Reducing COVID-19 risk during dentist appointments

 

IMAGE: RESEARCHERS SIMULATED DENTAL TREATMENTS IN A REAL SURGERY USING A HARMLESS VIRUS TO TRACK THE SPREAD OF AEROSOLS IN THE AIR AND ON SURFACES view more 

CREDIT: UNIVERSITY OF LEEDS

Dentists could significantly increase the number of patients they see during the pandemic by switching the drills they use, according to new research. 

The study investigated whether different drill types increased or reduced the spread of aerosol spray in a dental surgery. Reducing aerosol spray results in a safer environment for patients and the dental team. 

The findings show that the time taken to prepare safe surgeries between appointments could be radically reduced by changing drills, potentially resulting in millions more treatments being carried out. 

The study, led by the University of Leeds, compared the aerosol patterns produced by dental drills rotated by air streams - that are most commonly used by UK dentists - to those produced by electric powered drills. 

Instead of simply mapping the spread of water spray during treatment, the research team instead introduced a virus that is similar in size and structure to the SARS-CoV-2 virus that causes COVID-19. 

Their results show that by replacing the high-speed air drills with lower speed electric drills, aerosol spray was virtually eliminated, creating a safer environment for both patients and the dental team. 

The research, funded by the British Endodontic Society, is published in the Journal of Dental Research. 

Lead clinical author Professor Brian Nattress, from Leeds’ School of Dentistry, said: “The issue for dentists during the coronavirus pandemic is that their routine work involves creating an aerosol spray in a confined space with an associated risk of airborne spread of COVID-19. 

“This is the first time the spread of a harmless COVID-19-like virus has been analysed during routine drilling procedures. 

“If the spread of that aerosol spray can be reduced or eradicated, that has enormous, positive implications for how dentists can go about their daily business not just during the coronavirus pandemic, but also during future virus outbreaks.” 

During the first national lockdown in England between March and June 2020, all dental surgeries were closed. 

Since reopening, because patients may be asymptomatic carriers of the SARS-CoV-2 virus when attending a dentist appointment, strict regulations have been introduced to ensure work areas are safe and prepared appropriately between appointments. Additional protective measures have been required for the dental team delivering patient care. This has led to much longer gaps between treating patients.  

Before the pandemic, about 18 million adults and children attended an NHS dental appointment each year in England. 

Reports by charity HealthWatch point to a growing backlog of patients waiting to see a dentist, with fears this could rise as the SARS-CoV-2 virus is expected to remain prevalent in the general population for many months more. 

Adjustments to the pandemic measures require high quality evidence to show how dentists can reduce the risk of spreading the SARS-CoV-2 virus when carrying out aerosol generating procedures (AGPs) during dental treatments. 

During the new research tests, use of the electric drill rather than an air drill led to a 99.98% reduction in aerosol spread of the virus into the air. 

When a dental suction tool was added, there was no detectable virus on surfaces or in air samples taken six to 10 minutes afterwards. 

The new research was carried out by the School of Dentistry, School of Civil Engineering and the Leeds Dental Institute. 

The research team set up simulated dental treatments in a real surgery scenario and - for the first time ever - used a harmless virus to track the spread of aerosols in the air and on surfaces. 

A dummy head and simulated saliva were used to measure the difference between the level of aerosols generated using a conventional air-driven dentist’s drill and a more modern electric hand piece. 

Professor David Wood, Director of Research and Innovation in the School of Dentistry, is co-author of the report. 

He said: “This robust scientific evidence addresses how the risks associated with the spread of the SARS-CoV-2 virus via dental drills can be successfully managed. 

“The recommendation we make in the report will help more people access the dental care they need, but haven’t been able to get since early 2020.” 

In light of the many restraints placed on dentists globally since the beginning of the pandemic, the research team is calling for further and essential studies to find different strategies to control the spread of dental aerosols and help to reduce the backlog of patients. 

Further information 

“Dental mitigation strategies to reduce aerosolization 1 of SARS-CoV-2”, is published in the Journal of Dental Research. 

DOI: https://doi.org/10.1177/00220345211032885 

Images and video copyright University of Leeds 

Image caption: Researchers simulated dental treatments in a real surgery using a harmless virus to track the spread of aerosols in the air and on surfaces 

Video caption: Difference in aerosol spray of a conventional air-driven dental handpiece (left) vs an electric handpiece (right) 

For further details, contact the University of Leeds press office via pressoffice@leeds.ac.uk. 

Ends 

 
 

 

---

JOURNAL

Journal of Dental Research

DOI

10.1177/00220345211032885 

Social isolation among older adults linked to having fewer teeth

Older adults who are socially isolated are more likely to have missing teeth—and to lose their teeth more quickly over time—than those with more social interaction, according to a new study of Chinese older adults led by researchers at NYU Rory Meyers College of Nursing. The findings are published in Community Dentistry and Oral Epidemiology. 

 

“Our study suggests that maintaining and improving social connections may benefit the oral health of older adults,” said Xiang Qi, a PhD student at NYU Meyers and the study’s first author. “The findings align with previous studies demonstrating that structural indicators of social disconnection can have powerful effects on indicators of health and well-being.”

 

Social isolation and loneliness in older adults are major public health concerns around the world and are risk factors for heart disease, mental health disorders, cognitive decline, and premature death. In some countries, including the United States and China, up to one in three older adults are lonely, according to the World Health Organization. The COVID-19 pandemic has exacerbated these issues among older adults, as many in-person interactions have been interrupted to protect older adults from infection.

 

Social isolation and loneliness are related but different. Social isolation is an objective measure defined as having few social relationships or infrequent social contact with others, while loneliness is the feeling created by a lack of social connection. 

 

“While social isolation and loneliness often go hand in hand, it’s possible to live alone and be socially isolated but to not feel lonely, or to be surrounded by people but still feel lonely,” said Bei Wu, Dean's Professor in Global Health at NYU Meyers and the study’s senior author.

 

Older adults are also at risk for another health concern: losing teeth. In China, older adults aged 65 to 74 have fewer than 23 teeth on average (adults typically have 32 teeth, or 28 if wisdom teeth have been removed) and 4.5% of this age group has lost all of their teeth. Gum disease, smoking, lack of access to dental care, and chronic illnesses like diabetes and heart disease increase the risks of tooth loss. Missing teeth can have a significant impact on one’s quality of life, affecting nutrition, speech, and self-esteem. 

 

To understand the relationship between social isolation, loneliness, and tooth loss in older adults in China, the researchers used the Chinese Longitudinal Healthy Longevity Survey to analyze data from 4,268 adults aged 65 and up. The participants completed surveys at three different timepoints (2011-12, 2014, and 2018), which captured measures of social isolation and loneliness, how many teeth people had and lost over the 7-year study, and other factors. More than a quarter (27.5%) of the study participants were socially isolated, and 26.5% reported feeling lonely.

 

The researchers found that higher levels of social isolation were associated with having fewer teeth and losing teeth more quickly over time, even when controlling for other factors such as oral hygiene, health status, smoking and drinking, and loneliness. Older adults who were socially isolated had, on average, 2.1 fewer natural teeth and 1.4 times the rate of losing their teeth than those with stronger social ties.

 

“Socially isolated older adults tend to be less engaged in social and health-promoting behaviors like physical activity, which could have a negative impact on their overall functioning and oral hygiene, as well as increase their risk for systemic inflammation,” said Wu. “This functional impairment seems to be a major pathway linking social isolation to tooth loss.”

 

Surprisingly, loneliness was not associated with the number of remaining teeth, nor with the rate of tooth loss.

 

“While social isolation can result in a lack of support that can affect health behaviors, for older adults who feel lonely, it’s possible that their social networks are still in place and can help them to keep up healthy behaviors,” said Qi.

 

The findings—which are relevant to countries beyond China, given that social isolation and tooth loss are global issues—highlight the importance of developing interventions to reduce social isolation. Programs could aim to foster intergenerational support within families and improve older adults' peer and social connections within their local communities. 

Feeding mode of newborns could influence oral bacteria makeup

After birth, the human mouth quickly becomes a hotbed of microbial variation. Streptococcus species largely dominate the oral cavity for the first 6 weeks of life, but the bacterial population diversifies with age and experience. Researchers study this early development, in part, to understand connections between the oral microbiota and associated diseases.

An infant’s mother is likely a major source—if not the most important one—of the early oral microbiota. This week in mBio, dental researchers in Japan report a new analysis of how new mothers share microbes with newborns. The researchers collected 892 tongue samples from 448 pairs of moms and babies (217 males, 231 females), collected when the children were 4 months old, to measure bacterial abundance and, more specifically, the abundance of single, unique DNA sequences, called amplicon sequence variants (ASV), shared between mother and child.
 
Shared ASVs in newborns ranged from almost none to almost 100%, said Yoshihisa Yamashita, Ph.D, at Kyushu University in Japan, senior author of the study. “The acquisition level of maternal oral bacteria varied widely among individuals,” he said. The median relative abundance of ASV that newborns shared with their mothers, however, was 9.7%, which the researchers noted was significantly higher than the abundance of ASVs newborns shared with other, unrelated mothers. The study was led by Shinya Kageyama, Ph.D, also at Kyushu University. 
 
Notably, the shared abundance and composition varied significantly by how the infant fed. Infants who breastfed exclusively shared fewer ASVs with their mothers than infants fed exclusively with formula or fed with some combination of breastfeeding and formula. Breastfed infants also had a bacterial composition most unrelated to the mother’s compared to other groups. The researchers found no difference in abundance linked to the age, sex, delivery mode, family smoking status or antibiotic use of the infants.

The researchers offered 2 hypotheses to explain the difference. “One is that protective factors of breast milk regulate mother-derived oral bacterial colonization,” said Yamashita. The second is that the different substrates provided by formula and breast milk influence the balance of bacteria in the mouth.

Unlike previous studies that have reported shared microbes between mothers and infants, the new work includes a full-length analysis of all 9 hypervariable regions in the 16s rRNA gene. In addition, the authors noted that the ASV approach allows for the identification of DNA sequences that differ by as little as a single nucleotide.

At Kyushu University, the researchers focus on connecting early-life oral microbiota to the risk of disease later in life. Previous studies have linked certain bacteria to cavities in the teeth and periodontitis. More recent research, however, has also reported that microbes usually found in the mouth show up in the gut in people with serious conditions ranging from liver cirrhosis to inflammatory bowel disease to colorectal cancer.

The new findings, said Yamashita, are “vital as a foundation for further studies.” The group plans to follow the same study population, with the next examination of the oral microbiota and clinical conditions set for the infants’ 3-year checkups. 

Bacteria that cause periodontal disease reduce oral defense and increase viral growth

Researchers from the University of Louisville School of Dentistry and their colleagues have discovered details of how proteins produced by oral epithelial cells protect humans against viruses entering the body through the mouth. They also found that oral bacteria can suppress the activity of these cells, increasing vulnerability to infection.

A family of proteins known as interferon lambdas produced by epithelial cells in the mouth serve to protect humans from viral infection, but the oral bacteria Porphyromonas gingivalis reduces the production and effectiveness of those important frontline defenders.

“Our studies identified certain pathogenic bacterial species, P. gingivalis, which cause periodontal disease, can completely suppress interferon production and severely enhance susceptibility to viral infection,” said Juhi Bagaitkar, assistant professor in the UofL Department of Oral Immunology and Infectious Disease. “These resident oral plaque bacteria play a key role in regulating anti-viral responses.”

Bagaitkar and Richard Lamont, professor and chair of the UofL Department of Oral Immunology and Infectious Disease, led the work, with first author Carlos J. Rodriguez-Hernandez and other colleagues at UofL and at Washington University in St. Louis. The findings were published in December in PNAS.

The mouth often is a gateway into the body for viruses that infect the gastrointestinal tract and lungs such as SARS-CoV-2, human immunodeficiency virus (HIV), herpes simplex and cancer-causing viruses such as human papillomavirus (HPV).

P. gingivalis, a common oral bacterium that causes periodontal disease, has been linked to numerous other diseases, including Alzheimer’s disease and rheumatoid arthritis. Recent clinical studies have shown that immune suppression in patients with periodontitis can enhance susceptibility to HIV, herpes simplex and HPV.

Improved understanding of how interferons provide broad antiviral protection and activate antiviral genes to protect people from viruses, as well as how P. gingivalis compromises their protection, may lead researchers to clinical approaches to increase that protection.

Research at UofL has revealed connections between P. gingivalis and multiple other diseases and conditions, including rheumatoid arthritis, Alzheimer’s disease and esophageal cancer.

Report details 20 years of advances and challenges of Americans’ oral health

NIH’s new report, Oral Health in America: Advances and Challenges, provides a road map on how to improve the nation’s oral health. NIDCR

Despite important advances in the understanding and treatment of oral diseases and conditions, many people in the U.S. still have chronic oral health problems and lack of access to care, according to a report by the National Institutes of Health. Oral Health in America: Advances and Challenges, is a follow-up to the seminal 2000 Oral Health in America: A Report of the Surgeon General. The new report, which is intended to provide a road map on how to improve the nation’s oral health, draws primarily on information from public research and evidence-based practices and was compiled and reviewed by NIH’s National Institute of Dental and Craniofacial Research (NIDCR) and a large, diverse, multi-disciplinary team of more than 400 experts.

The report updates the findings of the 2000 publication and highlights the national importance of oral health and its relationship to overall health. It also focuses on new scientific and technological knowledge – as well as innovations in health care delivery – that offer promising new directions for improving oral health care and creating greater equity in oral health across communities. Achieving that equity is an ongoing challenge for many who struggle to obtain dental insurance and access to affordable care.

“This is a very significant report,” said NIH Acting Director Lawrence A. Tabak, D.D.S., Ph.D. “It is the most comprehensive assessment of oral health currently available in the United States and it shows, unequivocally, that oral health plays a central role in overall health. Yet millions of Americans still do not have access to routine and preventative oral care.”

The newly issued report provides a comprehensive snapshot of oral health in America, including an examination of oral health across the lifespan and a look at the impact the issue has on communities and the economy. Major take-aways from the report include:

• Healthy behaviors can improve and maintain an individual’s oral health, but these behaviors are also shaped by social and economic conditions.
• Oral and medical conditions often share common risk factors, and just as medical conditions and their treatments can influence oral health, so can oral conditions and their treatments affect other health issues.
• Substance misuse and mental health conditions negatively affect the oral health of many.
• Group disparities around oral health, identified 20 years ago, have not been adequately addressed, and greater efforts are needed to tackle both the social and commercial determinants that create these inequities and the systemic biases that perpetuate them.

“This is an in-depth review of the scientific knowledge surrounding oral health that has accumulated over the last two decades,” said Rena D’Souza D.D.S., Ph.D., director of NIDCR, which oversaw and funded the project’s three-year research program. “It provides an important window into how many societal factors intersect to create advantages and disadvantages with respect to oral health, and, critically, overall health.”

The COVID-19 pandemic emerged while the report was being written. The science around SARS-CoV-2 continues to come into focus in real-time, and, although data were only starting to surface about the oral implications of the disease, the authors included a preliminary analysis of it to assess initial impacts.

The authors make several recommendations to improve oral health in America, which include the need for health care professionals to work together to provide integrated oral, medical, and behavioral health care in schools, community health centers, nursing homes, and medical care settings, as well as dental clinics. They also identify the need to improve access to care by developing a more diverse oral health care workforce, addressing the rising cost of dental education, expanding insurance coverage, and improving the overall affordability of care.

“Although there are challenges ahead, the report gives us a starting point and some clear goals that offer reasons to be hopeful, despite those challenges,” added D’Souza. “It imagines a future, as I do, in which systemic inequities that affect oral health and access to care are more fully addressed, and one in which dental and medical professionals work together to provide integrated care for all.”

Scientists and public health professionals will use the report to identify areas of scientific inquiry and research as well as develop and implement programs that ultimately will improve the oral health of individuals, communities, and the nation.

To view or download the report, please visit the NIDCR website at https://www.nidcr.nih.gov/oralhealthinamerica.

Questions about the report? Email OralHealthReport@nih.gov(link sends e-mail) or call NIDCR at 1-866-232-4528.

About the National Institute of Dental and Craniofacial Research: NIDCR is the nation’s leading funder of research on oral, dental, and craniofacial health.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

Gum disease increases risk of other illness such as mental health and heart conditions

A University of Birmingham-led study shows an increased risk of patients developing illnesses including mental ill-health and heart conditions if they have a GP-inputted medical history of periodontal (gum) disease

Experts carried out a first of its kind study of the GP records of 64,379 patients who had a GP-inputted recorded history of periodontal disease, including gingivitis and periodontitis (the condition that occurs if gum disease is left untreated and can lead to tooth loss).  Of these, 60,995 had gingivitis and 3,384 had periodontitis. These patients’ records were compared to those of 251,161 patients who had no record of periodontal disease. Across the cohorts, the average age was 44 years and 43% were male, while 30% were smokers. Body Mass Index (BMI), ethnicity and deprivation levels were also similar across the groups.

The researchers examined the data to establish how many of the patients with and without periodontal disease go on to develop cardiovascular disease (e.g., heart failure, stroke, vascular dementia), cardiometabolic disorders (e.g., high blood pressure, Type 2 diabetes), autoimmune conditions (e.g., arthritis, Type 1 diabetes, psoriasis), and mental ill-health (e.g., depression, anxiety and serious mental illness) over an average follow-up of around three years.

From the research, published today in journal BMJ Open, the team discovered that those patients with a recorded history of periodontal disease at the start of the study were more likely to go on and be diagnosed with one of these additional conditions over an average of three years, compared to those in the cohort without periodontal disease at the beginning of the research.  The results of the study showed, in patients with a recorded history of periodontal disease at the start of the study, the increased risk of developing mental ill-health was 37%, while the risk of developing autoimmune disease was increased by 33%, and the risk of developing cardiovascular disease was raised by 18%, while the risk of having a cardiometabolic disorder was increased by 7% (with the increased risk much higher for Type 2 diabetes at 26%).

Co-first author, Dr Joht Singh Chandan, of the University of Birmingham’s Institute of Applied Health Research, said: “Poor oral health is extremely common, both here in the UK and globally.  When oral ill-health progresses, it can lead to a substantially reduced quality of life.  However, until now, not much has been known about the association of poor oral health and many chronic diseases, particularly mental ill-health.  Therefore, we conducted one of the largest epidemiological studies of its kind to date, using UK primary care data to explore the association between periodontal disease and several chronic conditions.  We found evidence that periodontal disease appears to be associated with an increased risk of developing these associated chronic diseases. As periodontal diseases are very common, an increased risk of other chronic diseases may represent a substantial public health burden.”

Co-first author, Dr Dawit Zemedikun, of the University of Birmingham’s Institute of Applied Health Research, said: “Our study was the most comprehensive study of its kind and the results provided vital confirmation of evidence which has previously either been lacking in strength or has had gaps – particularly the association between oral ill-health and mental ill-health.”

Co-senior author, Professor Krish Nirantharakumar, also of the University of Birmingham’s Institute of Applied Health Research, said:  “An important implication of our findings is the need for effective communication between dental and other healthcare professionals to ensure patients obtain an effective treatment plan targeting both oral and wider health to improve their existing overall health and reduce the risk of future illness.”

Periodontal specialist, Dr Devan Raindi, of the University of Birmingham’s School of Dentistry, said: “This study strengthens the continually evolving research associating periodontal disease, in particular periodontitis, and various general health conditions. It reinforces the importance of prevention, early identification and treatment of periodontitis and the need for members of the public to attend regular oral health checks with a dentist or dental care professional.”

The research was partly funded by Versus Arthritis’s Centre for Musculoskeletal Ageing Research based at the University of Birmingham, and supported by the National Institute for Health Research (NIHR) Birmingham Biomedical Research Centre.

Caroline Aylott, Head of Research Delivery at Versus Arthritis, said: “Some of the biggest challenges of arthritis, especially auto-immune conditions like rheumatoid arthritis (RA) which affects 400,000 people in the UK, is being able to know who is more at risk of developing it, and finding ways to prevent it. Previous studies have shown that people with RA were four times more likely to have gum disease than their RA-free counterparts and it tended to be more severe. This research provides further clear evidence why healthcare professionals need to be vigilant for early signs of gum disease and how it can have wide-reaching implications for a person’s health, reinforcing the importance of taking a holistic approach when treating people.”

“Good job brushing your teeth!”

 

Study Shows Parent Praise Might Encourage Children’s Persistence

To become healthy and successful adults, children need to persist on tasks that they might not necessarily consider easy or fun, like studying, exercising, or brushing one’s teeth. Throughout childhood, persistence behavior changes daily, but the factors that shape this variability in persistence are understudied. A new study published in Child Development by researchers at the University of Pennsylvania, Yale University and the Sante Fe Institute, analyzed daily toothbrushing behaviors in three-year-olds and examined the relationship between their persistence on the task and parental praise.

“Our work is the first to show that fluctuations in parent praise relate to fluctuations in child persistence,” said Allyson Mackey, assistant professor of psychology at the University of Pennsylvania. “We examined how variations in parent talk and stress, and child mood and sleep, separately impacted fluctuations in brushing time. Surprisingly, parents were not able to accurately predict which variables shaped brushing in their own children.”

The study included eight-one three-year-olds learning to brush their own teeth. The sample was 80% White, 14% Multiracial, 10% Hispanic or Latinx, 2% Asian, 1% Black and 1% preferred not to answer. Data was collected from families in Pennsylvania (94%) with the remaining in New Jersey, Delaware, Massachusetts, Maryland, and Florida. Parental education averaged from 12 to 20 years and the annual income ranged from $14,000 to $200,000. Data were collected throughout a 16-day period in two waves: January-June 2019 and March-May 2020 (during the COVID-19 pandemic). Families were recruited through partnerships with local preschools and through social media.

Parents submitted videos of nightly toothbrushing over 16 days, capturing both children’s persistence and parent talk. Parents were instructed to start recording the video before the toothbrush was in their child’s mouth and to stop recording when they took the toothbrush back from their child. Parents were asked to let their child brush their teeth by themselves for as long as they could before the parent stepped in to help. (If children did not brush their teeth for a night, resulting in no video, parents were instructed to let the researchers know). The videos also included parents talking to their child throughout the toothbrushing and “praise” used by parents throughout the nightly ritual. Praise was broken into categories including “process praise” (e.g., “good job”), “person praise” (e.g., “good girl”), and “other praise” (e.g., “very good” or “nice”). Other utterances from parents included “distraction” (e.g., singing, reading a book, invoking pretend play), and using expressions such as “brush the backs” and “keep brushing” as instruction.

Parents also completed daily surveys about the following:

• Parental nightly stress level: ranging from a scale of 0 (not stressed at all) to 10 (extremely stressed)
• Child’s mood: ranging from a scale of 0 (extremely bad) to 10 (extremely good)
• Sleep duration: daytime nap (if any) and length, nightly bedtime and morning wake up, periods of awake time during the night

The findings showed that children’s persistence fluctuates from day to day and is related to parent talk. Children brushed longer on days when their parents used more praise and less instruction. Parent praise during toothbrushing mostly consisted of generic praise and process (e.g., “nice” and “great job”), with few instances of person praise (e.g., “good girl”). Children varied in their sensitivity to mood, sleep, and parent stress.

“Our work provides a path towards identifying the specific factors that impact individual children’s persistence to design targeted interventions, some of which parents may not find obvious,” said Julia Leonard, assistant professor of psychology at Yale University. “Our work also demonstrates a new approach to studying children’s healthy development - instead of focusing on what factors make one group of children different from another, our study asked which factors make individual children more like the best version of themselves.”

The authors acknowledge several limitations of the study. The exact set of skills involved in toothbrushing are not yet known, the sample was skewed toward higher-income families within a Western, Educated, Industrialized, Rich, and Democratic (WEIRD) cultural context, potential bias in parental reporting and modifications in their behavior, lack of data on the quality of children’s sleep and morning toothbrushing. In addition, this study does not tell us whether parent praise causes positive changes in children’s behavior. To determine this, intervention studies are needed. Future research should consider a larger sample, whether results will differ beyond the pandemic and whether variables such as a good night sleep make an impact in the response to children’s social input. Toothbrushing was selected as the task in this study as it is an everyday, naturalistic task that is not particularly interesting or fun for children but is important for children’s health However, future work should test whether these findings could be used to translate children’s daily fluctuations on other tasks that require persistence including those with more immediate and delayed rewards.