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.

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

Constipation and bad breath - the reasons

Constipation causes an accumulation of undigested food in the bowels and the problem is thought to be caused by a passive lifestyle with a lack of exercise. Many people who suffer from constipation have a job that requires them to sit all day, which does not do much good for the digestion. When combined with a diet low in fibres and a general lack of exercise, constipation is very likely to result which again causes the bad breath.

Constipation and bad breath - the solution

If people are to solve their problems with constipation and bad breath, they need to improve the function of their bowels. In order to solve the problem with constipation, doctors recommend regular exercise, a diet rich in fibres and low in fat and a habit of drinking water every hour.

When dentists are faced with patients who suffer from bad breath without having any problems with oral hygiene or oral health, they are recommended to ask the patient whether he or she has been experiencing problems with digestion or stomach aches, has felt bloated or in any other way uncomfortable or tired. If the answer is yes, the patient might be advised to see a doctor who specializes in intestinal problems.

Most medicines have an effect not only on the area of your body that they are supposed to treat, but on your whole organism. Many side effects of medicine can be seen in the mouth e.g. as dryness or increased bleeding. An example of medicine that it is especially important for you to inform your dentist about is anticoagulants (or blood thinners). Blood thinners are administered to prevent blood clots, but this medicine can cause problems during dental treatment, because it makes your gums bleed more after for example extractions or dental cleanings.

Some dentists will recommend their patients to stop taking the anticoagulant medicine just before dental treatment in order to prevent bleeding, but newer research has shown that the risk of stopping the medicine intake temporarily is too high compared with the danger of the bleeding caused by the medicine.

Instead of advising the patients to halt their medicine intake temporarily, the dentist might therefore take extra precautions during and after treatment to make sure that the bleeding has stopped before the patient leaves the clinic. When choosing what kind of pain killers to recommend to the patient, the dentist should also be aware that some pain killers enhance the effect of the blood thinning medicine.

If you are in doubt about whether your medicine is important for your dental treatment, talk to your dentist about it next time you see him. In fact. make it a habit always to tell your dentist when you have started taking new medicine or if your dosage has been changed.

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.

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.

Is it contagious?

It is probably no surprise to anyone that the flu is contagious. But what is the risk of spreading or contracting a flu in the dentist’s chair? In most countries there are laws requiring dentists to adhere to certain hygiene standards. According to these standards, dentists must desinfect the clinic and sterilize all instruments between each patient. Dentists will also in most cases choose to wear gloves, surgical masks and ‘glasses’ in order to protect both themselves and the patients. If these hygienic standards are followed, the risk of spreading viral and infectious diseases at the dental clinic is minimized. As a further precaution, the dentist can avoid using water spray and make sure to open the windows between patients.

In some cases – e.g. epidemics such as the swine flu – doctors might advise all patients to stay at home while suffering from the flu in order to avoid spreading the disease. This advice should be respected and the dentist will be understanding if you make sure to cancel your appointment as early as possible.

Can it be done?

Will it be possible for the dentist to examine you and/or treat you in your present condition? If you are having a cold or a flu, you might be suffering from a stuffy nose. During dental treatment you might not be able to breathe through your mouth. Consider, therefore, whether your condition will make it too difficult for the dentist to perform the needed treatment.

If you are still in doubt whether or not to visit the dentist with a flu, you can choose to call your dental office, explain your symptoms and ask their advice.

If you experience any kind of pain from your teeth, you should always consult your dentist to make sure that the pain is not caused by more serious problems such as cavities or periodontal disease. If your dentist has already ruled out these causes, you will probably be diagnosed with sensitive teeth. Teeth become sensitive when the nerve inside the tooth is stimulated. The nerve of the tooth does not distinguish between hot, cold or any other stimulus. In whatever way the nerve of your tooth is affected, it will feel the same: painful. Normally your tooth enamel offers the necessary protection and your teeth shouldn’t be sensitive to cold, warm, sweet or sour. When for some reason a part of your tooth is not protected by enamel, the result is sensitive teeth. There can be several reasons, why a person develops sensitive teeth:

Exposed tooth roots

Normally the crown of your tooth is protected by enamel and the root surfaces are protected by the gums. But sometimes the gum line recedes, leaving your root surface exposed and sensitive. This can happen if your brushing technique has been incorrect for a while:

• Do you use a hard toothbrush?
• Are you a little rough, when you brush?
• Do you use circular movements or back-and-forward movements with your toothbrush, when you brush?

The correct technique for brushing your teeth is to use a medium soft toothbrush and not press it too hard against the gums. If the brushes on your toothbrush are bending outwards rather than standing straight, this is a sign that you need to be less rough. If your gums turn white while you brush on the edge between the teeth and the gums, this is another sign that you are using too much pressure. The correct brushing technique also involves small circular movements rather than straight movements back and forward across the teeth. Your dentist or dental hygienist can instruct you on the proper brushing technique.

Another common reason for exposed tooth roots is periodontal disease, which causes the bone and the gum to recede. Gums that have receded cannot return to their place, so it is important to prevent them from receding in the first place.

Worn teeth

Teeth that are worn can be very sensitive as well. Some people grind or clench their teeth, when they are stressed or while they sleep. Teeth grinding wears down the teeth and makes them sensitive. The first layer to be worn off is the enamel. When the enamel is gone, the next layer (called dentine) is exposed. Dentine is not as hard as the enamel and does not offer the same protection. This might cause your teeth to become sensitive.

Cracked teeth

If your teeth are sensitive, but there are no exposed root surfaces or signs of wear, the reason might be a crack in the tooth. Most people have small cracks in their teeth and never feel pain from them. For others, even a tiny crack can make a tooth extremely sensitive.

What can be done?

Proper oral hygiene is a must in order to treat your sensitive teeth. Learn how to brush properly and thoroughly without causing damage to your teeth and gums. Even if your gums have already receded, keeping the root surfaces plaque free is an important step toward making them pain free. If the root surfaces are covered in plaque, they will be more sensitive, since the plaque produces acid which etches away on the root surface. If, on the other hand, the root surface is clean, the surface will be able to create a protective layer and will be less sensitive.

Use the right toothpaste

Toothpaste containing fluoride helps protect your teeth. The fluoride combines with the calcium in your saliva to ‘harden’ the surface of your teeth. Some people even find it very helpful to leave a layer of toothpaste on the sensitive spots on their teeth after they have brushed.

It is also possible to buy desensitizing toothpastes, which help block transmission of sensation from the tooth surface to the nerve.

What the dentist can do

If the more simple measures mentioned above do not work, your dentist might be able to help you in other ways. A fluoride gel can be applied in the clinic or a hard sealer (usually made of a plastic material) can be applied over the sensitive part of your tooth in order to protect it mechanically. If you have a very sensitive root surface, which has also become concave from brushing, a filling can be laid which will offer protection and make the tooth less sensitive.

It is worth noting, however, that if your brushing technique continues to be incorrect, neither varnishes nor fillings will last very long before you have brushed them away and your teeth are sensitive again.

If the reason for your sensitive teeth is wear from grinding or clenching your teeth, you might need to think about why you have this habit. If the reason is stress, consider doing something about the stress. If it is just a bad habit and it is not possible to stop, you can have your dentist make a mouth guard. A mouth guard will not take away your habit, but it will at least protect your teeth from being worn and increasingly sensitive from it.

Other more radical measures against sensitive teeth is capping of the tooth or even root canal therapy, which takes out the nerve of the tooth and puts and end to the pain altogether.

Why lower dentures don’t stay put

One of the great challenges when making a denture is to make it ‘stay put’. Especially a full denture in the lower jaw often has problems with retention. There are several reasons for this:

1) A denture has the best retention, if it fits around the jaw bone. The bone in the lower jaw is often too flat for this and the denture might slide around or tip on top of the gum.

2) The upper full denture has the advantage of a sort of ‘suction’ between the denture and the palate, because the denture covers the whole palate. In contrast, the denture in the lower jaw can only be U-shaped because of the tongue. As a result, the contact area between the denture and the gum is relatively small and there can be no suction between the denture and the gum.

Many people have no problems with their full lower denture, but for others the inadequate retention of the denture causes problems when speaking and chewing food. For these a ‘snap-in’ denture might be a good solution.

Snap-in dentures

The ideal conditions for a snap-in denture is, if the roots of a couple of your natural teeth (preferably the canine teeth) are still left in the jaw to attach the denture onto. But even if you have none of your natural teeth left, it is still possible for you to have a snap-in denture made by implanting titanium roots into the jaw.

Snap-in dentures and implants

The procedure of making an implant is not as complicated as it sounds. First, a little hole is drilled in the bone and a titanium screw is placed in the hole. After a few months the bone has healed so well around the screw that it is completely attached to the bone and it is stable enough to support a denture.

The snap-in concept

Whether you have natural roots of implant roots, the snap-in system works the same way: A little ball-shaped attachment is added on top of the root. On the denture is attached a little lock that fits perfectly together with the attachment on the root. When the denture is placed over the root, the attachments snap in place and the denture will stay put.

How many ’snaps’?

Normally a minium of two original roots or implant roots are required to achieve a good result with a lower denture. For the upper denture more than two roots are needed for retention.

What are teeth implants?

Teeth implants are artificial roots of metal that are implanted in your jaw bone to replace missing teeth. On top of the implanted metal root it is possible to attach a crown, a bridge or a set of dentures depending on how many teeth need to be replaced. If cared for properly teeth implants can function and look exactly like natural teeth and can last much longer than most of their alternatives.

What are teeth implants made of?

The roots of teeth implants are made of titanium. Titanium is a very suitable metal for implants, because it is able to interact with the natural bone tissue in such a way that the implants become integrated into the jaw bone. This proces is called osseointegration and is a unique quality in titanium the discovery of which made implants possible. The roots of the implants are normally shaped like a screw which makes the integration very strong. Crowns attached on top of teeth implants are normally made of porcelain to make the implants look as natural as possible.

Why choose teeth implants?

Dental bridges and dentures are good alternatives to implants and will in many cases be the preferred choice. In other cases there is a wish to replace the missing teeth with something that functions and looks more like the natural teeth. This might be the case with young people who lost a tooth because of caries or trauma, and where the bone structure and surrounding teeth are healthy and sound. In these situations teeth implants are a good alternative.

Sometimes teeth implants are also used to add retention to dentures or to attach bridges onto, when there are no natural teeth that can serve as anchors. When implants are used as anchors for dentures, ’snap-in’ buttons’ are attached on top of the implants instead of porcelain crowns. More about dentures and dental bridges here.

Bad breath

Why do I have bad breath?

Many people are convinced that their bad breath comes from their stomach, but recent research has proved that most cases of bad breath are caused by germs on the surface of the tongue. In fact, it is estimated that germs on the tongue account for as much as 90% of all cases of bad breath. Simply put, the germs release gases that cause the bad smell. If you examine your own tongue in the mirror you will discover that it’s surface is actually very rough. Especially the area near the root of your tongue is a perfect breeding ground for the germs that cause bad breath.

Another connection between germs and bad breath is that germs can build up as plaque and eventually cause gum disease (periodontitis) and cavities. Plaque in itself can cause bad breath, but especially periodontitis and cavities can cause a very bad smell from the mouth because of the kind of germs that live in cavities and deep periodontal pockets.

Tonsil stones (or tonsilloliths) are yet another reason why some people suffer from bad breath. Tonsil stones are whitish/yellow little lumps that sometimes accumulate in the small pits on the surface of your tonsils. The lumps consist of sulfur-producing bacteria and debris from your mouth and nose and they can both taste and smell bad.

What can be done about bad breath?

If your bad breath is caused by plaque, you will need to work harder on your dental hygiene. Maybe you already brush your teeth at least twice a day or even more often – but are you thorough enough? Do you make sure to brush every surface of all your teeth (even the difficult-to-reach ones in the back of your mouth) or do you tend to brush the same few teeth every time?

If your bad breath is caused by cavities or periodontitis you will need to see your dentist for treatment. These problems cannot be solved by improving your oral hygiene alone. Your dentist or dental hygienist will probably also advise you on how to maintain a high standard of oral hygiene and how to avoid bad breath in the future. You can talk openly to your dentist or dental hygienist about your bad breath. It is their profession to deal with these things and there are no taboos in the dental clinic.

If your teeth are already healthy and your dental hygiene is good but you still suffer from bad breath, you might need to start cleaning your tongue as well. Your tongue can be cleaned by brushing it with your toothbrush. If brushing your tongue with your toothbrush makes you gag, you could try to use a tongue scraper which is especially designed for cleaning the tongue and treating bad breath.

If you see little white lumps or tonsil stones on your tonsils and you think they are the cause of your bad breath, you might be able to squeeze them out by pressing a finger or a Q-tip against the bottom of the tonsil and pushing upward. If your gag reflex prevents you from sticking fingers or Q-tips in your throat, the tonsil stones might be removed if you simply flex your throat and swallow. If you are not successful at any of these methods, your dentist can help you.

Hopefully the advice in this article can help you do something about your bad breath. Do not accept bad breath as part of your life. It might be a sign that something is wrong or – to look on the bright side – it might be a surprisingly easy problem to solve!