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.
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.
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.
