development of enamel in the teeth, similarly to the way in which antibodies against gluten can eventually trigger autoimmunity against the intestine.

Indeed, they discovered that most of the children diagnosed with celiac had high levels of antibodies against k-casein from cows’ milk, which in many cases can also react against k-casein’s human equivalent expressed in the enamel matrix. This means that in theory, the same antibodies that are produced in the intestine against the milk protein could act against the human k-casein in the teeth.

These findings could have implications for the food industry. “Similarly to the lessons learned from gluten, we can assume that the consumption of large quantities of dairy products could lead to the production of antibodies against k-casein,” Abramson explains. “This protein increases the amount of cheese that can be produced from milk, so the dairy industry deliberately raises its concentration in cow’s milk. Our study, however, found that the milk k-casein is a potent immunogen, which may potentially trigger an immune response that can harm the body itself.”

Tooth enamel flaws are common, not just among people with celiac disease or APS-1. “Many people suffer from impaired tooth enamel development for unknown reasons,” Abramson says. “It is possible that the new disorder we discovered, along with the possibility of diagnosing it in a blood or saliva test, will give their condition a name. Most important, early diagnosis in children may enable preventive treatment in the future.”

Source: Weizmann Institute of Science

Tissue Regeneration might One Day Replace Root Canals

Photo by Caroline Lm on Unsplash

Tissue regeneration might one day replace the pain and discomfort of a root canal for most people. ADA Forsyth scientists are testing a novel technology to treat endodontic diseases (diseases of the soft tissue or pulp of the teeth) more effectively. The technology may also even be applicable to other parts of the body, such as helping to regrow bones.

The study, published in The Journal of Dental Research, demonstrates regenerative properties of resolvins, specifically Resolvin E1 (RvE1), when applied to dental pulp. Resolvins are part of a greater class of Specialised Proresolving Mediators (SPMs). This class of molecule is naturally produced by the body and is exquisitely effective in the control of excess inflammation associated with disease.

“Pulpitis (inflammation of dental pulp) is a very common oral health disease that can become a serious health condition if not treated properly,” said Dr Thomas Van Dyke, Vice President at the Center for Clinical and Translational Research at ADA Forsyth, and a senior scientist leading the study.

“Root canal therapy (RCT) is effective, but it does have some problems since you are removing significant portions of dentin, and the tooth dries out leading to a greater risk of fracture down the road. Our goal is to come up with a method for regenerating the pulp, instead of filling the root canal with inert material.”

Inflammation of this tissue is usually caused by damage to the tooth through injury, cavities or cracking, and the resulting infection can quickly kill the pulp and cause secondary problems if not treated.

The study applied RvE1 to different levels of infected and damaged pulp to explore its regenerative and anti-inflammatory capacities.

There were two major findings. First, they showed RvE1 is very effective at promoting pulp regeneration when used in direct pulp-capping of vital or living pulp (replicating conditions of reversible pulpitis). They were also able to identify the specific mechanism supporting tissue regeneration.

Second, the scientists found that placing RvE1 on exposed and severely infected and necrotic pulp did not facilitate regeneration.

However, this treatment did effectively slow down the rate of infection and treat the inflammation, preventing the periapical lesions (abscesses) that typically occur with this type of infection.

Previous publications have shown that if the infected root canal is cleaned before RvE1 treatment, regeneration of the pulp does occur.

While this study focused on this technology in treating endodontic disease, the potential therapeutic impact is far reaching.

Dr Van Dyke explained, “because application of RvE1 to dental pulp promotes formation of the type of stem cells that can differentiate into dentin (tooth), bone, cartilage or fat, this technology has huge potential for the field of regenerative medicine beyond the tissues in the teeth. It could be used to grow bones in other parts of the body, for instance.”

Source: Forsyth Institute

Rotary Club Elevates Paediatric Dentistry in South Africa

Dr Nicoline Potgieter at the Paediatric and Special Needs Dental Care Unit

The landscape of paediatric dental care in South Africa is poised for a significant transformation, marked by the launch of the nation’s first specialised Paediatric and Special Needs Dental Care Unit. This pioneering initiative, a result of the dedicated efforts of the Department of Paediatric Dentistry of the University of the Western Cape (UWC), The Provincial Government of the Western Cape (PGWC) and Rotary Club, is set to revolutionise Paediatric Dentistry in South Africa. It promises enhanced efficiency, a reduction in anxiety for young patients and a sharpened focus on providing dedicated oral health services to children and especially children with special health care needs.

Working towards the acknowledgment of Paediatric Dentistry as a specialty in South Africa, the need for a dedicated, specialised, child-friendly facility was identified – particularly in the Western Cape. This project stands as a steadfast response to establish such a paediatric dental unit, promising to positively impact service delivery to the children of the Western Cape.

Dalene Swart, President of the Rotary Club of Bellville, is passionate about this transformative initiative. She underscores the present scenario wherein young patients often undergo dental procedures under general anaesthesia.

“The establishment of a dedicated paediatric dentistry surgery unit, equipped with the latest materials and state-of-the-art equipment, not only enhances service quality but also serves as an invaluable training ground for postgraduate students,” she says.

However, the impact transcends mere smiles; it represents a pivotal advancement in South African healthcare, focused on the oral health of children. This project is expected to increase treatment capacity in the field of Paediatric Dentistry, thereby alleviating the workload of local healthcare professionals. It will also foster disease prevention and treatment programmes, bolster healthcare systems, and in time, significantly reduce the burden of disease and need for care under general anaesthesia.

Dr Nicoline Potgieter, president of the South African Association of Paediatric Dentistry and course coordinator for the Masters programme in Paediatric Dentistry at UWC, emphasises the enduring plight of the children in South Africa, who are in dire need of expert oral health care. “It is important to note, oral health directly impacts general health which directly impacts quality of life. It is our responsibility to provide the basic health care needs of our children. The technological advances incorporated into the unit, support minimally invasive techniques and preventative dentistry and the environment is focused on making the dental visit more pleasant for the child patient. Hopefully this is the first of many dedicated paediatric and special needs units across South Africa!”

This project, scheduled for full implementation by the end of October 2023, is the outcome of a collaboration between dedicated Rotary Club participants and the Tygerberg Oral Health Centre, which is a joint platform between UWC and PGWC. It seamlessly aligns with the UWC mission to train paediatric dentists as specialists in South Africa, reaffirming the institution’s commitment to community health and well-being. Similarly, it aligns with PGWC that is dedicated to high quality service rendering to all patients. Under this initiative, the first paediatric dentists will receive specialised training each year, while hundreds of children will benefit from disease prevention and interventions.

The project, funded with a capital expenditure of R1.2 million, draws support from various sources, including cash contributions from the Rotary Club of Bellville, Rotary Foundation and six other Rotary Clubs from the UK, USA and Canada. A significant portion of the funds raised was allocated to state-of-the-art essential dental equipment, consumables, and building materials.

Swart concludes by underlining that this project transcends immediate community needs for specialised paediatric dental care; it is about advancing medical care in South Africa and laying the groundwork for the long-term sustainability and transformation of dental care needs. This is why it enjoys unwavering support from local Rotarians.

Soft Gingival Tissues More Likely to Give Rise to Inflammation

Dentist checking teeth
Image by Caroline LM on Unsplash

The gingiva, the tissue area surrounding teeth, lets healthy teeth nestle firmly into the gums thanks to the many gingival fibres that connect the tooth to the gingiva. The gingiva is home to fibroblasts, cells that contribute to the formation of connective tissue. Scientists report in the journal Scientific Reports that they have discovered that gingival stiffness influences the properties of gingival fibroblasts, which in turn affects whether inflammation is likely to occur and make gingival fibres difficult to form.

“We discovered that soft gingiva results in inflammation and hinders the development of gingival fibres,” says Associate Professor Masahiro Yamada from Tohoku University’s Graduate School of Dentistry.

It has long been known that individuals with thick or stiff gingiva are less susceptible to gingival recessions. This is where the gingiva begins to recede and expose a tooth’s root. Many factors can lead to gingival recession, such as gum disease, over-brushing, and chewing tobacco. But this is the first time that gingival stiffness has been attributed to biological reactions.

Although fibroblasts play an important role in the maintenance, repair and healing of the gingiva, they also produce various inflammatory and tissue-degrading biomolecules which degrade the gingival fibers. In addition, fibroblasts are associated with immune responses to pathogens.

Yamada, along with his colleague Professor Hiroshi Egusa, also from the Tohoku University’s Graduate School of Dentistry, created an artificial culture environment that simulated soft or hard gingiva and cultured human gingival fibroblasts on them. They discovered that hard gingiva-simulated stiffness activated an intracellular anti-inflammatory system in the gingival fibroblasts that prevented inflammation. Yet, soft gingiva-simulated stiffness suppressed the fibroblastic anti-inflammatory system. This increased the likelihood of inflammation and resulted in less collagen synthesis.

“Our research is the first to demonstrate the biological mechanisms at play in regard to a patient’s gingival properties,” adds Yamada. “The results are expected to accelerate the development of advanced biomaterials to control local inflammation or microdevices that simulate the microenvironment of inflammatory conditions.”

Source: Tohoku University

Bacteria in Severe Oral Infections Linked to Other Diseases

Dentist checking teeth
Image by Caroline LM on Unsplash

To date, there has been little research into identifying the bacteria found in severe oral infections, despite long-suspected links to other diseases. Now, a study from Karolinska Institutet has characterised the microbial composition of these, with many known to be linked to other disease. The study is published in Microbiology Spectrum.

There is growing evidence linking oral health and common diseases, such as cancer, cardiovascular disease, diabetes and Alzheimer’s disease. However, there have been few longitudinal studies identifying which bacteria occur in infected oral- and maxillofacial regions.

Researchers at Karolinska Institutet have now analysed samples collected between 2010 and 2020 at the Karolinska University Hospital in Sweden from patients with severe oral infections and produced a list of the most common bacteria.

“We’re reporting here, for the first time, the microbial composition of bacterial infections from samples collected over a ten-year period in Stockholm County,” says Professor Margaret Sällberg Chen of the Department of Dental Medicine. “The results show that several bacterial infections with link to systemic diseases are constantly present and some have even increased over the past decade in Stockholm.”

A role in other diseases

The study shows that the most common bacterial phyla amongst the samples were Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria, while the most common genera were Streptococcus spp, Prevotella spp, and Staphylococcus spp.

“Our results provide new insight into the diversity and prevalence of harmful microbes in oral infections,” says Professor Sällberg Chen. “The finding isn’t only of importance to dental medicine, it also helps us understand the role of dental infection in patients with underlying diseases. If a certain bacterium infects and causes damage in the mouth, it’s very likely that it can be harmful to tissues elsewhere in the body as the infection spreads.”

The research group has previously shown that the occurrence of oral bacteria in the pancreas reflects the severity of pancreatic tumours.

Improve diagnostics and therapy

The study was conducted using 1014 samples from as many patients, of whom 469 were women and 545 men, and a mass-spectrometric method called MALDI-TOF that rapidly identifies individual living bacteria in a sample, but that is rarely used in dental care.

“Our study was a single centre epidemiology study and to ensure the validity of the results we need to make more and larger studies,” says adjunct Professor Volkan Özenci at the Department of Laboratory Medicine. “We now hope that dentists will collaborate with clinical microbiology laboratories more to gain a better understanding of the bacteria that cause dental infections, to improve diagnostics and therapeutic management of oral infections.”

The study is part of Khaled Al-Manei’s doctoral thesis, the next step of which is a similar epidemiological study of fungal infections in the mouth that aims to identify new fungi and microbes and understand what causes their possible malignancy. 

Source: Karolinska Institutet

Vaping Device Use Tied to Increased Risk of Developing Cavities

Photo by Chiara summer on Unsplash

Research published in The Journal of the American Dental Association found patients who said they used vaping devices were more likely to have a higher risk of developing cavities. The findings of this study on the association between vaping and risk of caries serve as an alert that this once seemingly harmless habit may be very detrimental, says Karina Irusa, assistant professor of comprehensive care at Tuftst University and lead author on the paper.

Over the last few years, public awareness has increased about the dangers of vaping to systemic health, particularly after the use of vaping devices was tied to lung disease. Some dental research has shown ties between e-cigarette use and increased markers for gum disease, and, separately, damage to the tooth’s enamel, its outer shell. But relatively little emphasis has been placed on the intersection between e-cigarette use and oral health, even by dentists, says Irusa.

Irusa says that the finding may be just a hint of the damage vaping causes to the mouth. “The extent of the effects on dental health, specifically on dental decay, are still relatively unknown,” she says. “At this point, I’m just trying to raise awareness,” among both dentists and patients.

This study, Irusa says, is the first known specifically to investigate the association of vaping and e-cigarettes with the increased risk for getting cavities. She and her colleagues analysed data from more than 13 000 patients older than 16 who were treated at Tufts dental clinics from 2019–2022.

Irusa found a significant difference in dental caries risk levels between the e-cigarette/vaping group and the control group. Some 79% of the vaping patients were categorised as having high-caries risk, compared to just about 60% of the control group. The vaping patients were not asked whether they used devices that contained nicotine or THC, although nicotine is more common.

“It’s important to understand this is preliminary data,” Irusa says. “This is not 100% conclusive, but people do need to be aware of what we’re seeing.” Further studies need to be done, and Irusa wants to take a closer look at how vaping affects the microbiology of saliva.

One reason why e-cigarette use could contribute to a high risk of cavities is the sugary content and viscosity of vaping liquid, which, when aerosolised and then inhaled through the mouth, sticks to the teeth. (A 2018 study published in the journal PLOS One likened the properties of sweet-flavoured e-cigarettes to gummy candies and acidic drinks.) Vaping aerosols have been shown to change the oral microbiome making it more hospitable to decay-causing bacteria. It’s also been observed that vaping seems to encourage decay in areas where it usually doesn’t occur – such as the bottom edges of front teeth. “It takes an aesthetic toll,” Irusa says.

The Tufts researchers recommend that dentists should routinely ask about e-cigarette use as part of a patient’s medical history, including paediatric dentists who see adolescents. According to the FDA/CDC, 7.6% of middle- and high-school students said they used e-cigarettes in 2021.

The researchers also suggest patients who use e-cigarettes should be considered for a “more rigorous caries management protocol,” which could include prescription-strength fluoride toothpaste and fluoride rinse, in-office fluoride applications, and checkups more often than twice a year.

“It takes a lot of investment of time and money to manage dental caries, depending on how bad it gets,” Irusa says. “Once you’ve started the habit, even if you get fillings, as long as you continue, you’re still at risk of secondary caries. It’s a vicious cycle that will not stop.”

Source: Tufts University