Better Chewing Ability Might Reduce Dementia Risk

Now it seems that Swedish researchers have a found a new factor that influences the risk of suffering from dementia: Chewing ability.

smiling-senior-coupleDementia – the deterioration of our cognitive functions and gradual loss of abilities such as memory, decision-making and problem solving – is a condition that doctors and scientists have long been searching for a way to cure or prevent. Now it seems that Swedish researchers have a found a new factor that influences the risk of suffering from dementia: Chewing ability.

A team researchers at Karolinska Institutet and from Karlstad University in Sweden looked at tooth loss, chewing ability and cognitive function in a group of 557 people aged 77 or older. Comparing all the data, they found that among those who had difficulty chewing hard food such as apples there was a much higher risk of developing dementia. The connection between chewing ability and dementia risk was not related to variables such as sex, age, education and mental health problems which have also been reported to influence the dementia risk. Whether the chewing ability was maintained with dentures or with natural did not effect the dementia risk either. As long as the person was able to chew well, the dementia risk was lower.

There is still no clear answer as to why chewing ability has an impact on the dementia risk. One theory is that a lower chewing ability means less blood flow to the brain. The question of the exact connection must be further researched.

Our chewing ability is linked to the number and quality of our teeth. A loss of chewing ability could be the cause of numerous cavities or periodontitis, which can all be prevented through adequate dental hygiene.

Duangjai Lexomboon, Mats Trulsson, Inger Wårdh & Marti G. Parker: Chewing Ability and Tooth Loss: Association with Cognitive Impairment in an Elderly Population Study
Journal of the American Geriatrics Society, 4 October 2012
Karolinska Institutet

Nanocrystals could be used to make natural looking dentures

Scientists have managed to produce a new kind of glass ceramic with a nanocrystalline structure, which seems to be well suited for use in dentures and bridges

denture-and-dental-formDentures need to be able to stand the same pressure as natural teeth. At the same time they must be made of a material that makes them look natural. Many dentures might feel right but don’t look natural or the other way around. Now, however, a group of scientists have managed to produce a new kind of glass ceramic with a nanocrystalline structure, which seems to be well suited for use in dentures and bridges due to their high strength and natural shine.

The new glass-ceramics are made on the basis of magnesium-, aluminium-, and silicon oxide and are distinguished by their enormous strength. “We achieve a strength five times higher than with comparable denture ceramics available today”, Prof. Rüssel explains. So far the high density ceramics,have only been used in other fields such as in computer hard drives.

Materials used in dentures are not supposed to look different from natural teeth. It is also important that the colour shade is right, and since the enamel of natural teeth is partly translucent, so should the enamel of the dentures be.

The making of nanocrystals

To achieve this goal, the basic materials of the glass-ceramics are first melted at about 1.500 °C, then cooled down and finely cut up. They are then melted again and cooled down again. Finally, nanocrystals are generated at a controlled heating to 1,000 °C. This way the crystallisation which is so important for the strength of denture material is secured. For the crystals to look naturally translucent, the size of them should not be more than 100 nanometers. This way, they are too small to strongly disperse light and will not look opaque like some other denture materials. The enamel will look translucent and dentures made from this material will be strong and at the same time look natural.

The science of making these nanocrystals will need to be further developed before they can be used in dentures, but researchers feel sure that their technology might be the future of natural looking dentures.

Dittmer M, Rüssel C.: Colorless and high strength MgO/Al2O3/SiO2 glass-ceramic dental material using zirconia as nucleating agent. J Biomed Mater Res B Appl Biomater. 2011 Nov 21. doi: 10.1002/jbm.b.31972

Premature babies grow smaller teeth

Research conducted at Malmö baby-black-in-white-dressUniversity’s Dental Faculty has proved that children born before the 33rd week of pregnancy will grow permanent teeth that are up to 10% smaller in size compared with other children. The research was conducted by orthodontist Liselotte Paulsson-Björnsson, who examined the permanent front teeth and 1st molars in 80 children aged 8 to 10 years. All children had been born prematurely and their teeth were generally smaller and had larger spaces between them. Although this does not affect the function of the teeth it might cause problems cosmetically, thus creating a greater need for orthodontic treatment in this group of children.

Liselotte Paulsson-Björnsson points out that due to the great progress in the care of prematurely born babies within the last 15 years, the results of her research might not apply to babies born prematurely today. She also needs to examine whether it is only the front teeth and 1st molars that are affected or whether teeth developed after birth will also be smaller.


Can periodontal disease cause premature birth?

Several studies show that there is a link between periodontal disease in pregnant women and premature birth. What is the link and how can you protect yourself?

good oral health in pregnancySeveral epidemiological studies seem to support the theory that there is a link between periodontal disease in pregnant women and premature birth. For instance, one study suggested that pregnant women with periodontal disease are as much as seven times more likely to have babies that are born too early or have a relatively low birth weight.

Why does periodontal disease cause premature birth?

Although the connection between periodontal disease and premature birth seems clearly to be existing, researcher are still not certain about the reasons for this connection.

One theory is that periodontal disease triggers increased levels of the biological fluids that induce labor. In other words, the regulators that are supposed to send the message that birth is to begin are produced elsewhere in the body and the message is sent prematurely. Some of these regulators are called prostaglandins, and they can be produced by different diseases, among which is gum disease.

Another theory is that oral bacteria from the mother is transferred directly into the uterus, causing localized inflammation and adverse pregnancy outcome.

Maintain good oral health during pregnancy

Whatever the reason for the connection between gum disease and preterm birth, it is clear that it is crucial for pregnant mothers to maintain good oral hygiene through the whole pregnancy. Discomfort in connection with the pregnancy such as nausea may at times make it difficult to keep up the good oral hygiene habits from before the pregnancy, but with determination and good support from your dental health professional is it not impossible.

One advice that many pregnant mothers have benefitted from is to buy a toothbrush with soft bristles and a small head. If you suffer from nausea, a smaller toothbrush will make it easier to reach the teeth in the back of your mouth without causing too much discomfort. The soft bristles will also be more gentle on your gums, which might be extra sore during your pregnancy.

Some pregnant mothers experience more serious dental health problems during pregnancy, such as bleeding gums, loose teeth and bad breath despite frequent brushing. If you experience such problems, you might benefit from a visit to your dentist or dental hygienist. They can help evaluate the condition of your gums, make you aware of areas that you need to pay more attention to and teach you how to care for your own oral health and thereby the health of your baby.

Does oral bacteria cause multiple sclerosis?

Research points to an oral bacteria as a contributing factor to the development of multiple sclerosis. Results can affect the treatment of multiple sclerosis and provide new markers for disease activity.

dnaMultiple sclerosis (MS) is a disease where the immune system attacks the brain and spinal cord. The disease causes a wide range of neurological symptoms that include muscle weakness, difficulty in moving, difficulty in speech and many other impairing and painful conditions.

While doctors are very clear about the symptoms and processes of autoimmune diseases such as multiple sclerosis, they have long been in the dark as to the “tipping” factors, that is the factors that make the body’s immune system start to attack its own tissues. However, some research points to an oral bacteria as a contributing factor to the development of multiple sclerosis. The oral bacteria in question is called Porphyromas gingivalis and is common in humans. It produces a unique type of lipid, which enhances inflammatory responses.

Researchers at the University of Connecticut Health Center have tried to determine whether these lipids play a role in exacerbating autoimmune disease. Results indicated that phosphorylated DHCs from bacteria commonly found in humans may actually trigger or increase the severity of multiple sclerosis and other autoimmune diseases.

Although results like these are indeed good news for those suffering from multiple sclerosis and those at risk of developing the disease, more research is still needed before the research can be used in therapeutic treatment and prevention of multiple sclerosis. For instance, scientists still need to characterize the effects of the oral bacteria on specific cells of the immune system and to identify how and where these lipids are deposited in the body’s different tissues. In addition to triggering and worsening multiple sclerosis, scientists believe that the oral bacteria may have the potential to serve as new markers of multiple sclerosis disease activity and as targets for therapeutic intervention.

Can nanotechnology replace dental fillings?

Last week many media outlets reported that nanotechnology made a gel that can regenerate teeth and make dental fillings obsolete. Is this true?

Root canal instrumentsA group of French scientists within the field of nanotechnology recently made big headlines all over the world, when they published a study about a nanotechnology gel that could regenerate teeth. The research was by several media outlets interpreted to mean that dental fillings would soon be made obsolete by this new breakthrough in nanotechnology. It was reported that the gel could just be added to the cavity of the tooth and that the tooth would then repair itself without ever needing a filling. Is this true? Is nanotechnology really this close to replacing dental fillings as the primary treatment of tooth cavities?

The fact of the matter in this case is that nanotechnology is not about to replace dental fillings. The research was about how to regenerate the pulp inside the tooth and not the crown itself. The pulp of the tooth consists of nerves and blood vessels. It is a live tissue in contrast to the tooth enamel which consists of approximately 96% inorganic material. Sometimes the dental pulp becomes infected due to deep cavities or trauma. When the dental pulp becomes infected it will start to die and so far the only treatment of this condition has been to remove the dental pulp and replace it with a soft material called gutta-percha. After such a root canal treatment the tooth will be dead and is now weaker than before. It will often be necessary to protect the now more fragile tooth with a dental crown to prevent it from breaking or cracking.

What the French nanotechnology researchers might have discovered is a way to regenerate the dying pulp so that the tooth won’t have to die. By using a multilayered, nano-sized film — only 1/50,000th the thickness of a human hair containing a substance called alpha melanocyte stimulating hormone, or alpha-MSH the nanotechnology scientists have proved that they can fight inflammation and increase the number of dental pulp fibroblasts. Fibroblasts are the cells inside the dental pulp that regenerate the pulp fibres and are the main type of cell found in dental pulp.

Hopefully this new breakthrough within nanotechonology – which has so far only been tested on laboratory rats – will in time reduce the need for root canal therapy.

Most people have mercury in their blood – is it harmful?

A new report from the CDC shows that most people have measurable levels of mercury in their blood and urine. What are the dangers?

chemistryA new report from the US Centers for Disease Control and Prevention (CDC), reveals that scientists have found measurable levels of mercury in most of the 8500 persons who recently took part in a national health and nutrition survey. In the comprehensive research program scientists analyzed blood and urine samples in order to measure the total mercury content of the large number of participants.

The report from the CDC concluded that:

* Most of the participants had a measurable amount of mercury in their bodies.

* Mercury levels tended to increase with age.

* All blood mercury levels were less than 33 µg/L.

* Blood and urine mercury in the US population were similar to levels seen in other developed countries.

Although the mercury levels caused by dental fillings are not thought to be harmful to the human body, the CDC scientists admitted that determining what constitutes “safe” levels is still a question that needs to be researched more.

Determining safe levels of mercury exposure is of utmost importance since even small amounts of blood mercury content is suspected of causing neurodevelopmental effects in children. These effects include mental retardation, ADHD, autism and other neurological disorders.

The toxicity of mercury

There are different kinds of mercury, which are not all thought to be equally harmful to humans. Elemental mercury is found in many of the goods that we are exposed to every day such as thermometers, some light bulbs and dental amalgams. Elemental mercury is also used in industry and mining where it gets into the air when coal and other fossil fuels are burned. When we breathe in air that contains mercury vapour, elemental mercury enters our bodies.

In the body, elemental mercury usually forms inorganic compounds. Elemental mercury has not been proven harmful in small doses. However, very high levels of vapour concentrations can lead to severe lung damage, and exposure to low vapour concentrations over a long period of time can cause neurological disturbances, memory problems, skin rash, and kidney abnormalities.

Methyl mercury – the real cause for concern

The kind of mercury which causes the most concern is the kind which is called methyl mercury. Methyl mercury is formed, when microorganism in the marine environment “eat” and metabolize elemental mercury. These microorganisms and their methyl mercury content are then eaten by larger fish and other organisms and the methyl mercury is thus accumulated as it travels up through the food chain. At the top of the food chain we, the humans, are exposed to the methyl mercury when we eat fish or shellfish. Methyl mercury is especially harmful for pregnant women, because of its ability to pass through the placenta into the developing fetus where it might cause neurological damage.

Mercury from dental fillings is thus not as harmful to humans while it is in the mouth (elemental mercury) as it becomes when it ends up in the environment and is transformed into methyl mercury. As neurological defects in children continue to be on the increase however, scientists continue to study the toxicity of chemicals such as mercury and to question the existing “safe” levels of exposure to these.

“National Report on Human Exposure to Environmental Chemicals.”
CDC, National Center for Environmental Health, 2009.
US Department of Health and Human Services.

Scientists make first bio-engineered tooth ever!

Imagine if your dentist were able to make a new tooth grow out of your jaw! This sci-fi vision might soon be within reach…

tooth-painImagine that, instead of replacing lost teeth with bridges and implants, your dentist would be able to make a new tooth grow out of your jaw! It sounds like science fiction, but the vision might not be out of reach.

A group of Japanese scientists have recently succeeded in making the first fully functional, bio-engineered organ ever – and it’s a tooth! The key to making these ‘real’ teeth is the use of stem cells. Stem cells are special because they have the potential to develop into different tissue and organs.

It has long been the dream of scientists to make stem cells grow into organs that can be transplanted into patients in need. Previously, researchers have succeeded in making different tissues out of just one kind of stem cell. In order to make fully functioning, three dimensional organs, more than one kind of stem cell would need to be combined.

In making the bio-engineered tooth, scientists figured out how to combine two different kinds of stem cells – stem cells developing into inner and outer surfaces and stem cells developing into blood vessels and other soft tissues. The two kinds of stem cells combined into a tooth germ which was then transplanted into the jaw of mice in place of recently extracted teeth.

Already after a couple of weeks, the new tooth erupted through the gum and after 49 days, it was fully erupted. The tooth was tested as to hardness and function and was found to be fully functional and up to the standard of natural teeth.

What this new discovery will mean for the dental profession and for regenerative therapy in general is still unclear and many questions need to be answered before the technology can be used on humans. So it might still be long before you can order your own bio-engineered tooth at the dentist.

Is obesity caused by oral bacteria?

Is obesity an infectious disease? British scientists have found that the presence of a certain oral bacteria is higher in women suffering from obesity.

Can oral bacteria cause obesity?A group of British scientists have asked – and possibly answered – this question through a study of 500 women. Around 60% of the women in the study suffered from clinical obesity. When examining saliva samples from the obese women and comparing them with samples from a control group of average weight women, scientists found that the presence of a certain species of oral bacteria – selenomonas noxia – was significantly higher in 98% of the overweight women.

The exact connection between the oral bacteria and obesity is still unclear. “It is uncertain whether people may become obese due to changes in the bacteria in their mouths or whether these changes occur as a result of obesity,” said Dr Nigel Carter, chief executive of the British Dental Health Foundation. “What impact changing the bacterial make up may have on helping to reduce obesity is certainly worth additional research.”

The oral bacteria, Selenomonas noxia, has previously been connected with gum disease and poor dental health. Scientists think it likely that this oral bacteria could serve as a biological indicator of a developing overweight condition. As possible connections between oral bacteria and obesity, it has also been speculated whether certain bacteria may have the ability to increase the appetite of individuals and make the body store up nourishment from food, causing a weight increase.

There has previously been found connections between oral health and other conditions such as diabetes and cardiovascular disease. Obesity has also been identified as a risk factor in the development of oral disease.

There is a clear connection between obesity and oral health in the fact that food products with a high sugar content have the potential to cause both obesity and dental cavities. Whether there are further connections between the two conditions will be researched further.

Scientific research: Tooth extraction for preventing displaced canines in children?

Is tooth extraction effective in preventing adult canines from erupting in the wrong place? A new study by Cochrane researchers brings new information about the scientific basis for tooth extraction of baby canines.

Braces on teenagerIs tooth extraction effective in preventing adult canines from erupting in the wrong place? A new study by Cochrane researchers brings new information about the practice of tooth extraction of baby canines.

Why consider tooth extraction?

The adult canine teeth (tooth number 3 from the middle) erupt around the age of 12. In 2-3% of all 12-year-olds the canine tooth erupts in the wrong place – in the roof of the mouth. It has been of great concern to dentists to prevent the canines from erupting in the wrong place, since this can cause damage to the neighbouring teeth or cause unfavourable movement of these teeth. For many years extraction of the baby canines been the practice of dentists in order to make way for the adult canine teeth. But does tooth extraction prevent displaced canines?

Is tooth extraction effective?

According to the Cochrane review there is no substantial scientific evidence that extraction of the baby canine teeth will prevent displaced eruption of the adult canine tooth. “The recommendation of extracting the baby canine is in fact based on one uncontrolled study that was carried out over twenty years ago,” says one of the authors of the study. The study seemed to prove that tooth extraction makes way for the adult canines, but since there was no control group in the study, the evidence is not conclusive.

Is tooth extraction ineffective, then?

The absence of evidence, however, does not necessarily mean that tooth extraction is not an effective method. The study concludes that there is a need to improve the quality of the research on the question of whether or not tooth extraction can be recommended in order to help the canine teeth erupt correctly.

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