The oral microbiomes of 25 otherwise healthy participants who use e-cigarettes daily closely match those seen in patients with gum disease, a new study shows. The results suggest that e-cigarettes trigger a proinflammatory response, coating commensal bacteria in the mouth with a layer of slime that makes them unrecognizable to the body and prevents the sequential colonization of other bacteria that form a healthy community. Sukirth Ganesan and colleagues conclude that the glycerol/glycol vehicle in e-cigarettes appears to drive these changes.
E-cigarettes have grown wildly popular among Americans, with six percent of the country's population - including 2.5 million high schoolers - puffing on the products nine years after their introduction to the United States. But while these e-cigarettes contain potentially toxic substances, including volatile organic compounds and metals, much remains unknown their long-term effects on human health.
To gain insight into how e-cigarettes affect the oral microbiome, Ganesan et al. recruited 123 otherwise healthy individuals, including 25 smokers, 25 nonsmokers, 20 e-cigarette users, 25 former smokers currently using e-cigarettes, and 28 smokers who also use e-cigarettes. They created a catalog of bacterial genes in the microbial communities of e-cigarette users based on plaque samples collected from their teeth, finding that variations arose based on the duration of e-cigarette use, but were not tied to variations in the concentration of nicotine or the type of flavoring.
The researchers also observed that while both smoking and e-cigarette use cause inflammation, they do so through different molecular pathways.
"I am hoping this research will drive some level of policymaking about the harm we are seeing," said Purnima Kumar, a coauthor of the study, in an interview, challenging the popular perception that e-cigarettes provide a safer alternative to smoking. "If we can see changes in people who are otherwise healthy and have nothing wrong with them, then we should start seriously considering why would you put their lives and their wellbeing at risk."
Though non-opioid painkillers can be just as effective, patients having dental procedures just before weekends and holidays are more likely to fill prescriptions for opioids
IMAGE: KEY FINDINGS FROM A STUDY OF MORE THAN 2 MILLION AMERICANS WHO HAD DENTAL PROCEDURES IN THE PRE-COVID19 ERA view more
CREDIT: UNIVERSITY OF MICHIGAN/JADA
As dentists and their teams across America get back to their regular schedules after a sharp COVID-19-related reduction, a new study shows a key opportunity to reduce the use of opioid painkillers by their patients.
The analysis of four years' worth of datafrom two million patients show that those who had dental procedures on a Friday or a day before a holiday were much more likely to fill a prescription for an opioid than other patients.
Teens and young adults were the most likely to get opioids, which were likely prescribed in order to get them through the weekend or holiday break without needing to contact the dentist for pain care.
One in five of the patients, all between the ages of 13 and 64, filled a prescription for an opioid, even though non-opioid pain medications are equally effective at controlling pain and have lower risks.
Those who had pre-weekend or pre-holiday procedures were 27% more likely to pick up an opioid prescription. If they were teens or young adults, they were 43% more likely than older patients to do so.
The new findings, reported in the Journal of the American Dental Association by a team from the University of Michigan, build on prior work showing overprescribing of opioids by dentists with no increase in pain relief or patient satisfaction .
The rate of weekend and holiday opioid prescription-filling by young people is especially troubling because of previous work showing that those who get opioids after getting their wisdom teeth out are nearly three times as likely to keep refilling the prescription long after their mouths should have healed.
"Variation in opioid prescription fills may put some patients at increased risk," says Caitlin Priest, the U-M Medical School student who led the analysis as part of the Michigan Opioid Prescribing Engagement Network team. "Now that we understand that dental opioid prescription fills were increased on Fridays and before holidays, we can create and disseminate best practices to avoid unnecessary prescribing."
Just over half of the patients whose records were analyzed had their dental procedure on an emergency basis. But the rest were scheduled - one-fifth of them on Fridays and the days before holidays.
Half of the patients who filled an opioid prescription had had scheduled surgical tooth extractions, but the pre-weekend and pre-holiday increase was seen across all 11 dental procedures studied.
This suggests multiple opportunities to reduce unneeded opioid prescribing, says Romesh Nalliah, M.H.C.M., D.D.S., the associate dean for patient services at the U-M School of Dentistry and a member of the study team. He notes that patients may seek Friday and pre-holiday appointments for their scheduled procedures to avoid missing work as they recover.
"The significance of our study is that, with the help of big data, it begins to unpack potentially harmful opioid prescribing trends that were not previously understood," he says. "In the event that we have particular concerns about a given case or patient, we can more deliberately book surgeries when we are available to follow-up."
The senior author of the paper, Chad Brummett, M.D., co-directs Michigan OPEN, which has published evidence-based guidelines for opioid prescribing for acute pain caused by many types of procedures and operations. He is also director of pain research in the Department of Anesthesiology at Michigan Medicine, U-M's academic medical center.
The guidelines say that for dental extractions, non-steroidal anti-inflammatory medications and over-the-counter pain relievers should be sufficient for pain control.
Examining bacteria growing on toddlers' teeth, a team from the University of Pennsylvania and Georgia Tech found that the microbes' spatial organization is crucial to how they cause tooth decay
IMAGE: RESEARCHERS FROM THE UNIVERSITY OF PENNSYLVANIA FOUND THAT THE BACTERIA RESPONSIBLE FOR TOOTH DECAY "SHIELDS " ITSELF UNDER BLANKETS OF SUGARS AND OTHER BACTERIA IN A CROWN-LIKE ARRANGEMENT, HELPING IT EVADE... view more
CREDIT: DONGYEOP KIM
Studying bacteria in a petri dish or test tube has yielded insights into how they function and, in some cases, contribute to disease. But this approach leaves out crucial details about how bacteria act in the real world.
Taking a translational approach, researchers at the University of Pennsylvania School of Dental Medicine and the Georgia Institute of Technology imaged the bacteria that cause tooth decay in three dimensions in their natural environment, the sticky biofilm known as dental plaque formed on toddlers' teeth that were affected by cavities.
The work, published in the journal Proceedings of the National Academy of Sciences, found that Streptococcus mutans, a major bacterial species responsible for tooth decay, is encased in a protective multilayered community of other bacteria and polymers forming a unique spatial organization associated with the location of the disease onset.
"We started with these clinical samples, extracted teeth from children with severe tooth decay," says Hyun (Michel) Koo of Penn Dental Medicine, a co-senior author on the work. "The question that popped in our minds was, how these bacteria are organized and whether their specific architecture can tell us about the disease they cause?"
To address this question, the researchers, including lead author Dongyeop Kim of Penn Dental Medicine and co-senior author Marvin Whiteley of Georgia Tech, used a combination of super-resolution confocal and scanning electron microscopy with computational analysis to dissect the arrangement of S. mutans and other microbes of the intact biofilm on the teeth. These techniques allowed the team to examine the biofilm layer by layer, gaining a three-dimensional picture of the specific architectures.
This approach, of understanding the locations and patterns of bacteria, is one that Whiteley has pursued in other diseases.
"It's clear that identifying the constituents of the human microbiome is not enough to understand their impact on human health," Whiteley says. "We also have to know how they are spatially organized. This is largely under studied as obtaining intact samples that maintain spatial structure is difficult."
In the current work, the researchers discovered that S. mutans in dental plaque most often appeared in a particular fashion: arranged in a mound against the tooth's surface. But it wasn't alone. While S. mutans formed the inner core of the rotund architecture, other commensal bacteria, such as S. oralis, formed additional outer layers precisely arranged in a crownlike structure. Supporting and separating these layers was an extracellular scaffold made of sugars produced by S. mutans, effectively encasing and protecting the disease-causing bacteria.
"We found this highly ordered community with a dense accumulation of S. mutans in the middle surrounded by these 'halos' of different bacteria, and wondered how this could cause tooth decay," Koo says. "
To learn more about how structure impacted the function of the biofilm, the research team attempted to recreate the natural plaque formations on a toothlike surface in the lab using S. mutans, S. oralis, and a sugar solution. They successfully grew rotund-shaped architecture and then measured levels of acid and demineralization associated with them.
"What we discovered, and what was exciting for us, is that the rotund areas perfectly matched with the demineralized and high acid levels on the enamel surface," says Koo. "This mirrors what clinicians see when they find dental caries: punctuated areas of decalcification known as 'white spots.' The domelike structure could explain how cavities get their start."
In a final set of experiments, the team put the rotund community to the test, applying an antimicrobial treatment and observing how the bacteria fared. When the rotund structures were intact, the S. mutans in the inner core largely avoided dying from the antimicrobial treatment. Only breaking up the scaffolding material holding the outer layers together enabled the antimicrobial to penetrate and effectively kill the cavity-causing bacteria.
The study's findings may help researcher more effectively target the pathogenic core of dental biofilms but also have implications for other fields.
"It demonstrates that the spatial structure of the microbiome may mediate function and the disease outcome, which could be applicable to other medical fields dealing with polymicrobial infections," says Koo.
"It's not just which pathogens are there but how they're structured that tells you about the disease that they cause," adds Whiteley. "Bacteria are highly social creatures and have friends and enemies that dictate their behaviors."
The field of microbial biogeography is young, the researchers say, but extending this demonstration that links community structure with disease onset opens up a vast array of possibilities for future medically relevant insights.
May 11, 2020, Alexandria, Va., USA--The Journal of Dental Research published today the results of a study that demonstrated that community water fluoridation is not associated with increased risk of osteosarcoma.
More than sixty percent of the U.S. population have access to community water fluoridation, considered to be one of the most important public health policies of the twentieth century due to its reduction of tooth decay at the population level. Fluoride ingestion has been suggested as a possible risk factor for osteosarcoma based on a 1990 animal study. Six of the seven subsequent case-control studies in humans reported that fluoride in drinking water was not associated with osteosarcoma.
This study assessed whether living in a fluoridated community was a risk factor for osteosarcoma by performing a secondary data analysis using data collected from two separate, but linked studies. Patients for both Phase 1 and Phase 2 were selected from U.S. hospitals using a hospital-based matched case-control study design. For both phases, cases were patients diagnosed with osteosarcoma and controls were patients diagnosed with other bone tumors or non-neoplastic conditions.
In Phase 1, cases (N=209) and controls (N=440) were patients of record in the participating orthopedic departments from 1989-1993. In Phase 2, cases (N=108) and controls (N=296) were incident patients who were identified and treated by orthopedic physicians from 1994-2000. This analysis included all patients who met eligibility criteria on whom we had complete data on covariates, exposures, and outcome. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association of community water fluoridation with osteosarcoma.
The adjusted OR, for osteosarcoma and ever-having lived in a fluoridated area for non-bottled water drinkers was 0.51(0.31 - 0.84), p=0.008. The same comparison adjusted OR for bottled water drinkers was 1.86 (0.54 - 6.41), p=0.326.
"These results indicate that residence in a fluoridated community is not related to an increase in risk for osteosarcoma after adjusting for race, ethnicity, income, distance from the hospital, urban/rural living status, and drinking bottled water. This should not be surprising given that ingestion of fluoridated water is a common exposure and osteosarcoma remains a rare disease," said Chester Douglass; Harvard School of Dental Medicine, Department of Oral Health Policy and Epidemiology.
