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.
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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.

Tuesday, August 22, 2017

A new dental restoration composite more durable than the conventional material



Fewer trips to the dentist may be in your future, and you have mussels to thank.

Inspired by the mechanisms mussels use to adhere to inhospitable surfaces, UC Santa Barbara researchers have developed a new type of dental composite that provides an extra layer of durability to treated teeth. The potential payoff? Longer lasting fillings, crowns, implants and other work.
"It's as hard as a typical dental restoration but less likely to crack," Kollbe Ahn, a materials scientist at UCSB's Marine Science Institute, said of the composite. The research is highlighted in the journal Advanced Materials. The paper, of which Ahn is the corresponding author, is the result of collaboration between research and industry.

On average, a dental restoration lasts five to 10 or so years before needing replacement. The time frame depends on the type of restoration and how well the patient cares for the treated tooth. However, the continual onslaught of chewing, acidic and hard foods, poor hygiene, nighttime tooth grinding, generally weak teeth and even inadequate dental work can contribute to a filling's early demise -- and another expensive and possibly less-than-pleasant experience in the dental chair.

According to Ahn, one of the primary reasons restorations fall out or crack is brittle failure of the bond with the surrounding tooth. "All dental composites have micro-particles to increase their rigidity and prevent their shrinkage during their curing process," he explained. "But there's a trade-off: When the composite gets harder, it gets more brittle."

With enough pressure or wear and tear, a crack forms, which then propagates throughout the entire restoration. Or, the gap between the tooth and the restoration results in restoration failures, including marginal tooth decay.

So Ahn and his colleagues looked to nature -- mussels, to be exact -- to find a way not only to maintain strength and hardness but also to add durability. Having perfected the art of adhering to irregular surfaces under the variable conditions of the intertidal zone -- evolving to resist pounding waves, the blazing heat of the sun and cycles of salt water immersion and windy dryness -- mussels presented the ideal model for more durable dental restoration materials. The byssal threads they use to affix to surfaces allow them to resist the forces that would tear them from their moorings.

"In nature, the soft collagenous core of the mussel's byssal threads is protected by a 5-to-10 micrometer thick, hard coating, which is also extensible and thus, tough," Ahn said. This durability and flexibility allow the mollusks to stick to wet mineral surfaces in harsh environments that involve repeated push-and-pull stress.

Key to this mechanism is what the scientists call dynamic or sacrificial bonding -- multiple reversible and weak bonds on the sub-nanoscopic molecular level that can dissipate energy without compromising the overall adhesion and mechanical properties of the load-bearing material.

"Say you have one strong bond," Ahn explained. "It may be strong but once it breaks, it breaks. If you have several weaker bonds, you would have to break them one by one." Breaking each weak bond, he continued, would dissipate energy, so the overall energy required to break the material would be greater than with a single strong bond.

This type of bonding occurs in many biological systems, including animal bone and tooth. The mussel's byssus contain a high number of unique chemical functional groups called catechols, which are used to prime and promote adhesion to wet mineral surfaces. The new study shows that using a catecholic coupling agent instead of the conventional silane coupling agent provides 10 times higher adhesion and a 50 percent increase in toughness compared to current dental restorative resin composites.

While research has proven this toughening mechanism in soft materials, this study is one of the first -- if not the first -- to prove it with rigid and load-bearing materials.

This proof-of-concept, which also demonstrates no cytotoxicity, could mean tougher, more durable dental fillings. And that, in the long run, could mean fewer dental visits. Because each replacement filling also requires the dentist to file the surrounding tooth to prime its surface, given enough replacements a tooth might need to be crowned or extracted; and if not replaced, the tooth loss could have adverse consequences for the individual's diet and health.

The next step, Ahn said, is to increase the material's durability even further.

"By changing the molecular design you could have even denser coupling agents that exist on the surface, and then we can have a stronger and more durable dental composite," he said, estimating a commercial product within a couple of years.

Thursday, August 17, 2017

Oral and Dental Problems That May Signal Child Abuse and Neglect


A report from the American Academy of Pediatrics and the American Academy of Pediatric Dentistry in the August 2017 Pediatrics (published online July 31) aims to help identify problems involving a child's teeth, gums and mouth that may be signs of physical or sexual abuse and neglect. According to the updated clinical report, "Oral and Dental Aspects of Child Abuse and Neglect," injuries and infections in and around the mouth appear often in children who are maltreated. These may occur when caregivers react violently during developmentally normal fussiness at mealtime or bedtime, for example.

Symptoms that may be signs of child abuse or neglect include:
  • bruises on the lips, gums, tongue, lips or soft tissue inside the mouth from eating utensils or a bottle during forced feeding;
  • burns or blisters from scalding liquids or fractures to teeth, facial or jaw bones or scars or blackened teeth from previous injuries;
  • skin irritation, bruising or scarring at the corners of the mouth, which could be from gags applied to the mouth in forceful attempts to quiet a child;
  • injuries to the back of the throat, sometimes intentionally inflicted to make a child cough up or vomit blood or create other symptoms that would require medical attention and care;
  • injuries and infections tied to forced oral sex, such as tears and other signs of trauma inside the mouth or sores or rashes caused by sexually transmitted disease.
  • bite marks inside the mouth from the child's own teeth, which sometimes are caused by physical or sexual abuse.
In cases of dental neglect, authors note, untreated cavities and gum disease interfere with a child's ability to eat, communicate, grow and develop properly. The report also describes the connection between bullying and dental health, citing research indicating that children with mouth or dental abnormalities are frequent targets of bullying and face increased risk of depression and suicidal thoughts or actions.

In addition, the estimated 100,000 U.S. children involved in sex trafficking or forced prostitution each year have oral and dental problems from abuse and from malnutrition, which can lead to poorly formed teeth, cavities, infections and tooth loss.

Tuesday, August 15, 2017

Chewing gum rapid test for inflammation

Dental implants occasionally entail complications: Six to fifteen percent of patients develop an inflammatory response in the years after receiving a dental implant. This is caused by bacteria destroying the soft tissue and the bone around the implant in the worst case.
In future, patients will benefit from a quick and affordable method assessing whether they carry such bacteria: using a chewing gum based diagnostic test developed by a pharmaceutical research team at the Julius-Maximilians-Universit├Ąt (JMU) W├╝rzburg in Bavaria, Germany.

In practice, the test works as follows: If there is an inflammation in the oral cavity, a bittering agent is released while chewing the gum. Patients can then visit their dentist who confirms the diagnosis and treats the disease. This type of early detection aims at preventing serious complications such as bone loss.

"Anyone can use this new diagnostic tool anywhere and anytime without any technical equipment," Professor Lorenz Meinel says; he is the head of the JMU Chair for Drug Formulation and Delivery. He developed the new diagnostic tool with Dr. Jennifer Ritzer and her team; the invention is currently featured in an article in the journal Nature Communications.

Enzymes release bitter taste
The scientific background: In the presence of inflammatory conditions, specific protein-degrading enzymes are activated in the mouth. In just five minutes, these enzymes also break down a special ingredient of the chewing gum, thereby releasing a bittering agent that could not be tasted before.
Meinel's team provided the proof that this principle actually works. First studies using the saliva of patients were conducted at Merli Dental Clinic in Rimini.

Company establishment planned
To launch the chewing gum into the market, Meinel's team plans to set up a company. The professor assumes that it will take two to three years until the gum is commercially available.
Chewing gum rapid tests for other medical applications are presently under development. "We hope to be able to diagnose other diseases with our "anyone, anywhere, anytime" diagnostics to identify and adress these diseases as early as possible," Meinel explains.

Monday, August 14, 2017

High sugar consumption gives rise to dental treatment costs in the billions



Worldwide, people are eating far too much sugar. This has negative consequences for their teeth and for their purses: seen at the global level, the costs of dental treatment are currently running at around 172 billion US dollars (128 billion euros). In Germany alone, these amount to 17.2 billion euros (23 billion US dollars) a year. These are the results of a joint study conducted by the Martin Luther University Halle-Wittenberg (MLU) and the Biotechnology Research and Information Network AG (BRAIN AG) published in the International Journal of Dental Research. The work was carried out within the strategic alliance NatLifE 2020 and was co-financed by the German Federal Ministry of Education and Research (BMBF).

For their work the researchers evaluated representative data on the prevalence of caries, inflammation of the gums (parodontitis) and tooth loss, corresponding costs of treatment and the disease burden, as well as data on sugar consumption, in 168 countries for the year 2010. On the basis of this data they calculated the share of total costs attributable to excessive consumption of sugar. In addition to white household sugar, the researchers also focused their attention, in the analysis, to "hidden" sugar that is contained in many processed products, such as soft drinks, ketchup, ice cream and frozen foods, as well as breads, cakes and pastries.

"The data shows a clear correlation between the consumption of sugar and the incidence of caries, parodontitis and, as a result, tooth loss," said the lead author of the study, Dr Toni Meier from the Institute of Agricultural and Nutritional Sciences at the MLU. "For every additional 25 grams of sugar consumed per person and day - which amounts to roughly eight sugar-cubes or a glass of sweetened lemonade - the costs of dental treatment in high-income countries increase on average by 100 US dollars (75 euros) per person and year."

In Germany, the average daily sugar consumption lies between 90 and 110 grams per person. The costs of treatment amount to 281 US dollars (210 euros) per person and year. This puts Germany in the group of countries with the highest costs of treatment per person and year. Other countries "in the group" are Switzerland (402 US dollars, 300 euros), Denmark (238 US dollars, 178 euros) and the USA (185 US dollars, 138 euros). "If the target of 50 grams of sugar per person and day set by the World Health Organization could be reached, this would result in savings in the costs of treatment within Germany of 150 euros (201 US dollars) per person and year. Extrapolating this figure to the federal level shows annual potential savings of approximately 12 billion euros, or 16 billion US dollars," added Meier. A low-sugar diet is becoming increasingly difficult, however, since almost all processed products in the supermarket contain large quantities of added sugars.

The highest levels of sugar-related dental illness were observed by the researchers in Guatemala, Mauretania and Mexico. "Newly industrialised countries such as India, Brazil and Mexico, but also Pakistan and Egypt, could avoid an excessive burden of illness and of health care costs by anchoring the topic in their health and nutritional policies at an early stage," said the co-author of the study and nutrition scientist, Professor Gabriele Stangl of the MLU. This objective could be achieved by way of educational campaigns or by special taxation on high-calorie food. Such a sugar tax was introduced in Mexico in 2014 and already after one year was proving to be effective: the consumption of sugar-sweetened beverages had decreased by five percent. In the second year this decrease even doubled to ten percent.

"To be able to reduce the burden of nutrition-related illnesses, a balanced mix of educational work and food-policy initiatives, along with innovative technological solutions, are needed," said the co-author of the study, Dr Katja Riedel, joint coordinator of the NatLifE 2020 innovative alliance and program manager of system-products nutrition at BRAIN AG. The alliance co-financed by the German Federal Ministry of Education and Research aims, with the help of biotechnology and the understanding of biological systems, to develop a new generation of sustainably produced and biological active substances for foods and cosmetics and thereby to make a contribution towards improving human nutrition, health and well-being.