Monday, December 4, 2017

New dental material resists plaque and kills microbes

                     


Dentists rely on composite materials to perform restorative procedures, such as filling cavities. Yet these materials, like tooth enamel, can be vulnerable to the growth of plaque, the sticky biofilm that leads to tooth decay.
In a new study, researchers from the University of Pennsylvania evaluated a new dental material tethered with an antimicrobial compound that can not only kill bacteria but can also resist biofilm growth. In addition, unlike some drug-infused materials, it is effective with minimal toxicity to the surrounding tissue, as it contains a low dose of the antimicrobial agent that kills only the bacteria that come in contact with it.
"Dental biomaterials such as these," said Geelsu Hwang, research assistant professor in Penn's School of Dental Medicine, "need to achieve two goals: first, they should kill pathogenic microbes effectively, and, second, they need to withstand severe mechanical stress, as happens when we bite and chew. Many products need large amounts of anti-microbial agents to maximize killing efficacy, which can weaken the mechanical properties and be toxic to tissues, but we showed that this material has outstanding mechanical properties and long-lasting antibiofilm activities without cytotoxicity."
Hwang collaborated on the study, which was published in the journal ACS Applied Materials and Interfaces, with Penn Dental Medicine professor Hyun (Michel) Koo and Bernard Koltisko and Xiaoming Jin of Dentsply Sirona.
The newly developed material is comprised of a resin embedded with the antibacterial agent imidazolium. Unlike some traditional biomaterials, which slowly release a drug, this material is non-leachable, thereby only killing microbes that touch it.
"This can reduce the likelihood of antimicrobial resistance," Hwang said.
Hwang and colleagues put the material through its paces, testing its ability to kill microbes, to prevent growth of biofilms and to withstand mechanical stress.
Their results showed it to be effective in killing bacterial cells on contact, severely disrupting the ability of biofilms to grow on its surface. Only negligible amounts of biofilm matrix, the glue that holds clusters of bacteria together, were able to accumulate on the experimental material, in contrast to a control composite material, which showed a steady accumulation of sticky biofilm matrix over time.
Then, the team assessed how much shear force was required to remove the biofilm on the experimental material. While the smallest force removed almost all the biofilm from the experimental material, even a force four times as strong was incapable of removing the biofilm from the control composite material.
"The force equivalent to taking a drink of water could easily remove the biofilm from this material," Hwang said.
Hwang, who has an engineering background, has welcomed the opportunity to apply his unique expertise to problems in the dental field. Looking ahead, he looks forward to further opportunities to develop and test innovative products to preserve and restore oral health.

Saturday, December 2, 2017

Jawbone loss predates rheumatoid arthritis

                     


IMAGE
IMAGE: In the above x-ray image, the white dotted line indicate the normal jawbone level at a molar site in the lower jaw. The individual has periodontitis and has therefore lost... view more 
Credit: Pernilla Lundberg and Solbritt Rantapää-Dahlqvist
Jawbone loss caused by periodontitis predates the onset of rheumatoid arthritis. This according to research from Umeå University in Sweden presented in the journal Arthritis & Rheumatology. The research also shows a causal relationship between jawbone loss and elevated levels of the bone resorption inducing molecule RANKL in the blood.
Jawbone loss caused by inflammation is characteristic to both periodontitis - a disease leading to tooth loss - and rheumatoid arthritis. Despite differences in what causes the inflammation in periodontitis or rheumatoid arthritis, it has now been established that there is a correlation between the two.
"For example, it's known that individuals with rheumatoid arthritis to a great extent show symptoms of tooth loss than individuals with healthy joints. It's also been known that treatments aimed at periodontitis also ease symptoms from joints in individuals with rheumatoid arthritis. What's not been proven so far, however, is a causal relationship between the two," says Pernilla Lundberg, senior lecturer at the Department of Odontology at Umeå University, and one of the researchers behind the study.
In a collaboration, Pernilla Lundberg and Solbritt Rantapää-Dahlqvist, who is a researcher at the Department of Public Health and Clinical Medicine at Umeå University, have analysed the prevalence of jawbone loss in dental x-rays of individuals with rheumatoid arthritis. The X-rays were performed before arthritis symptoms had developed, and were compared with X-rays from matching controls. All participants in the study had on numerous occasions donated blood to the Medical Biobank Northern Sweden Health and Disease Study. Dental X-rays had been retrieved from the treating dentists.
The results, now presented in the journal Arthritis & Rheumatology, show for the first time that the individuals who later develop rheumatoid arthritis to a greater degree show signs of jawbone loss. Individuals with rheumatoid arthritis also to a greater extent develop jawbone loss over time. Among the individuals who later developed rheumatoid arthritis, the greatest degree of bone loss was detected in individuals who also showed elevated levels of the bone resorption inducing molecule RANKL in the blood.
"As far as we know, no one has previously been able to show that individuals who later develop rheumatoid arthritis have a higher degree of jawbone loss before showing any symptoms of arthritis," says Solbritt Rantapää-Dahlqvist.
"Our results indicate a causal relationship between periodontitis and rheumatoid arthritis. Nevertheless, further clinical studies and studies on basic mechanisms are needed in order to prove the existence of a causal relationship with certainty."

Monday, November 27, 2017

Immune deficiency explains rampant caries in some children

                    


Researchers at Umeå University in Sweden have made a novel discovery connecting genetic innate immunity deficiencies to rampant caries and increased risk of dental caries affecting about one in five children. The results could lead to a better way of identifying high-risk patients and treat their caries. The study has been published in the journal EBioMedicine.

In a five-year study, in which saliva and isolated bacterial strains from a large number of children was analyzed and the dental health monitored, the research group recently established that some high-risk children have a more virulent variant of the caries bacterium Streptococcus mutans. The same research group now shows that high-risk children also have genetic defects in innate and adaptive immunity, making them more vulnerable against oral bacteria and streptococci in general.

"Most people consider caries to be a lifestyle condition caused by bad eating- and oral hygiene routines that lead to acidic pH levels in the mouth, which in turn damage the enamel and promote the colonization of acid-producing bacteria such as S. mutans," says Nicklas Strömberg, professor and Head at the Department of Cariology at Umeå University and Västerbotten County Council, and first author of the article.

"Our results now show that this correlation is accurate for approximately four out of five individuals, who have a small-to-moderate risk of developing caries because their composition of salivary innate immunity proteins make them relatively resistant to caries. However, we have shown that so-called high-risk individuals, which are about one in five individuals, carry a genetically different composition of the same salivary innate immunity proteins, making them highly susceptible to caries independent of eating- or oral hygiene habits or S. mutans-infection."

One in five children in Sweden is considered a high-risk individual when it comes to the risk of developing dental caries. These high-risk individuals do not respond to traditional caries prevention or treatment, and bio markers cannot predict future risk of caries in the group. Chronic caries infection and missing teeth are also risk factors for systemic diseases such as stroke and cardiovascular diseases.

Innate and adaptive immunity deficiencies explain high-risk individuals for caries

A research group led by Nicklas Strömberg have in the current study followed 452 children (between ages 12 and 17) in Västerbotten over a five year period. After genetic analysis of their DNA, the children were divided into various risk groupings based on genetic variation in PRH1 and PRH2, encoding salivary acidic proline-rich proteins. At a five-year follow-up, the researchers could see how caries had developed in the various risk groupings.

The results showed that children with high susceptibility or risk for caries had defective proteins in their saliva. The defective salivary proteins in question were acidic and basic proline-rich proteins and the adhesive protein salivary agglutinin (or DMBT1). According to the researchers, the defective proteins probably fail to mediate the same innate and adaptive immunity responses that serve to protect individuals with small-to-moderate caries risk from the oral bacterial flora.

The researchers describe how allelic variation in PRH1 and PRH2, encoding acidic proline-rich proteins, separate children into different caries susceptibility or risk groupings. As expected, children with a low-to-moderate susceptibility or risk for caries along with a genetically intact set of proteins were found to develop caries from bad eating and oral hygiene routines and S. mutans-infection.

However, the children with high susceptibility develop caries independent of eating- or oral hygiene routines or S. mutans-infection but from the immune deficiency. Accordingly, when children were treated with dental braces the high risk children exclusively developed several times more caries after 5 years. The researchers believe this is due to plaque accumulation and impaired saliva flow as a result from the dental braces.

"This new knowledge about genetic susceptibility groupings could be used to improve individualized dental care. Children in the higher risk group could then be diagnosed before caries lesions and symptoms arise. In this way, prevention could be implemented at a young age when caries can be prevented more easily. High-risk children can presently be treated with intensified prevention and in the future we will hopefully be able to use immune-supplementation as a way to strengthen their oral immunity," explains Nicklas Strömberg.

Dental costs, including those pertaining to caries treatment, amount to 5 % of global health care-related costs. Caries is the most common cause for failure of fillings and prosthetic replacements. The ability to detect high-risk individuals early could yield large savings for society and individuals both in terms of suffering and costs.

Increased oral pathogens, decreased bacterial diversity predict precancerous stomach cancer lesions

                    


Elevated pathogen colonization and a lack of bacterial diversity in the mouth were identified in people with precancerous lesions that could precede stomach cancer, finds a new study led by New York University College of Dentistry (NYU Dentistry) and New York University School of Medicine.

The findings, published in the November issue of the Journal of Periodontology, provide new evidence that the increase in pathogens associated with periodontal disease - a chronic, destructive disease in the gums and oral cavity - could contribute to the development of precancerous lesions of stomach cancer.

"Our study reinforces earlier findings that poor oral health is associated with an increased risk of precancerous lesions of stomach cancer," said Yihong Li, DDS, MPH, DrPH, professor of basic science and craniofacial biology at NYU Dentistry and the study's corresponding author.

The American Cancer Society estimated that 26,370 new cases of stomach or gastric cancer would be diagnosed in 2016, resulting in 10,703 deaths. Accumulating evidence suggests that chronic inflammation caused by oral bacterial infections may contribute to the development and progression of various types of cancer, including stomach cancer.

Although some risk factors - such as H. pylori colonization, cigarette smoking, and eating salt and preserved foods - have previously been confirmed to contribute to the development of stomach cancer, many new cases unrelated to these risk factors are diagnosed each year. Scientists have hypothesized that a group of pathogens may be responsible for causing periodontal disease and the resulting chronic systemic inflammation that may contribute to the development of gastric cancer.

This study assesses the association between periodontal pathogen colonization and the potential risk of developing precancerous lesions - including chronic atrophic gastritis, intestinal metaplasia, and dysplasia - that may predict stomach cancer.

The researchers studied 105 individuals scheduled to receive an upper endoscopy. After the endoscopic procedure and histopathologic evaluation, 35 people were diagnosed with precancerous lesions of gastric cancer and another 70 people of the same ages without precancerous lesions were included in the study as a control group.

The researchers performed full-mouth examinations to assess participants' periodontal conditions. Saliva and dental plaque samples were collected to evaluate colonization by several of pathogens - P. gingivalis, T. denticola, T. forsythia, and A. actinomycetemcomitans - and to characterize oral microbial diversity.

Compared with the control group, patients with precancerous lesions experienced higher prevalence of bleeding when probed (31.5 percent versus 22.4 percent), higher levels of two pathogens (T. denticola and A. actinomycetemcomitans), and less bacterial diversity in their saliva.

A further analysis, which took into account sociodemographic factors, oral health behaviors, and periodontal assessments, revealed additional predictors of precancerous lesions: elevated colonization of three pathogens (T. forsythia, T. denticola, and A. actinomycetemcomitans), decreased bacterial diversity in dental plaque, and not flossing regularly.

The researchers concluded that the colonization of periodontal pathogens and the alternated bacterial diversity in the oral cavity are important factors that, when at higher or lower levels respectively, may contribute to an increased risk of developing precancerous gastric lesions.

"Based on our findings, treatment for chronic periodontal disease and control of periodontal pathogen infections should be included in future strategies for preventing stomach cancer," said Dr. Li.

Friday, November 17, 2017

Methodologies in orthodontic pain management: A review

                     


Patients experience pain and discomfort during active orthodontic treatment with fixed appliances. It can vary from person to person and is influenced by certain factors such as age, gender, previous pain experiences, stress or anxiety, and type of appliance.

The objective of this literature review was to discuss conventional versus recently introduced treatment modalities used in pain management for orthodontic patients.

According to the reviewed articles, both pharmacological and non-pharmacological methods were introduced in orthodontic pain management. However, orthodontists must use their best professional judgment to assess each case individually and select an appropriate treatment modality based on pain threshold level of an individual.

Research Key Points
  • Effective orthodontist-patient communication and targeted nutritional guidance may help in preventing pain and discomfort experienced by the patients to some extent.
  • However, based on the available literature, analgesics remained the effective and routine methodology of pain management.
  • Some clinicians supported that NSAIDs such as Ibuprofen had no impact on tooth movements as they were administered in lower doses and for a shorter duration. Hence, Ibuprofen was considered a safe and effective drug compared to other NSAIDs. On the contrary, other authors declared a delay in orthodontic tooth movements as a result of NSAID intake.
  • Another investigation supported that paracetamol (acetaminophen) was considered the safest NSAID that had no influence on the range of tooth movements as well as root resorption. However, much of what has been published on this subject is still controversial.
  • Moreover, while prescribing analgesics, orthodontists must be aware of the pharmacological action as well as the pros and cons related to each drug.
  • Nevertheless, pain management is a complex phenomenon. Therefore, further investigations combining different methods of orthodontic pain control with appropriate study designs and large sample sizes are required to improve the quality of evidence.

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For more information about the article, please visit https://benthamopen.com/ABSTRACT/TODENTJ-11-492
  • Reference: Hussain AS, et al. Methodologies in Orthodontic Pain Management: A Review. The Open Dentistry Journal, 2017, Vol 11, DOI: 10.2174/1874210601711010492

Tooth cavities can be fought 'naturally'


A new discovery may one day lead to natural anti­cavity products, researchers report.

The scientists from West China School of Stomatology and Academic Centre for Dentistry Amsterdam have figured out the main active ingredient of Galla Chinensis, a natural herb, and further improved its anti-caries efficacy. The finding is published in The Open Dentistry Journal.

To maintain a healthy mouth, the oral environment must be relatively neutral. When the environment in the mouth becomes more acidic, dental cavities or other disorders may develop. Galla Chinensis was revealed to inhibit the acid production of caries-associated bacteria as well as make teeth more resistant to acidic attack.

The research team of West China School of Stomatology has tested hundreds of Chinese herbs and identified that Galla Chinensis has a strong potential to prevent dental caries due to its antibacterial capacity and tooth mineralization benefit. Galla Chinensis also possesses substantial antiviral, anticancer, hepatoprotective, antidiarrheal and antioxidant activities. However, the main active ingredient of Galla Chinensis is unknown, which restricts the application in dentistry.

In the present study, several Galla Chinensis extracts with different main ingredients were obtained and determined by liquid chromatography-mass spectrometry (LC-MS) analysis. The antibacterial capacity was determined using the polymicrobial biofilms model, which can generate reproducible plaque-like biofilms that occur in vivo. The effect of inhibiting tooth demineralization was tested using an in vitro pH-cycling regime, which mimicked the periodic pH change in mouth.

"Medium molecular weight gallotannins are the most active constituent in terms of caries prevention" concluded Xuelian Huang, PhD, DDS, the lead author.

In dental caries, significant reductions in caries prevalence and incidence have been made by the introduction of fluoride. It is not a total cure, however, and there is still a need to seek products complementary to fluoride. With these new findings, the research team is working with the industry to develop new oral care products.
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For more information about the article, please visit https://benthamopen.com/ABSTRACT/TODENTJ-11-447
Reference: Zhou X, et al. Comparison of Composition and Anticaries Effect of Galla Chinensis Extracts with Different Isolation Methods. The Open Dentistry Journal, 2017, Vol 11, DOI: 10.2174/1874210601711010447

Naturally occurring molecule may help prevent and treat atherosclerosis and gum disease

                    

Resolvin E1, a molecule produced naturally in the body from an omega -3 fish oil, topically applied on gum tissues not only prevents and treats gum disease as previously shown (Hasturk et al 2006 and 2007), but also decreases the likelihood for advanced arterial atherosclerotic plaques to rupture and form a dangerous thrombus or blood clot.

The findings, which appear in the journal Current Atherosclerosis Reports, could lead to effective preventive and therapeutic treatments in people with heart disease and/or gum disease without unwanted side effects.

Inflammation is a key pathology of atherosclerosis and may be a major driving force for heart attacks and stroke. There is increasing evidence from numerous research groups that chronic inflammatory diseases including, diabetes, heart disease, rheumatoid arthritis, colitis, pulmonary and kidney diseases, cancer and Alzheimer's disease can benefit by the use of the pro-resolving lipid mediators, resolvins and lipoxins.

To test the effectiveness of lipid mediators on advanced atherosclerosis, researchers from Boston University School of Medicine (BUSM) and The Forsyth Institute used two groups of an experimental model that possessed highly inflamed advanced atherosclerosis.

The first group was treated with a solution applied on gum tissues that contained Resolvin E1 while the second group was treated with salt water as a control.

The group treated with the inflammation-lowering lipid mediator (Resolvin E1) had minimal atherosclerosis and reduced plaque rupture in their aortic artery, while atherosclerosis advanced to more severe form of the disease in the control (salt water) group.

"Current therapies for advanced atherosclerosis are inadequate and often carry high risks, and the Resolvin E1 therapy could provide a very effective and safe therapy that can be taken daily, which would also serve as a preventive approach for plaque inflammation and acute clinical events of heart attack and stroke," explained corresponding author James A. Hamilton, PhD, professor of physiology and biophysics and research professor of medicine at BUSM.

The researchers believe these findings support a paradigm shift in the treatment of both localized and systematic inflammatory conditions that are increasingly prevalent in type 2 diabetes and obesity and may be applicable to other chronic inflammatory diseases.


Wednesday, November 15, 2017

Treating gum disease may help lower blood pressure

                     

Treatment for gum disease, or periodontitis, significantly lowered blood pressure among Chinese patients at risk for developing high blood pressure, according to preliminary research presented at the American Heart Association's Scientific Sessions 2017, a premier global exchange of the latest advances in cardiovascular science for researchers and clinicians.

This small study compared blood pressure levels after standard and intensive treatment for gum disease. The standard treatment included basic oral hygiene instructions and teeth cleaning with plaque removal above the gum line. The intensive treatment included the standard treatment along with cleaning down to the roots with local anesthesia, antibiotic treatment and dental extractions, if necessary.

Researchers found:

  • One month after treatment, systolic blood pressure was nearly 3 points lower in participants receiving intensive treatment, but no significant difference was observed in diastolic blood pressure.
  • Three months after treatment, systolic blood pressure was nearly 8 points lower and diastolic pressure was nearly 4 points lower in patients receiving intensive treatment.
  • Six months after treatment, systolic blood pressure was nearly 13 points and diastolic blood pressure was almost 10 points lower in patients receiving intensive treatment.
"The present study demonstrates for the first time that intensive periodontal intervention alone can reduce blood pressure levels, inhibit inflammation and improve endothelial function," said study lead author Jun Tao, M.D., Ph.D., chief of the department of Hypertension and Vascular Disease and director of the Institute of Geriatrics Research at The First Affiliated Hospital of Sun Yat-sen University in Guangzhou, China.

Study participants included 107 Chinese women and men age 18 years and over with prehypertension and moderate to severe gum disease. Through random assignment, half of the participants received standard treatment and half received intensive treatment for gum disease.

Researchers noted additional research with patients from diverse backgrounds is needed.
In the United States, high blood pressure affects 29.1 percent of adults aged 18 and over in 2011 - 2012. High blood pressure is a major risk factor for heart and blood vessel disease. Fortunately, most people can manage the disease through diet and lifestyle changes, such as quitting smoking, maintaining a healthy weight, being physically active, limiting alcohol and taking prescribed medications properly.

Thursday, November 9, 2017

A focus on dental health can protect children from developing overweight

                    


Talking about dental health with children and parents - about what is healthy and unhealthy for your teeth - can be one way to prevent children from developing overweight. This is suggested in a thesis from Sahlgrenska Academy, Sweden, on children's diet, BMI and well-being.
"Weight can be a sensitive subject, but if you talk about eating behaviors alongside dental health, you're looking at the issue from a different angle," confirms Louise Arvidsson, registered dietitian and PhD student at the Institute of Medicine.
In one of her sub-studies, she reviewed eating behavior, BMI and dental health of 271 pre-school and primary school children in Sweden. The children's height, weight, and food intake over one day were compared with the prevalence of cariogenic microorganisms in saliva - and the link was clear: The children who had higher amount of caries bacteria also had significantly higher BMI and worse eating habits. They ate more frequently and consumed more foods rich in sugar.
"There is absolutely a possibility to catch these children and talk about food habits, specifically in Sweden where the dentists meets with them at an early age, but this needs a good level of collaboration between the general dentistry, the child health care and schools," says Louise Arvidsson.
With good food comes increased self-esteem, better relationships with friends and fewer emotional problems, Louise confirms in a different sub-study. Children that to a higher extent followed general dietary recommendations - wholegrain products, 400-500 grams of fruit and vegetables per day, fish two to three times a week and a low intake of sugar and saturated fat - reported better mental well-being.
The effects were achieved regardless of socio-economic background, and regardless of the children's weight. Her research further shows that good self-esteem could be linked to the healthier eating habits, two years later. A healthy diet and mental well-being might therefore be considered to interact, in a positive spiral.
"We know that adults with depression feel better if, in addition to other treatment, they also meet with a dietitian. The question is whether a healthy diet can have effect also in young children. There has been a lot of focus on physical activity and mental health in children, but diet is an increasingly recognized aspect," says Louise Arvidsson.
The entire thesis is based on data from a large European study, Idefics (with the University of Gothenburg having primary responsibility for Sweden's participation), the aim of which is to document and prevent childhood obesity.
In her thesis, Louise has also highlighted what does not work in protecting children from becoming overweight. Children between the age of 2-10 who were stopped from eating by their parents were generally overweight 5-6 years later.
"It clearly doesn't work, stopping your child from eating too much, or putting them on a diet, as some people were convinced. You really have to look at other methods to control a child's eating habits," says Arvidsson.
"Are you offering carrots as snacks, or both carrots and biscuits? What you eat at home is a very important question, and that you yourself try to make healthy choices. Children do as we do, not as we say."
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Title: Diets of European children, with focus on BMI, well-being, and families

Tuesday, November 7, 2017

Dental X-rays reveal Vitamin D deficiency



Human teeth hold vital information about Vitamin D deficiency, a serious but often hidden condition that can now be identified by a simple dental X-ray, McMaster anthropologists Lori D'Ortenzio and Megan Brickley have found.

Their research appears today in the International Journal of Paleopathology.

The researchers and their colleagues had previously discovered that human teeth hold a detailed and permanent record of serious Vitamin D deficiency, or rickets. That record takes the form of microscopic deformities in dentin, the material that makes up the mass of the tooth, and can be extremely valuable for understanding precisely when people, even those who lived centuries ago, were deprived of sunlight, the main source of Vitamin D.

The record is preserved by enamel, which protects teeth from breaking down, unlike bones, which are subject to decay.

The problem with looking for such deformities is that a tooth must be cut open to read the patterns that form a lifetime's Vitamin D record, and the supply of post-mortem teeth available for study is limited.

To avoid wasting precious specimens, the researchers went looking for a way to isolate teeth for further study. By using X-rays to study the readily observable shapes of the "pulp horns" -- the dark shadow at the centre of the image of a tooth -- they found a consistent, recognizable pattern that could prove helpful not only to their studies of archaeological teeth, but to living people who may not realize they are suffering from Vitamin D deficiency.

"We were looking for a non-destructive method so we wouldn't need to destroy precious archaeological material to see if there had been a deficiency," says D'Ortenzio, a PhD candidate in anthropology and lead author of the paper. "Now we know which teeth to look at."

The pulp shape in a healthy person's tooth resembles an arch topped by two cat ears, while the pulp shape of a person who has had a severe deficiency of Vitamin D is asymmetrical and constricted, and typically looks like the profile of a hard-backed chair.

D'Ortenzio and Brickley's previous research had suggested such a recognizable pattern, and their examination of both historic and current teeth proved that X-ray images are consistent and reliable indicators of prior deficiency.

"It was a real Eureka! It wasn't just that it looked different. It was different," says Brickley, a Professor of Anthropology who holds the Canada Research Chair in the Bioarchaeology of Human Disease. "I think it's really important. It was a piece of work that aimed to look more at past individuals, but it has the potential to contribute to modern health care as well."

Since the consequences of Vitamin D deficiency can be severe - especially in terms of bone health - knowing who has had a deficiency can help identify people who may have ongoing issues in time to prevent worse damage, the researchers say. If regular dental X-rays show a problem, blood tests can confirm whether there is an ongoing deficiency.

Such evidence could be particularly valuable in the case of children whose bones are still growing, the researchers say, and spotting a problem early could head off future problems with Vitamin-D related bone deficiency.

Knowing more about ongoing Vitamin D deficiency can also help to determine what is the best balance between protecting people from harmful UV rays and making sure they get enough sun to maintain a healthy level of the vital nutrient.

Monday, November 6, 2017

Dental filling failure linked to smoking, drinking and genetics

                     


New research shows that people who drink alcohol or men who smoke are more likely to suffer a failed dental filling. Strikingly, the research team also found that a genetic difference in some patients is associated with increased filling failure rates. The study, published today in open-access journal Frontiers in Medicine, also shows no major difference in filling failure rates between traditional amalgam and newer composite resin fillings. The results suggest that genetic analysis might help dentists to personalize treatments for their patients, which could lead to improved outcomes.

Fillings can fail for a variety of reasons, including reemergence of the initial tooth decay or the filling becoming detached. Until now, the jury has been out on whether newer composite resin fillings are as durable as traditional amalgam fillings, which have been in use for more than 150 years but which contain mercury, a toxic metal.

To investigate this, researchers from America and Brazil accessed a large repository of dental records from a dental school in Pittsburgh, which contained information on patient fillings and rates of failure up to five years after the filling procedure.

The researchers found that overall, there were no major differences between patients receiving amalgam or composite fillings in terms of filling failure rates. This suggests that composite fillings are at least as durable as amalgam fillings, and offer a viable alternative with no toxic ingredients.

The repository also contained information about patient lifestyles, including smoking and drinking habits, and a DNA sample from each patient -- allowing the team to investigate whether patient lifestyle and genetic factors could affect the failure rate of composite fillings.

The team found that within two years of the procedure, fillings failed more often in patients who drank alcohol, and the overall filling failure rate was higher in men who smoked. Furthermore, a difference in the gene for matrix metalloproteinase (MMP2), an enzyme found in teeth, was linked to increased filling failure.

The researchers hypothesize that MMP2 might be able to degrade the bond between the filling and the tooth surface, potentially leading to failure. While this link and preliminary hypothesis are intriguing, the researchers have not yet confirmed whether differences in the MMP2 gene are responsible for failed fillings, and will need to investigate this further. However, the results suggest that personal factors for each patient appear to influence their chance of filling failure, rather than the filling material their dentist used.

"A better understanding of individual susceptibility to dental disease and variation in treatment outcomes will allow the dental field to move forward," says Alexandre Vieira, a researcher involved in the study. "In the future, genetic information may be used to personalize dental treatments and enhance treatment outcomes."


Wednesday, November 1, 2017

Half of UK adults miss a quarter of their teeth when brushing

                     



Thorough tooth brushing is recognised as the foundation of good oral health regimes, and an effective way to avoid tooth decay and gum disease.
Yet a new study into the UK's tooth brushing habits released today (Wednesday 1st November 2017) reveals a disturbing trend of poor oral hygiene habits that are a major contributor to the UK's £3.4bn-plus annual bill for NHS dental treatments, and for private patients. Each week, more than 1 million patients in the UK use NHS dental services - many of them seeking treatment for dental disease, the consequences of which costs the NHS a huge £3.4bn a year.
The study, commissioned by a consortium of dentists behind Brushlink - the first smartphone 'tooth brushing tracker' that works with any toothbrush and which launches today - found that half of UK adults (48%) admit that they 'orphan' at least a quarter of the teeth in their mouth by consistently missing them when they brush.
Tooth brushing efficiency is even lower among the Millennial generation (aged 18- 34) where less than a third (29%) reach all of their teeth each time they brush compared with over half (55%) for those aged 55 and over.
In another worrying flag for the UK's oral health, the study also found that six in ten (61%) adults have never been shown how to brush their teeth correctly by a dentist or hygienist. This fact could explain why a quarter (24%) of UK adults say that someone in their household has had dental treatment in the last two years for problems they think could have been prevented by better tooth brushing and oral hygiene.
Problems like those highlighted by the report (See full results tables over) were one of the reasons why award-winning dentist Dr Dev Patel invented Brushlink - a dental coaching device and app in 2015. The device is the first that can track and coach people on brushing frequency, duration and angles while making this data available to dentists if consented - and it works with any toothbrush, manual or electric.
Brushlink has also been built to provide a brushing score each time it is used. This is displayed along with 'in-brush' coaching tips and hints via a Bluetooth connection to a smartphone app; however, it also stores data for up to three months in case the user does not have a phone in the bathroom.
Dr Dev Patel, Founder and CEO of Brushlink said:
"As a practising dentist, I have always been shocked by the lack of feedback between patient and dentist. We have always had to rely on what we see inside the mouth ever six months rather than having any reliable data about how people are brushing. I invented Brushlink to plug this gap by providing coaching to patients but also accurate monitoring of everything they are doing with their toothbrush between dentist visits."
Professor Elizabeth Kay MBE, Foundation Dean Peninsula Dental School, Oral Health Topic Expert for NICE and a Brushlink Scientific Committee member, commented:
"This survey has revealed some intriguing insights into our oral health regimes and patients' relationships with the dental health professionals who care for them. There is no substitute for good tooth brushing practices when it comes to maintaining a healthy mouth, yet it would appear from the survey that there is a lot more that we can all do to achieve this effectively.
She added: "The fact that this survey is in association with the launch of a new dental care product - and one which I think is the most amazing oral health product that I have seen in a long time - should encourage people to takes its findings seriously, as it has been commissioned by a group of dentists who are passionate about improving the oral health of the nation."

Why gum disease is associated with atherosclerosis




Heart disease and fatty clogs in the arteries go hand in hand. But new evidence suggests the fatty molecules might come not only from what you eat, but from the bacteria in your mouth, report UConn scientists in the 16 August issue of the Journal of Lipid Research. The research may explain why gum disease is associated with heart trouble.

Heart attacks and strokes are the crises we notice, but they result from a slow process of atherosclerosis, the hardening and clogging of the arteries with fatty substances called lipids. Immune cells stick to the walls of blood vessels, scavenge lipids, and multiply. The blood vessel walls inflame and thicken as the smooth muscle cells lining them change, swelling and dividing to create plaques, clogs, and warty growths called atheromas.

For a very long time, doctors and researchers assumed that the lipids came from eating fatty, cholesterol-rich food. But the research hasn't borne this out; some people who eat large amounts of the foods we thought were the sources of the fat, such as eggs, butter, fatty fish, and meat, don't necessarily develop heart disease.

UConn researchers believe they may have solved part of the puzzle. Using careful chemical analysis of atheromas collected from patients by a colleague at Hartford Hospital, they found lipids with a chemical signature unlike those from animals at all. Instead, these strange lipids come from a specific family of bacteria.

"I always call them greasy bugs because they make so much lipid. They are constantly shedding tiny blebs of lipids. Looks like bunches of grapes," on a bacterial scale, says Frank Nichols, a UConn Health periodontist who studies the link between gum disease and atherosclerosis. The bacteria, called Bacteroidetes, make distinctive fats. The molecules have unusual fatty acids with branched chains and odd numbers of carbons (mammals typically don't make either branched chain fatty acids or fatty acids with odd numbers of carbons).

Xudong Yao, a UConn associate professor of chemistry who analyzed the lipid samples, says the chemical differences between bacterial and human lipids result in subtle weight differences between the molecules. "We used these weight differences and modern mass spectrometers to selectively measure the quantity of the bacterial lipids in human samples to link the lipids to atherosclerosis," he says. "Establishment of such a link is a first step to mark the lipids as indicators for early disease diagnosis."

The marked chemical differences between Bacteroidetes lipids and the human body's native lipids may be the reason they cause disease, suggests Nichols. The immune cells that initially stick to the blood vessel walls and collect the lipids recognize them as foreign. These immune cells react to the lipids and set off alarm bells.

Nichols and Yao's team also showed that despite being non-native lipids, the Bacteroidetes lipids could be broken down by an enzyme in the body that processes lipids into the starting material to make inflammation-enhancing molecules. So the Bacteroidetes lipids have a double whammy on the blood vessels: the immune system sees them as a signal of bacterial invasion, and then enzymes break them down and super-charge the inflammation.

Despite the havoc they wreak, it's not the Bacteroidetes bacteria themselves invading. Usually these bacteria stay happily in the mouth and gastrointestinal tract. If conditions are right, they can cause gum disease in the mouth, but not infect the blood vessels. But the lipids they produce pass easily through cell walls and into the bloodstream.

The next step in the research is to analyze thin slices of atheroma to localize exactly where the bacterial lipids are accumulating. If they can show the Bacteroidetes-specific lipids are accumulating within the atheroma, but not in the normal artery wall, that would be convincing evidence that these unusual lipids are associated specifically with atheroma formation, and therefore contribute to heart disease.

Friday, October 27, 2017

Flexible batteries a highlight for smart dental aids



IMAGE
IMAGE: Flexible lithium batteries have been incorporated into dental braces as part of efforts to increase the efficiency of corrective orthodontics. view more 
Credit: © 2017 KAUST
Smart 3D-printed braces that incorporate nontoxic batteries and lights could reduce the time and costs involved in realigning and straightening teeth.

The orthodontic system, conceptualized by researchers at KAUST, involves placing two near-infrared light-emitting diodes (LEDs) and one lithium-ion battery on every tooth in a semitransparent, 3D-printed dental brace.

The batteries provide energy to turn the near-infrared LEDs on and off, depending on how they are programmed by a dentist, to provide localized light therapy according to the needs of each tooth. Phototherapy enhances bone regeneration and can reduce the time and costs involved in corrective orthodontics. The brace would be removable to allow the batteries to be recharged.

"We started embedding flexible LEDs inside 3D-printed braces, but they needed a reliable power supply," explains Muhammad Hussain who led the study together with PhD student Arwa Kutbee. "After the incidents with the Samsung Galaxy 7 batteries exploding, we realized that traditional batteries in their current form and encapsulation don't serve our purpose. So we redesigned the state-of-the-art lithium-ion battery technology into a flexible battery, followed by biosafe encapsulation within the braces to make a smart dental brace."

The battery was redesigned using a dry-etching technique, which removes the silicon substrate normally found on its back. This process thinned the battery to 2.25mm x 1.7mm and made it flexible. Tests showed that the volumetric energy -- the ratio of energy to device size--of the redesigned batteries remained high even after many cycles of continuous operation.

Batteries were then encapsulated in biocompatible soft polymeric materials to prevent the possibility of leakage, making them safe to place in the mouth. As a testament to their biocompatibility, when human embryonic kidney cells were cultured on these batteries over a period of days, they thrived and proliferated. The batteries' electrochemical performance increased linearly with rising temperature, up to 90°C, making them stable.

Hussain says the system is a preliminary prototype, "which is more than a proof of concept." The next step, he says, is to conduct clinical trials.

Triclosan accumulates in toothbrushes, potentially prolonging users' exposure


In September, a ban on triclosan in over-the-counter antiseptic soaps, gels and wipes went into effect in the U.S. But the antibacterial ingredient is still allowed in toothpastes for its reported ability to reduce gum inflammation, plaque and cavities. Now a study in ACS' Environmental Science & Technology has found that triclosan accumulates in toothbrush bristles and elastomer parts, and is readily released when users switch toothpastes, potentially prolonging users' exposure to the compound.

Past research has demonstrated that triclosan has the potential to disrupt hormones in animals and humans, contribute to antibiotic resistance and cause acute toxicity to aquatic organisms. In light of the reported adverse effects and the lack of scientific evidence on its benefits over plain soap and water, the U.S. Food and Drug Administration banned triclosan in antiseptic washes. However, the ruling doesn't apply to toothpaste and other products, including clothing and cookware.

Jie Han, Wei Qiu, Baoshan Xing and colleagues suspected that triclosan might stick to materials commonly used on commercial toothbrush heads and get released in an uncontrolled manner, creating a hidden route of exposure and transport of the chemical that hadn't been previously considered.


The researchers simulated toothbrushing with a range of commercial brushes and pastes. Their testing showed that more than one third of the 22 toothbrushes tested, including two children's varieties, accumulated significant amounts of triclosan equivalent to seven to 12 doses of the amount used per brushing. Toothbrushes with "polishing cups" or "cheek/tongue cleaners," typically made of a class of materials called elastomers, absorbed the largest amounts.

When the researchers switched to triclosan-free toothpastes but continued to use the same brushes, triclosan was continuously released from the toothbrushes over the next two weeks. This release could lead to a user receiving prolonged exposure to triclosan, and potentially to other transformation products that previously hadn't been accounted for, even after switching toothpastes. Additionally, regular landfill disposal of used toothbrushes that have accumulated triclosan could result in the chemical leaching into the environment. The study also raises broader questions about the design of consumer products -- particularly those used for personal care -- with absorptive polymer components that are regularly exposed to chemicals during use.

Wednesday, October 25, 2017

Antimicrobial gel could improve root canal results


More than 15 million root canals are done each year, according to the American Association of Endodontists. During the procedure, the tooth's pulp and nerve are removed before the tooth is cleaned and sealed. If bacteria, viruses or yeasts contaminate the tooth, another root canal procedure or surgery must be done.

Now, the results of root canal treatments could improve because of an antimicrobial gel discovered and developed at the Indiana University School of Dentistry.

Ghaeth H. Yassen, a visiting assistant professor, has developed an injectable antimicrobial gel that could disinfect a tooth during a root canal procedure.

"I wanted to create a gel that provides sustained antimicrobial properties even when it is removed. I also wanted it to have minimal toxic effect on stem cells and not cause tooth discoloration," he said. "Creating an antimicrobial space is especially important during clinical regenerative endodontic procedures."

Yassen said the gel has advantages over traditional medications, including calcium hydroxide, widely used as an antibacterial agent.

"The gel offers extended and significantly longer residual antibacterial properties, which has been demonstrated in papers published in the Journal of Endodontics and the International Endodontic Journal," he said. "It is biocompatible, and it contains a low concentration of antimicrobial elements."
Yassen said the next steps include optimizing a version of the gel that is opaque to X-rays and other radiation, which will enable dental care professionals to track it within the root canal system.

Monday, October 23, 2017

Better food choices for healthier teeth

.A team of Montréal researchers, including Dr. Tracie Barnett of INRS, took a look at schools in Greater Montréal to see how oral health was being promoted and what incidence this had on cavity rates in children. Published in the American Journal of Preventive Medicine, this study concluded that prevention programs are important, but that school food environments play a leading role in the appearance of cavities in kids ages 8 to 10.

Food choices in and around schools vary greatly and affect the general health of children. It's an environment often carefully observed to understand its impact on obesity prevalence, but rarely in relation to cavities. The data gathered for the QUALITY study (family study on the prevention of cardiovascular disease and Type 2 diabetes in kids and teens) was ideal for verifying children's dental health.

Over a period of two years, the research team analyzed various factors affecting 330 students at 200 schools, including socioeconomic factors, school food environments, and cavity prevention programs. According to their findings, programs promoting healthy eating and good dental hygiene had a positive but relatively modest impact compared to children's food and socioeconomic environments.

Because cavities remain a public health concern, the researchers suggest making this component part of health promotion programs alongside obesity. Policies promoting healthy eating environments could have a greater impact on children's oral health than school programs run in isolation to encourage kids to take good care of their teeth.

Saturday, October 7, 2017

Dentists can harvest stem cells



  • Dr. Karl Kingsley and Dr. James Mah, research professors with the UNLV School of Dental Medicine.
  • Credit: Josh Hawkins/UNLV Creative Services

Stem cells. Few research discoveries hold as much promise of single-handedly expanding medical treatment options as they do. Miraculously able to act as transformers—either re-creating or morphing into a variety of cell types found within the organisms they originate from—stem cells offer humanity hope for new, more effective therapies against a number of chronic and terminal diseases. And finding them is surprisingly easy.
“Stem cells can be extracted from nearly any living tissue,” said Dr. James Mah, director of UNLV’s advanced education program in orthodontics, doctor of dental surgery, and dental researcher. “In fact, stem cells can even be found in tissues of the deceased.”
But in spite of all their potential, there’s a catch: “The biggest challenges with stem cells are gathering enough of them to work with and keeping them viable until they are needed,” Dr. Mah said.
He and UNLV biomedical sciences professor Karl Kingsley—along with a handful of undergraduate, graduate, and postdoctoral dental students—decided to take on this challenge, cutting their teeth in stem cell research by exploring those pearly whites in new ways. In the process, they developed a new method for extracting large numbers of stem cells they could then preserve from a surprisingly abundant source: wisdom teeth.
“More and more adults—approximately 5 million throughout the country—have their wisdom teeth, or third molars, removed,” Kingsley said. “Extracting teeth is relatively common among patients undergoing orthodontic treatments. And the majority of those teeth are healthy, containing viable tooth root pulp that offers opportunities for reproducing cells that have been damaged or destroyed by injuries or disease.”

A tough nut to crack

Tooth root pulp is home to two types of prized stem cells. The first, pluripotent stem cells, have the ability to become any cell in the organism from which they’re drawn. The second, multipotent stem cells, transform into specific types of cells within that organism.
Knowing where to find these cells was one thing. Recovering them, the researchers knew, would be another.
Common methods for extracting root pulp involve drilling into, removing the top of, or shattering the tooth. Each method has its detriments, Dr. Mah said, all of which lead to a low stem-cell recovery rate: damaging heat from drilling, corrosive elements in the water teeth are rinsed in, contaminating enamel particulates, and more. So the researchers sought to discover how to extract pulp in a manner that consistently produced a higher yield.
“Initially, the answer seemed simple: crack the tooth in half like a nut and remove the pulp,” Dr. Mah said.
Unfortunately, teeth have irregular surfaces and non-uniform shapes, so cracking teeth usually produces the same shattering effect as a hammer, thereby reducing the number of viable stem cells.
Happy Ghag, then a dental student working with Dr. Mah and Kingsley on the project, thought he might have solution to the dilemma. He approached Mohamed Trabia (UNLV Howard R. Hughes College of Engineering’s associate dean for research, graduate studies, and computing) and Brendan O’Toole (Mendenhall Innovation Program director and mechanical engineering researcher) to discuss fracture analysis.
“Happy had reviewed fracture mechanics literature and decided on a technique that scored the tooth to enable a clean break, similar to the process for custom-cut glass,” O’Toole said. After a few discussions, some of Engineering’s personnel helped Ghag fabricate the device.
The completed instrument, which the research team facetiously dubbed the “Tooth Cracker 5000,” uses a clamp to hold a tooth in position for a cutting tool to score the surface and a blade to crack it. The result: a perfectly halved tooth, with immediate access to undamaged and uncontaminated root pulp.
For O’Toole, this was just another successful collaboration between the two units, as Mechanical Engineering had been interacting with the School of Dental Medicine’s orthodontic program for a few years.
“Orthodontics, by definition, is a bioengineering topic,” O’Toole said. “They design and place mechanisms in people’s mouths that help move teeth into optimum position. The interaction between our departments makes a lot of sense.”
With the Tooth Cracker 5000 complete, Dr. Mah and Kingsley tested the fracture rate of 25 teeth, achieving a 100 percent rate of success. The fracture idea and design prototype had worked perfectly.

Excavating for success

Now that the researchers had cracked the challenge of accessing the root pulp, it was on to determining how many viable stem cells they could recover from the fractured teeth. Average pulp recovery rates employing common extraction methods (i.e., shattering, drilling, etc.) come in at around 20 percent, Dr. Mah noted.
It was time to test the mettle of their new fracture method. Dr. Mah and Kingsley dyed 31 fractured teeth pulp samples to highlight any viable stem cells the teeth contained. Dead cells would turn blue when exposed to the dye. Living cells would appear clear.
They looked under the microscope. Eighty percent of their extracted cells remained clear after the dye was introduced.
“Saying the test results were promising is a gross understatement,” Dr. Mah said. “We realized we’d invented an extraction process that produced four times the recovery success rate for viable stem cells. The potential application is enormous.”

Replicating for a rainy day

After mastering fracturing and extraction, it was time for the team to determine what kind of stem cells could be harvested and how best to store them.
Normal cells within the body typically die after 10 replications or passages, whereas stem cells can replicate indefinitely, Kingsley indicated. To isolate the stem cells from the rest of the root pulp, the researchers harvested cells from the pulp and cultured them on a petri dish. Once the cells covered the dish, they split the culture in half and repeated the process between 10 and 20 times.
By the end of the culturing, all nonstem cells had expired. Kingsley captured the remaining stem cells and collected their ribonucleic acid (RNA), which is converted into proteins that become biomarkers his team could use to characterize each stem cell type and its respective rate of replication.
“Scientists around the world are trying to figure out what type of stem cells can be coaxed into becoming new cells or different tissue types,” Kingsley said. “We already know some populations of dental pulp stem cells can be converted into neurons, which could become therapies for cognitive diseases such as Alzheimer’s or Parkinson’s.”
Kingsley noted that teams of scientists around the world are working with animal models to test using stem cells to treat neurological conditions. Early indications, he said, are positive. Although there is still a need for additional tests, Kingsley indicated that the next logical step in this research would be to test stem cells in humans to treat any number of chronic illnesses people face.
“There are potential applications of stem cells for multiple diseases, including cancer, arthritis, and lung disease,” Kingsley said. “The next challenge is reliably collecting the stem cells early enough and storing them successfully so they can be used when needed.”

Preserving the prize

According to multiple studies, the number of pluripotent stem cells found in teeth decrease dramatically after adults reach the age of 30, Kingsley said. However, people could donate stem cells found in their teeth much like they may donate their blood prior to a surgical procedure or preserve their umbilical cords. If people elected to have their wisdom teeth removed or were having a root canal performed, their stem cells could be harvested at that time and stored for future use.
Creating that possibility has led Dr. Mah and Kingsley to the next step in their research: the cryogenic process.
“There is no standard cryogenesis, or freezing process, for storing stem cells,” Kingsley said. “There are multiple organizations that collect and freeze teeth for future studies and use, but there is no evidence about the long-term effects of cryopreservation. We can’t answer yet just how long the cells will survive.”
In 2011 dental student Allison Tomlin studied different populations of stem cells and their viability after being thawed. Every year since, Kingsley and his team have thawed a portion of Tomlin’s sample and evaluated the viability of remaining stem cells. Initial findings—which Kingsley, Tomlin, and R. Michael Sanders (clinical sciences professor in the dental school) published in their Biomaterials and Biomechanics in Bioengineering article “The Effects of Cryopreservation on Human Dental Pulp-derived Mesenchymal Stem Cells”—indicate that rapidly dividing cells have higher rates of viability year after year compared to slower dividing cells. If these results remain constant, the stem cells could be sorted before the freezing process based on when they might be needed.
“The work Dr. Kingsley and I are doing is part of a paradigm shift,” Dr. Mah said. “Our fracturing process could hasten the collection and cryogenesis process, thereby preserving a high stem-cell count that furthers research into how using these cells can aid healing and potentially cure diseases.”

Friday, October 6, 2017

Antibiotics for dental procedures linked to superbug infection, study shows

                    

Antibiotics prescribed by dentists may contribute to the growing problem of Clostridium difficile (C. diff), a serious and potentially deadly infection that causes severe diarrhea, suggests research presented at IDWeek 2017. And many of those antibiotics are likely unnecessary, researchers note.

Taking antibiotics can put patients at risk for developing C. diff and illustrates the importance of using the medications only when needed. The Minnesota Department of Health (MDH) tracked community-associated C. diff infections - meaning those in patients who did not have an overnight stay in a hospital or nursing home - in five counties in the state. During the six-year period, researchers determined 15 percent of those with the infection who had taken antibiotics had them prescribed for dental procedures.

But one-third of those patients' medical charts included no mention of receiving dental procedure-related antibiotics, researchers determined. An earlier survey conducted by the MDH found 36 percent of dentists prescribed antibiotics in situations that are generally not recommended by the American Dental Association (ADA) and reported challenges to making appropriate antibiotic prescribing decisions, including confusion about or perceived conflicts among prescribing guidelines.

"Dentists have been overlooked as a source of antibiotic prescribing, which can potentially delay treatment when doctors are trying to determine what is causing a patient's illness," said Stacy Holzbauer, DVM, MPH, lead author of the study and career epidemiology field officer for the CDC and MDH. "It's important to educate dentists about the potential complications of antibiotic prescribing, including C. diff. Dentists write more than 24.5 million prescriptions for antibiotics a year. It is essential that they be included in efforts to improve antibiotic prescribing."

Dentists appropriately prescribe antibiotics in certain situations, such as to treat infections stemming from a tooth abscess. However, some dentists prescribe antibiotics prophylactically before a dental procedure to prevent a heart infection in patients with heart conditions, or to prevent an infection of an artificial joint, such as a hip or knee replacement. The ADA no longer recommends preventive antibiotics in most of those cases, as it once did.

"It is possible some dentists aren't aware of the updated recommendations or are being asked by other healthcare providers to continue preventive antibiotics despite the change," said Dr. Holzbauer. Current recommendations note the risk of taking antibiotics - such as developing C. diff - is greater than the risk of an infection in those cases. Further, the inappropriate use of antibiotics helps fuel the creation of drug-resistant bacteria, which are very difficult to treat and are an increasing public health threat.

In the study, MDH researchers interviewed 1,626 people with community-associated C. diff between 2009 and 2015. Of those, 926 (57 percent) reported they had been prescribed antibiotics, 136 (15 percent) of those for dental procedures. The study found patients who were prescribed antibiotics for dental procedures tended to be older and more likely to receive clindamycin, an antibiotic that is associated with C. diff infection. Of those who had received antibiotics for a dental procedure, 34 percent had no mention of antibiotics in their medical charts, illustrating the disconnect between dental and medical care. During routine medical appointments, patients should bring up dental visits and medications, including antibiotics - they have taken. In addition, healthcare providers should ask patients about dental visits and medications taken for dental reasons.

Antibiotics kill bad and good bacteria in the gastrointestinal (GI) system. Wiping out the protective bacteria can allow the growth of C. diff bacteria, leading to severe and potentially deadly diarrhea. C. diff can occur after just one dose of antibiotics and is one of the top three most urgent antibiotic-resistant threats identified by the CDC. It caused almost half a million infections and led to 15,000 deaths in a single year, according to CDC estimates.

"Research has shown that reducing outpatient antibiotic prescribing by 10 percent could decrease C. diff rates outside of hospitals by 17 percent," said Dr. Holzbauer. "Limiting the use of inappropriate antibiotics in dentistry could also have a profound impact."

While the ADA has expressed a commitment to and is an active partner in antibiotic stewardship, a 2015 MDH survey of dentists found fewer than half were concerned about adverse drug effects, antibiotic resistance or C. diff as factors that influenced their prescribing decisions. That's likely because they are unaware when their patients develop C. diff, Dr. Holzbauer said. Better communication between dental and medical communities and improved history taking by all prescribers would help, she said.


Monday, September 25, 2017

Chronic migraine cases are amplified by jawbone disorder

                     


In a study, researchers at the University of São Paulo's Ribeirão Preto School of Medicine (FMRP-USP), in Brazil, finds that the more frequent the migraine attacks, the more severe will be the so-called temporomandibular disorder, or TMD. The temporomandibular joint acts like a sliding hinge connecting the jawbone to the skull, therefore the disorder's symptoms includes difficulty chewing and joint tension.
"Our study shows that patients with chronic migraine, meaning attacks occurring on more than 15 days per month, are three times as likely to report more severe symptoms of TMD than patients with episodic migraine," said Lidiane Florencio, the first author of the study, which is part of the Thematic Project "Association study of clinical, functional and neuroimaging in women with migraine", supported by the São Paulo Research Foundation - FAPESP.
Previous studies already indicated that migraine is somehow associated with pain in the chewing muscles. However, this research was the first to consider the frequency of migraine attacks when analyzing its connection with TMD: eighty-four women in their early to mid-thirties were assessed, being that 21 were chronic migraine patients, 32 had episodic migraine, while 32 with no history of migraine were included as controls - the results were published in the Journal of Manipulative and Physiological Therapeutics.
Signs and symptoms of TMD were observed in 54% of the control participants without migraine, 80% of participants with episodic migraine, and 100% of those with chronic migraine.
For Florencio, central sensitization may explain the association between the frequency of migraine attacks and the severity of TMD.
"The repetition of migraine attacks may increase sensitivity to pain," she said. "Our hypothesis is that migraine acts as a factor that predisposes patients to TMD. On the other hand, TMD can be considered a potential perpetuating factor for migraine because it acts as a constant nociceptive input that contributes to maintaining central sensitization and abnormal pain processes." Nociceptive pain is caused by a painful stimulus on special nerve endings called nociceptors.
Migraine and TMD have very similar pathological mechanisms. Migraine affects 15% of the general population, and progression to the chronic form is expected in about 2.5% of migraine sufferers. On the other hand TMD is stress-related as much as it has to do with muscle overload. Patients display joint symptoms - such as joint pain, reduced jaw movement, clicking or popping of the temporomandibular joint - but also develop a muscular condition, including muscle pain and fatigue, and/or radiating face and neck pain.
Which came first?
TMD and migraine are comorbidities. However, while people who suffer from migraine are predisposed to have TMD, people with TMD will not necessarily have migraine.
"Migraine patients are more likely to have signs and symptoms of TMD, but the reverse is not true. There are cases of patients with severe TMD who don't present with migraine," said Débora Grossi, the lead researcher for the study and principal investigator for the Thematic Project.
The researchers believe that TMD may increase the frequency and severity of migraine attacks, even though it does not directly cause migraine.
"We do know migraine isn't caused by TMD," Florencio said. "Migraine is a neurological disease with multifactorial causes, whereas TMD, like cervicalgia - neck pain - and other musculoskeletal disorders, is a series of factors that intensify the sensitivity of migraine sufferers. Having TMD may worsen one's migraine attacks in terms of both severity and frequency."
The journal article concludes that an examination of TMD signs and symptoms should be clinically conducted in patients with migraine.
"Our findings show the association with TMD exists but is less frequent in patients with rare or episodic migraine," Grossi said. "This information alone should change the way clinicians examine patients with migraine. If migraine sufferers tend to have more severe TMD, then health professionals should assess such patients specifically in terms of possible signs and symptoms of TMD."

Thursday, September 14, 2017

Don't blame your genes for your toothache, twin study shows

                     


For the first time, investigators have looked at the role that genes and the oral microbiome play in the formation of cavities and have found that your mother was right: The condition of your teeth depends on your dietary and oral hygiene habits. The study appears September 13 in Cell Host & Microbe.

"Limiting sugar consumption and acid buildup in the mouth have been part of the dogma of the dental community for some time," says senior author Karen Nelson, President of the J. Craig Venter Institute (JCVI). "This work introduces specific taxa of bacteria that can be acquired through the environment and that have the ability to induce cavities."

Since the early 20th century, dentists and other experts have known that Streptococcus bacteria in the mouth are linked to the formation of cavities. Now, with the ability to study studying the microbiome, the investigators were able to take a closer look at specific taxa that are important.

To separate the role of heritability versus the environment, Nelson and her team turned to a popular method for studying such interactions: identical and fraternal twins. Specifically, they profiled the oral microbiomes of 485 twin pairs between the ages of 5 and 11. There were 280 fraternal twins and 205 identical twins--and one set of triplets. The samples were obtained with mouth swabs.

"We decided to focus on children because we hypothesized twow things--that the oral microbiome rapidly changes with age, and also that child twin pairs are likely to have a shared environment," Nelson says. "This allowed us to better control the influence of shared and unique environments."

Their results--driven with significant analysis input from co-authors Josh Espinoza (JCVI Engineer) and Chris Dupont (JCVI Associate Professor)--showed that identical twins had oral microbiomes that were more similar to each other than those of fraternal twins, indicating that there is genetic contribution to which kinds of bacteria are likely to be present in the mouth. However, the taxa that were linked most closely to heritability were not the ones that play a role in cavity formation. In addition, they found that the heritable strains of bacteria decrease in abundance as people get older, whereas the ones linked to the environment increase.

An important additional finding was the link between certain bacterial species and sugar consumption. Bacteria that were associated with fewer cavities were in lower abundance in twins who had a lot of added sugar in their food and drinks. In contrast, bacteria that are more common in children who consume a lot of sugar were associated with having more cavities.

The team plans to continue studying the twins over repeat visits to examine changing patterns in the oral microbiome. They are also looking at functional differences in the oral microbiomes of identical and fraternal twin pairs that have various states of oral health.
  

Friday, September 8, 2017

Many middle-aged adults report dental pain, embarrassment and poor prevention


The dental health of middle-aged Americans faces a lot of problems right now, and an uncertain future to come, according to new results from the University of Michigan National Poll on Healthy Aging.

One in three Americans between the ages of 50 and 64 say they're embarrassed by the condition of their teeth. A slightly larger percentage say dental problems have caused pain, difficulty with eating, missed work or other health problems in the past two years. Forty percent of those polled don't get regular cleanings or other preventive care that can help prevent dental problems.

Insurance coverage appears to have a lot to do with this lack of care. Overall, 28 percent of respondents said they don't have dental coverage. But that percentage was much higher -- 56 percent -- among those who say they only seek care for serious dental problems.

As for the future, 51 percent of those surveyed said they simply didn't know how they will get dental insurance coverage after they turn 65.

Another 13 percent of middle-aged adults expect to count on Medicare or Medicaid to cover their oral care needs after that age. Traditional Medicare does not cover routine dental care, and Medicaid dental coverage is often limited.

The poll, based on a nationally representative sample of older adults, was conducted by the U-M Institute for Healthcare Policy and Innovation with support from AARP and Michigan Medicine, U-M's academic medical center.

"Our findings highlight a stark divide among middle-aged Americans in terms of their oral health now, and a real uncertainty about how they will get and pay for care as they age," says associate poll director Erica Solway, Ph.D. "This is not out of disregard for the importance of preventive dental care - more than three-quarters of the people we polled agree that regular care is important to preventing problems later. But it does highlight opportunities to improve access to care and insurance options after age 65."

Solway and poll director Preeti Malani, M.D., a professor of internal medicine at the U-M Medical School, divided the poll respondents into three groups based on their responses about their use of dental care:
  • prevention-focused: about 60 percent of the sample, who got regular preventive care as well as getting attention for dental problems
  • inconsistent prevention: the 17 percent who sought preventive dental care occasionally
  • problem-only: the 23 percent who went to the dentist only for serious dental problems.
"We know that oral health is a critical factor in overall wellness, and this research helps us identify some key issues - such as affordability and coverage - that we can focus on to address those 40% who are not prevention-focused," stated Dr. Alison Bryant, Senior Vice President of Research for AARP.

A clear divide
Poll respondents who were female, white, had higher incomes or had insurance were much more likely than others to take a prevention-focused approach to dental care. Men, African Americans, Hispanics, those with lower income, or those without insurance were more likely to seek dental care for problems only.

The differences among the three groups was also apparent when the U-M team asked about how easy it was to get care, and why they might not have sought care.

Among those who were prevention-focused, only 13 percent said they had delayed or hadn't received dental care when they needed it in the last two years. But that jumped to 35 percent in the inconsistent-prevention group, and 56 percent in the problem-only group.

Why didn't poll respondents get needed dental care? Cost was the most commonly reported answer, given by 69 percent who said they did not get or delayed needed care. Respondents also reported they were afraid of the dentist, couldn't find time to go, or couldn't find a dentist. Of the people who didn't receive care they needed, one in five cited fear of the dentist as a major factor.

Uncertain future
Looking ahead to the years beyond their 65th birthday - an age when most Americans become eligible for Medicare- the poll respondents were uncertain about how they'd get dental insurance.
Some - 16 percent - said they counted on employer-based coverage or a retirement-based plan. Another 12 percent said they planned to buy supplemental dental insurance.

And in addition to the half of respondents who indicated that they didn't know whether they will have dental insurance at all after age 65, another eight percent said they'd just go without it.

But it's the remaining respondents - the 13 percent who expect Medicare or Medicaid to cover their dental care in their older years - that concern the poll leaders the most.

"Traditional Medicare does not cover dental care, and many states offer very limited or no dental coverage for adults with Medicaid," says Malani. "Even those who were diligent about seeing the dentist and had dental insurance throughout adulthood may find it harder to afford dental care as they get older and coverage options may be more limited."

The nationally representative sample included 1,066 people ages 50 to 64, who answered a wide range of questions online; laptops and Internet access were provided to those who did not already have it.
###
A full report of the findings and methodology is available at http://www.healthyagingpoll.org.

New dental imaging method uses squid ink to fish for gum disease



Squid ink might be a great ingredient to make black pasta, but it could also one day make getting checked for gum disease at the dentist less tedious and even painless. By combining squid ink with light and ultrasound, a team led by engineers at the University of California San Diego has developed a new dental imaging method to examine a patient's gums that is non-invasive, more comprehensive and more accurate than the state of the art.

"The last time I was at the dentist, I realized that the tools that are currently being used to image teeth and gums could use significant updating," said Jesse Jokerst, a nanoengineering professor at UC San Diego and senior author of the study.

The conventional method for dentists to assess gum health is to use an instrument called a periodontal probe -- a thin, hook-like metal tool that's marked like a tiny measuring stick and inserted in between the teeth and gums to see whether and how much the gums have shrunk back from the teeth, creating pockets. This method of measuring pocket depth is the gold standard used in dentistry. A pocket depth measuring one to two millimeters indicates healthy gums while three millimeters and deeper is a sign of gum disease. The deeper the pockets, the more severe the gum disease.

However, procedures using the periodontal probe are invasive, uncomfortable and sometimes painful for the patient. Measurements can also vary greatly between dentists, and the probe is only capable of measuring the pocket depth of one spot at a time.

In a paper published on Sept. 7 in the Journal of Dental Research, Jokerst and his team at UC San Diego introduced an innovative method that can image the entire pocket depth around the teeth consistently and accurately, without requiring any painful poking and prodding.

"Using the periodontal probe is like examining a dark room with just a flashlight and you can only see one area at a time. With our method, it's like flipping on all the light switches so you can see the entire room all at once," Jokerst said.

The method begins by rinsing the mouth with a paste made of commercially available food-grade squid ink mixed with water and cornstarch. The squid-ink-based rinse serves as a contrast agent for an imaging technique called photoacoustic ultrasound. This involves shining a light signal -- usually a short laser pulse -- onto a sample, which heats up and expands, generating an acoustic signal that researchers can analyze. "Light in, sound out," Jokerst said.

Squid ink naturally contains melanin nanoparticles, which absorb light. During the oral rinse, the melanin nanoparticles get trapped in the pockets between the teeth and gums. When researchers shine a laser light onto the area, the squid ink heats up and quickly swells, creating pressure differences in the gum pockets that can be detected using ultrasound. This method enables researchers to create a full map of the pocket depth around each tooth -- a significant improvement over the conventional method.

Researchers tested their photoacoustic imaging method in a pig model containing a mix of shallow and deep pockets in the gums. While their results closely matched measurements taken using a periodontal probe, they were also consistent across multiple tests. On the other hand, measurements with the periodontal probe varied significantly from one test to another.

"It's remarkable how reproducible this technique is compared to the gold standard," Jokerst said.
Moving forward, the team will be collaborating with dentists and testing their method in humans. Future work also includes minimizing the taste of the squid ink oral rinse -- it's salty and somewhat bitter -- and replacing laser lights with inexpensive, more portable light systems like LEDs. The team's ultimate goal is to create a mouthpiece that uses this technology to measure periodontal health.