Thursday, December 25, 2008

Children With Autism Have Fewer Cavities

Young people with autism and related disorders are less likely than other children to get cavities, a study has found. But more of these children don't cooperate at the dentist's office.

Dentists from Tufts University, Boston University, and Calgary, Alberta, did the study. They enrolled 781 children and young adults. All of them made regular visits to the dental department of Franciscan Hospital for Children in Boston.

Of the young people in the study, 395 had an autism spectrum disorder. ASD is a group of disorders of the brain. People with ASD have problems with communicating and social interaction. ASD includes autism, Asperger's syndrome, and pervasive developmental disorder not otherwise specified, or PDD-NOS.

Of the young people with ASD, 78.5% had autism, 19.5% had PDD-NOS, and 2% had Asperger's syndrome. All three groups had about the same rate of cavities.

About 82% of the ASD patients were boys. ASD patients tended to be older than other patients. Their median age was 12, compared with 8 for people without ASD. The authors note that many ASD children are encouraged to keep coming to the children's hospital as adults because they have become comfortable there. Routine can make visits easier.

ASD patients under age 6 were 83% less likely to have had cavities than other children of the same age. Those ages 6 to 17 were about 66% less likely to have had cavities.

The researchers also rated behavior during the dental visit. In the ASD group, 55% of children were uncooperative, compared with 25% of the other children. About 9% of the ASD children and 47% of other children were very cooperative.

About 38% of children with ASD needed general anesthesia to have dental treatment done, compared with 30% of the other children.

Of the young people with ASD, 78.5% had autism, 19.5% had PDD-NOS, and 2% had Asperger's syndrome. All three groups had about the same rate of cavities.

Several other factors also did not make any difference in cavity rates for people with ASD. They included:

  • Taking medicine for ASD
  • Being in an institution
  • Having a seizure disorder
  • Having another condition, such as cerebral palsy

Other studies have found that children with autism have either fewer cavities than other children or about the same number.

Other researchers have suggested that children with ASD have less decay because they are less likely to favor sweet foods and snack between meals. Some have suggested that good home care by a parent or caregiver helps prevent decay.

Many children with autism are extremely selective about what they eat. They may like foods with only a certain texture, or only salty foods, for example. A 2007 study of 87 autistic children found that their favorite foods included chicken nuggets, French fries, bananas, candy and green beans.

November 12, 2008

by Nancy Volkers
InteliHealth News Service

Gene Therapy May One Day Fight Periodontal Disease

Researchers have tested gene therapy for treatment of periodontal disease in rats. The therapy appears to help fight the disease. Periodontal disease is a bacterial infection. When the body tries to fight the infection, it releases molecules that can damage gums and bone.

Gene therapy uses a virus that has been altered to keep it from causing disease. The virus is used to add a gene to certain cells in the body. In this study, researchers from the University of Michigan added a gene to rats. The gene makes a protein that removes some of the molecules that are damaging the gums and bone.

In this experiment, rats had the bacteria that cause periodontal disease placed in their mouths. Then, gene therapy was given. The therapy stopped most of the gum and bone damage around the teeth. It also reduced the amount of inflammation-causing proteins.

Rats given the gene therapy also had fewer osteoclasts. These are cells that break down and remove bone.

The researchers are working with a biotech company called Targeted Genetics. This past summer, the company released a study showing that this type of gene therapy could be used to help people with rheumatoid arthritis. That study involved more than 120 people. The gene therapy reduced pain and helped people function better.

This is the first known research to use gene therapy for the treatment of periodontal disease. Researchers are planning next to test it on humans.

December 17, 2008

by Nancy Volkers
InteliHealth News Service

All About Cavities

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space placeholder.What's in Your Mouth?
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To understand what happens when your teeth decay, it's helpful to know what's in your mouth naturally. Here are a few of the elements:

  • Saliva — Your mouth and teeth are constantly bathed in saliva. Although we never give much thought to our spit, this simple fluid is remarkable for what it does to help protect our oral health. Saliva keeps teeth and other oral tissues moist and lubricated, washes away some of the food particles left behind after we eat, keeps acid levels in the mouth low, and protects against some viruses and bacteria.

  • Plaque — Plaque appears as a soft, gooey substance that sticks to the teeth a bit like jam sticks to a spoon. It is, in fact, colonies of bacteria, protozoa, mycoplasmas, yeasts and viruses clumping together in a gel-like organic material. Also in the mix are bacteria byproducts, white blood cells, food debris and body tissue. Plaque grows when bacteria attach to the tooth and begin multiplying. Plaque starts forming immediately after a tooth is cleaned; it takes about an hour for plaque to build up to measurable levels. As time goes on, different types of microorganisms appear, and the plaque thickens.

  • Calculus — If left alone long enough, plaque begins to mineralize and harden into calculus or tartar because the plaque absorbs calcium, phosphorus and other minerals from saliva. These minerals form crystals and harden the plaque structure. New plaque forms on top of existing calculus, and this new layer can also become calcified.

  • Bacteria — We have many different strains of bacteria in our mouths. Some bacteria are good; they help control destructive bacteria. When it comes to decay, Streptococcus mutans is the bacterial strain that does the most damage. It attaches easily to teeth and produces acid.
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space placeholder.How Your Teeth Decay
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You need food, particularly sweet and sticky food, for the bacteria in your mouth to produce acids that will attack the tooth enamel (outer surface of the tooth). Sugars, especially sucrose, react with bacteria to produce acid. The acid from the bacteria can decay your teeth.

It's not just candy and ice cream we're talking about. All carbohydrate foods, as they are digested, eventually break down into simple sugars, such as glucose and fructose. Some of this digestion begins in the mouth. Foods that break down into simple sugars in the mouth are called fermentable carbohydrates. These include the obvious sugary foods, such as cookies, cakes, soft drinks and candy, but also pretzels, crackers, bananas, potato chips and breakfast cereals. The sugars in these foods combine with the bacteria normally in the mouth to form acids. These acids cause the mineral crystals inside the teeth to begin to dissolve.

The dental caries lesion forms when these acids start to dissolve a tooth's outer protective layer, the enamel. A cavity forms when the tooth decay breaks through the enamel to the underlying layers of the tooth. You can reverse a caries lesion (before it becomes a cavity) by using a variety of fluoride products. These include fluoridated water, fluoride rinses for use at home, and, of course, any commonly used fluoridated toothpaste.

Every time you eat, the bacteria in your mouth produce acid. Therefore, the more times you eat the more times your teeth are exposed to an acid attack.

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space placeholder.Types and Stages of Decay
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Dental decay, also known as dental caries, begins first inside the tooth. A white spot appears on the enamel where the tooth has started to weaken inside. At this stage, the tooth can repair the weakened area with the help of fluoride and minerals in saliva. But if the decay continues and breaks through the surface of the enamel, the damage is permanent. The decay must be cleaned out and the cavity filled by a dentist. Left untreated, the decay will worsen and destroy a tooth all the way through the outer enamel layer, through the inside dentin layer and down to the pulp or nerve of the tooth.

In young children, teeth that have recently emerged have weak enamel and are highly susceptible to acid decay. A type of decay called baby bottle tooth decay or early childhood caries destroys enamel quickly and is common in children. This type of decay can eat through enamel and leave a large cavity in a matter of months.

Older adults sometimes have chronic caries: cavities that don't seem to get any worse or do so at a very slow rate. Teeth with chronic caries will tend to be darker in color because the edges of the cavities become stained from normal eating and drinking.

Root caries (decay in the roots of the teeth) is more common in older adults. Older adults are more likely to have gums that have receded from years of hard brushing or periodontal disease. They also are more likely to have dry mouth (xerostomia), which increases the risk of decay. Dry mouth is caused by many common medicines. Be sure to ask the doctor or pharmacist if any of your medicines cause dry mouth.

Decay can form beneath fillings or other restorations, such as crowns. Sometimes, bacteria and food particles can slip into a tooth if a filling hasn't been placed properly or if the filling cracks or pulls away from the tooth, leaving a gap.

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space placeholder.Preventing Cavities
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Do you or your family members get cavities frequently? Dental research has identified factors that increase your risk of getting decay. Next time you visit the dental office, ask about your risk factors and discuss the best ways to reduce your risks and limit dental decay.

To prevent your teeth from decaying, you can do two things — strengthen your teeth's defenses with fluoride and sealants, and reduce the number of bacteria in your mouth.

Fluoride strengthens teeth by penetrating the tooth structure and replacing lost minerals to repair acid damage. Everyone should brush with a fluoride toothpaste every day. Dental offices sometimes recommend additional toothpastes, gels and mouthrinses for both children and adults.

Sealants are protective coatings placed over the tops of chewing teeth — molars and premolars. They block bacteria and acids from sticking in the tiny grooves on the chewing surfaces of these teeth. Children should get sealants soon after their teeth erupt into the mouth.

Although you can never get rid of all the bacteria in your mouth, you can control bacteria by brushing regularly and flossing daily, seeing your dentist and dental hygienist regularly for a thorough cleaning and check-up, and reducing the number of times each day that you consume fermentable carbohydrates.

Some prescription mouthwashes (those that contain chlorhexidine) can help prevent decay by reducing the number of bacteria in the mouth. Chewing sugarless gums, especially those with xylitol, can help reduce decay and increase the flow of saliva.

Tooth Whitening

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.What Is It?
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Tooth whitening is a procedure that lightens teeth and helps to remove stains and discoloration. Whitening is among the most popular cosmetic dental procedures because it can significantly improve how your teeth look. Most dentists perform tooth whitening.

The outer layer of a tooth is called the enamel. Every day, a thin coating forms on the enamel and picks up stains. Tooth enamel also contains pores that can hold stains. Whitening is not a one-time solution. It will need to be repeated from time to time if you want to maintain the brighter color.

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space placeholder.What It's Used For
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The most common reasons for teeth to get yellow or stained are aging, tobacco, tea and coffee. All of these can stain the surface of the teeth.

It is also possible to have stains that are inside the tooth. These are called intrinsic stains. For example, intrinsic stains can be caused by exposure to too much fluoride as a child while teeth are developing. Other causes include tetracycline antibiotics. They can stain a child's teeth if taken by a mother during the second half of pregnancy or by a child who is 8 years old or younger. Teeth are still developing during these years.

Tooth whitening is most effective on surface stains caused by age, foods or drinks.

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space placeholder.Preparation
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Cavities need to be treated before teeth are whitened. That's because the whitening solution can pass through decayed areas and reach inner parts of the tooth. If this happens, your teeth could become sensitive. Whitening also will not work on exposed tooth roots, which do not have an enamel layer. Receding gums can cause roots to become exposed. Whitening also does not work on crowns or veneers.

Whitening can be done in the dental office or at home. For in-office whitening, your dentist probably will photograph your teeth first. This step will help him or her to monitor the progress of the treatment. Your dentist also will examine your teeth and ask you questions to find out what type of staining you have and how severe it is.

Whitening in the office may involve two to six visits. Each one is likely to be about 45 minutes long.

When the examination is complete, the dentist or a dental hygienist will clean your teeth. Once this is done, the whitening procedure begins.

For whitening at home, your dentist can make trays to hold the whitening gel that fit your teeth precisely. Home whitening usually takes two to three weeks. Over-the-counter kits also are widely available for home use. Talk to your dentist if you want to use these home products. Be sure to use them according to directions to avoid overuse and possible damage to your teeth and mouth.

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space placeholder.How It's Done
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There are two main types of whitening procedures. Non-vital whitening is done on a tooth that has had root-canal treatment and no longer has a live nerve. Vital whitening is performed on teeth that have live nerves.

Non-Vital Whitening
Vital whitening may not improve the appearance of a tooth that has had root-canal treatment. If this is the case, your dentist will use a different procedure that whitens the tooth from the inside. He or she will place a whitening agent inside the tooth and put a temporary filling over it. The tooth will be left this way for several days. You may need this done only once, or it can be repeated until the tooth reaches the desired shade.

Vital Whitening
The most common type of vital tooth whitening uses a gel-like whitening solution. This product usually contains hydrogen peroxide. You will place the whitening gel in a tray that resembles a night guard or mouth guard. Then you place the tray over your teeth for a certain period of time — anywhere from an hour or two to overnight.

Tooth whitening can be done in the dentist's office or at home. In-office (chairside) whitening allows your dentist to supervise the process — and your progress — more closely.

In-office whitening usually takes 30 to 90 minutes. You will need at least two or three appointments with your dentist. The number of visits required will depend on the type of discoloration and how white you want your teeth to be.

Your dentist will start by asking about your medical history to learn how your teeth became discolored. Different types of stains will respond differently to the treatment.

Your dentist will apply a special protective gel, then the whitening agent. The most common substance used for in-office whitening is hydrogen peroxide.

Some whitening agents are activated by special lights or by heat. After the whitening agent is applied, the dentist will shine the light on your teeth for a short time. Some dentists have started to use lasers instead of a light or heat. Consumers like the high-tech aspects of laser treatments, but the technology is still too new — and too expensive — to justify its general use. The American Dental Association states that while the technique may be safe, there are no published data on the safety or effectiveness of using lasers for tooth whitening.

If your teeth are badly discolored, you may need more extensive whitening than can be done in the office. Or you may decide you would prefer to whiten your teeth at home.

For in-home whitening, your dentist will take impressions of your teeth and will make one or two custom mouthpieces to fit you. The number will depend on whether you are having both upper and lower teeth whitened. It is important that the mouthpiece fit well. A close fit helps the whitening agent to remain in contact with your teeth instead of irritating your gums. Over-the-counter mouthpieces are unlikely to fit correctly. They can cause gum irritation if the whitening agent seeps out.

At home, you will fill each mouthpiece with a whitening gel your dentist provides. You will wear the mouthpiece for several hours every day. Many people achieve the amount of whitening they want within a week or two. However, you may need to wear the mouthpiece for four weeks or longer.

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space placeholder.Follow-Up
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Your dentist may want to see you a few days after in-office whitening to check your gums. If your gums were exposed to the whitening agent, they can become irritated. If you are whitening your teeth at home, your dentist will want to make sure the process is working properly, usually after a week.

Whitening is not a permanent solution. The stains will come back. If you smoke or consume a lot of staining foods or drinks, you may see the whiteness start to fade in as little as one month. If you avoid these sources of staining, you may not need another whitening treatment for six to 12 months.

Re-whitening can be done in the dentist's office or at home. If you have a custom-made mouthpiece and whitening agent at home, you can whiten your teeth as frequently as you want to. You should discuss your whitening schedule with your dentist. You can talk about what whitening products would work best for you.

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space placeholder.Risks
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Whitening is unlikely to cause serious side effects, although some people's teeth may become more sensitive for a short while. You may get mild gum irritation as well. Whitening procedures should not be done while a woman is pregnant. The effect of the whitening materials on the development of the fetus is not known. Since the procedure is cosmetic, it should be postponed until after delivery.

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space placeholder.When To Call a Professional
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If you feel your teeth would benefit from whitening, contact your dentist to discuss the procedure.