Wednesday, July 21, 2021

Preventing approximal caries in primary teeth with topical fluorides


INTERNATIONAL & AMERICAN ASSOCIATIONS FOR DENTAL RESEARCH

Research News

Alexandria, Va., USA - Parach Sirivichayakul, Mahidol University, Bangkok, Thailand, presented the poster "Preventing Approximal Caries in Primary Teeth With Topical Fluorides" at the virtual 99th General Session & Exhibition of the International Association for Dental Research (IADR), held in conjunction with the 50th Annual Meeting of the American Association for Dental Research (AADR) and the 45th Annual Meeting of the Canadian Association for Dental Research (CADR), on July 21-24, 2021.

There is limited evidence regarding the use of silver diamine fluoride (SDF) for caries prevention in primary teeth. This randomized clinical trial evaluated the effectiveness of 38% SDF, 5% sodium fluoride (NaF) varnish and placebo control in preventing approximal caries in primary teeth.

Children aged 4-6 years who had at least one sound approximal surface at the distal surface of canines or the mesial or distal surface of the first and second molars assessed from bitewing radiographs were recruited. The participants were randomly allocated into three intervention groups as follows: Group 1 = control (water) , Group 2 = 5% NaF varnish (Duraphat) and Group 3 = 38% SDF (Topamine). All agents were applied semi-annually and the new caries development was assessed by the bitewing radiographic examinations at 6-, 12-, and 18-month follow-ups by two blind calibrated investigators.

The new approximal caries development rates of Group 1, 2, and 3 at the 18-month examination were 22.5%, 13.6%, and 24.3%, respectively (p<0.001). Based on these results, the semi-annual application of 5% NaF varnish is more effective than that of 38% SDF and the placebo control in preventing approximal caries in primary teeth.

View this poster presentation in the IADR General Session Virtual Experience Platform.

Wednesday, July 14, 2021

Study reveals new aspects of gingivitis and body's response


Links to other health issues suggested

UNIVERSITY OF WASHINGTON SCHOOL OF DENTISTRY

Research News

IMAGE

IMAGE: A GINGIVAL BACTERIAL SAMPLE IS TAKEN FROM A SUBJECT. view more 

CREDIT: DR. SHATHA BAMASHMOUS, UNIVERSITY OF WASHINGTON SCHOOL OF DENTISTRY

UW researchers reveal new aspects of gum disease and body's protective response

SEATTLE - A team led by University of Washington researchers has, for the first time, identified and classified how different people respond to the accumulation of dental plaque, the sticky biofilm that gathers on teeth. Their work, recently published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), sheds important new light on why some people may be more prone to serious conditions that lead to tooth loss and other problems.

Left unchecked, plaque buildup can induce gingivitis, or gum inflammation. Gingivitis, in turn, can lead to periodontitis, a serious gum infection that damages the soft tissue and can destroy the bone that supports teeth. Not only can this result in tooth loss, but chronic inflammation can also spur other serious health consequences, including heart disease, diabetes, cancer, arthritis, and bowel diseases.

The researchers also found a previously unidentified range of inflammatory responses to bacterial accumulation in the mouth. When bacteria build up on tooth surfaces, it generates inflammation, a tool the body uses to tamp down the buildup. Previously, there were two known major oral inflammation phenotypes, or individual traits: a high or strong clinical response and a low clinical response. The team identified a third phenotype, which they called "slow": a delayed strong inflammatory response in the wake of the bacterial buildup.

The study revealed for the first time that subjects with low clinical response also demonstrated a low inflammatory response for a wide variety of inflammation signals. "Indeed, this study has revealed a heterogeneity in the inflammatory response to bacterial accumulation that has not been described previously," said Dr. Richard Darveau of the UW School of Dentistry, one of the study's authors.

His School of Dentistry colleague and study co-author Dr. Jeffrey McLean said, "We found a particular group of people that have a slower development of plaque as well as a distinct microbial community makeup prior to the start of the study." The study authors wrote that understanding the variations in gum inflammation could help better identify people at elevated risk of periodontitis. In addition, it is possible that this variation in the inflammatory response among the human population may be related to susceptibility to other chronic bacterial-associated inflammatory conditions such as inflammatory bowel disease.

In addition, the researchers found a novel protective response by the body, triggered by plaque accumulation, that can save tissue and bone during inflammation. This mechanism, which was apparent among all three phenotypes, utilizes white blood cells known as neutrophils. In the mouth, they act something like cops on the beat, patrolling and regulating the bacterial population to maintain a stable condition known as healthy homeostasis.

In this instance, plaque is not a villain. To the contrary, the researchers said that the proper amount and makeup of plaque supports normal tissue function. Studies in mice have also shown that plaque also provides a pathway for neutrophils to migrate from the bloodstream through the gum tissue and into the crevice between the teeth and gums.

When healthy homeostasis exists and everything is working right, the neutrophils promote colonization resistance, a low-level protective inflammatory response that helps the mouth fend off an excess of unhealthy bacteria and resist infection. At the same time, the neutrophils help ensure the proper microbial composition for normal periodontal bone and tissue function.

The researchers' findings underscore why dentists preach the virtues of regular brushing and flossing, which prevent too much plaque buildup. "The idea of oral hygiene is to in fact recolonize the tooth surface with appropriate bacteria that participate with the host inflammatory response to keep unwanted bacteria out," Dr. Darveau said. The bacteria start repopulating the mouth's surfaces spontaneously and almost immediately afterward, he said.

Friday, July 9, 2021

Tooth loss associated with increased cognitive impairment, dementia


Good oral health, including dentures, may protect against cognitive decline

NEW YORK UNIVERSITY

Research News

Tooth loss is a risk factor for cognitive impairment and dementia--and with each tooth lost, the risk of cognitive decline grows, according to a new analysis led by researchers at NYU Rory Meyers College of Nursing and published in JAMDA: The Journal of Post-Acute and Long-Term Care Medicine. However, this risk was not significant among older adults with dentures, suggesting that timely treatment with dentures may protect against cognitive decline.

About one in six adults aged 65 or older have lost all of their teeth, according to the Centers for Disease Control and Prevention. Prior studies show a connection between tooth loss and diminished cognitive function, with researchers offering a range of possible explanations for this link. For one, missing teeth can lead to difficulty chewing, which may contribute to nutritional deficiencies or promote changes in the brain. A growing body of research also points to a connection between gum disease--a leading cause of tooth loss--and cognitive decline. In addition, tooth loss may reflect life-long socioeconomic disadvantages that are also risk factors for cognitive decline.

"Given the staggering number of people diagnosed with Alzheimer's disease and dementia each year, and the opportunity to improve oral health across the lifespan, it's important to gain a deeper understanding of the connection between poor oral health and cognitive decline," said Bei Wu, PhD, Dean's Professor in Global Health at NYU Rory Meyers College of Nursing and co-director of the NYU Aging Incubator, as well as the study's senior author.

Wu and her colleagues conducted a meta-analysis using longitudinal studies of tooth loss and cognitive impairment. The 14 studies included in their analysis involved a total of 34,074 adults and 4,689 cases of people with diminished cognitive function.

The researchers found that adults with more tooth loss had a 1.48 times higher risk of developing cognitive impairment and 1.28 times higher risk of being diagnosed with dementia, even after controlling for other factors.

However, adults missing teeth were more likely to have cognitive impairment if they did not have dentures (23.8 percent) compared to those with dentures (16.9 percent); a further analysis revealed that the association between tooth loss and cognitive impairment was not significant when participants had dentures.

The researchers also conducted an analysis using a subset of eight studies to determine if there was a "dose-response" association between tooth loss and cognitive impairment--in other words, if a greater number of missing teeth was linked to a higher risk for cognitive decline. Their findings confirmed this relationship: each additional missing tooth was associated with a 1.4 percent increased risk of cognitive impairment and 1.1 percent increased risk of being diagnosed with dementia.

"This 'dose-response' relationship between the number of missing teeth and risk of diminished cognitive function substantially strengthens the evidence linking tooth loss to cognitive impairment, and provides some evidence that tooth loss may predict cognitive decline," said Xiang Qi, a doctoral candidate from NYU Meyers.

"Our findings underscore the importance of maintaining good oral health and its role in helping to preserve cognitive function," said Wu.

Monday, June 28, 2021

Pulling wisdom teeth can improve long-term taste function


Penn Medicine study shows, for the first time, positive long-term effects of third molar extraction on taste

UNIVERSITY OF PENNSYLVANIA SCHOOL OF MEDICINE

Research News

-Patients who had their wisdom teeth extracted had improved tasting abilities decades after having the surgery, a new Penn Medicine study published in the journal Chemical Senses found. The findings challenge the notion that removal of wisdom teeth, known as third molars, only has the potential for negative effects on taste, and represent one of the first studies to analyze the long-term effects of extraction on taste.

"Prior studies have only pointed to adverse effects on taste after extraction and it has been generally believed that those effects dissipate over time," said senior author Richard L. Doty, PhD, director of the Smell and Taste Center at the University of Pennsylvania. "This new study shows us that taste function can actually slightly improve between the time patients have surgery and up to 20 years later. It's a surprising but fascinating finding that deserves further investigation to better understand why it's enhanced and what it may mean clinically."

Doty and co-author Dane Kim, a third-year student in the University of Pennsylvania School of Dental Medicine, evaluated data from 1,255 patients who had undergone a chemosensory evaluation at Penn's Smell and Taste Center over the course of 20 years. Among that group, 891 patients had received third molar extractions and 364 had not.

The "whole-mouth identification" test incorporates five different concentrations of sucrose, sodium chloride, citric acid, and caffeine. Each solution is sipped, swished in the mouth, and then spit out. Subjects then indicate whether the solution tastes sweet, salty, sour, or bitter.

The extraction group outperformed the control group for each of the four tastes, and in all cases, women outperformed men. The study suggests, for the first time, that people who have received extractions in the distant past experience, on average, an enhancement (typically a three to 10 percent improvement) in their ability to taste.

"The study strongly suggests that extraction of the third molar has a positive long-term, albeit subtle, effect on the function of the lingual taste pathways of some people," Kim said.

Two possibilities, the authors said, could explain the enhancement. First, extraction damage to the nerves that innervate the taste buds on the front of the mouth can release inhibition on nerves that supply the taste buds at the rear of the mouth, increasing whole-mouth sensitivity. Second, hypersensitivity after peripheral nerve injury from a surgery like an extraction has been well documented in other contexts. There is evidence, for example, from animal studies that repetitive light touch, which might occur during chewing, gradually accentuates neural responses from irritated tissue that can lead to progressive long-term tactile hypersensitivity. Whether this occurs for taste, however, is not known.

"Further studies are needed to determine the mechanism or mechanisms behind the extraction-related improvement in taste function," Doty said. "The effects are subtle but may provide insight into how long-term improvement in neural function can result from altering the environment in which nerves propagate."


Thursday, June 24, 2021

Predicting tooth loss


Machine-learning algorithms may help identify those at risk

HARVARD MEDICAL SCHOOL

Research News

Tooth loss is often accepted as a natural part of aging, but what if there was a way to better identify those most susceptible without the need for a dental exam?

New research led by investigators at Harvard School of Dental Medicine suggests that machine learning tools can help identify those at greatest risk for tooth loss and refer them for further dental assessment in an effort to ensure early interventions to avert or delay the condition.

The study, published June 18 in PLOS ONE, compared five algorithms using a different combination of variables to screen for risk. The results showed those that factored medical characteristics and socioeconomic variables, such as race, education, arthritis, and diabetes, outperformed algorithms that relied on dental clinical indicators alone.

"Our analysis showed that while all machine-learning models can be useful predictors of risk, those that incorporate socioeconomic variables can be especially powerful screening tools to identify those at heightened risk for tooth loss," said study lead investigator Hawazin Elani, assistant professor of oral health policy and epidemiology at HSDM.

The approach could be used to screen people globally and in a variety of health care settings even by non-dental professionals, she added.

Tooth loss can be physically and psychologically debilitating. It can affect quality of life, well-being, nutrition, and social interactions. The process can be delayed, even prevented, if the earliest signs of dental disease are identified, and the condition treated promptly. Yet, many people with dental disease may not see a dentist until the process has advanced far beyond the point of saving a tooth. This is precisely where screening tools could help identify those at highest risk and refer them for further assessment, the team said.

In the study, the researchers used data comprising nearly 12,000 adults from the National Health and Nutrition Examination Survey to design and test five machine-learning algorithms and assess how well they predicted both complete and incremental tooth loss among adults based on socioeconomic, health, and medical characteristics.

Notably, the algorithms were designed to assess risk without a dental exam. Anyone deemed at high risk for tooth loss, however, would still have to undergo an actual exam, the researchers added.

The results of the analysis point to the importance of socioeconomic factors that shape risk beyond traditional clinical indicators.

"Our findings suggest that the machine-learning algorithm models incorporating socioeconomic characteristics were better at predicting tooth loss than those relying on routine clinical dental indicators alone," Elani said. "This work highlights the importance of social determinants of health. Knowing the patient's education level, employment status, and income is just as relevant for predicting tooth loss as assessing their clinical dental status."

Indeed, it has long been known that low-income and marginalized populations experience a disproportionate share of the burden of tooth loss, likely due to lack of regular access to dental care, among other reasons, the team said.

"As oral health professionals, we know how critical early identification and prompt care are in preventing tooth loss, and these new findings point to an important new tool in achieving that," said Jane Barrow, associate dean for global and community health and executive director of the Initiative to Integrate Oral Health and Medicine at HSDM. "Dr. Elani and her research team shed new light on how we can most effectively target our prevention efforts and improve quality of life for our patients."

The research was done in collaboration with researchers at the Harvard T.H. Chan School of Public Health, the University of São Paolo in Brazil, and the University of Otago Faculty of Dentistry in New Zealand.

Co-investigators included André F. M. Batista, W. Murray Thomson, Ichiro Kawachi, and Alexandre D. P. Chiavegatto Filho.

This work was supported by the National Institute on Minority Health And Health Disparities (grant K99MD012253) and CNPq (grant 308731/2018-2).

Younger adults are taking medications that could affect long term oral health


Study shows dentists need to be aware of medication history even in younger patients

REGENSTRIEF INSTITUTE

Research News

INDIANAPOLIS -- A new study demonstrates that many younger adult dental patients are taking medications and highlights the importance of dental providers reviewing medication histories regardless of age.

The study from Regenstrief Institute and the Indiana University School of Dentistry looked at dental records from 11,220 dental patients over the age of 18. The results showed:

  • 53 percent of all patients reported taking at least one medication
  • 12 percent of those age 18-24 were taking at least one medication
  • 20 percent of those age 25-34 were taking at least one medication

"The number of younger adults on medication really surprised us," said senior author Thankam Thyvalikakath, DMD, PhD, director of the Regenstrief and IU School of Dentistry Dental Informatics Program. "Often dentists will assume individuals this age aren't on medications, but these results underscore the importance of paying attention to medical histories of all patients, because medications can play a significant role in oral health."

Younger adults were most likely to be taking antidepressants, which can cause dry mouth, and opioids, which carry the risk of addiction.

"We need to be aware of these possibilities, because dry mouth increases risk for tooth decay and tooth loss, and dental professionals should be proactive with preventive measures," said Dr. Thyvalikakath. "In the same way, if someone is taking an opioid, we as dentists need to make sure we are not overprescribing these medications to that patient and possibly contributing to dependence or substance use disorder."

The study showed that older patients were more likely to be taking medications to treat chronic conditions like high cholesterol, hypertension and diabetes. Across all ages, white patients were more likely to be on a medication.

In the future, Dr. Thyvalikakath hopes to develop and test an intervention to alert dental care providers about medicines and medical history because a more complete picture of a person's health can lead to better care and prevention.

"Differences in medication usage of dental patients by age, gender, race/ethnicity and insurance status" was published online ahead of print in Technology and Health Care, the official journal of the European Society for Engineering and Medicine. This project was made possible by Dr. Thyvalikakath's start-up funds through the Indiana University School of Dentistry.

Thursday, June 17, 2021

Complications following dental implant therapy are common


UNIVERSITY OF GOTHENBURG

Research News

IMAGE

IMAGE: KAROLINA KARLSSON, PHD, DENTIST SPECIALIZED IN PERIODONTICS. view more 

CREDIT: PHOTO BY UNIVERSITY OF GOTHENBURG

More than four out of ten patients who received dental implants suffered complications within a nine-year period, these are the results of a thesis presented at the University of Gothenburg.

In Sweden, more than 30 000 patients receive implant-supported restorative therapy (treatment with dental implants to replace lost teeth) on an annual basis. Good long-time results have been reported, but different types of complications can occur. These complications may affect the tissues surrounding the implant, the implant itself or the implant-supported reconstruction.

Karolina Karlsson, a dentist specialized in periodontics and a Ph.D. at the Institute of Odontology at Sahlgrenska Academy, has in her thesis evaluated the frequency, consequences, and cost of such complications.

The research was part of a national project conducted as a population-based field study. It was based on randomly selected patients from the registry of the Swedish Social Insurance Agency. Initially, dental records and radiographs from 2 765 adult patients were assessed. Of these, 596 individuals were clinically examined, nine years after their treatment with dental implants.

The results showed that 42 percent of the patients suffered from at least one complication. The most common type was technical complications, which were mostly isolated phenomena. The strongest risk factor was the extent of the implant-supported reconstruction.

Peri-implantitis, a condition characterized by inflammation in the mucosa and bone loss around the implant, was the second most common complication. Treating peri-implantitis by non-surgical methods alone, in the form of professional cleaning and instructions on oral hygiene, proved to be insufficient. Additional surgical treatment however, was able to prevent further progression of the disease.

Implant loss was the type of complication resulting in the highest total cost.

Replacing lost teeth with dental implants is a common treatment option in dentistry. It is important for care-givers and patients to have a good understanding of the individual risk for complications in order to develop effective preventive strategies.

"The results provide dental professionals and patients with important information, enabling them to evaluate and reduce the risk for complications associated with implant-supported restorative therapy," Karlsson says.

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Title: Implant-supported restorative therapy in a Swedish population: Complications and cost evaluations, http://hdl.handle.net/2077/68053