X-Rays

What Are X-Rays?

X-rays are a form of energy that travels in waves. X-rays can enter solid objects, where they either are absorbed or continue to pass through. X-rays tend to be absorbed by denser objects. They pass easily through less dense objects.

Teeth and bone are very dense, so they absorb X-rays. X-rays pass more easily through gums and cheeks. That's why cheeks and gums appear dark and without detail on a dental X-ray, but teeth show up much lighter. Restorations such as crowns and fillings are even denser than bone. They show up as solid, bright white areas on X-rays. Dental decay and caries (cavities) appear as darker patches.

What You See on an X-Ray

How Often Should You Go to the Dentist?

More than 50 years ago, examinations of people entering the military showed that Americans' teeth were in pretty bad shape. Few people took good care of their teeth. There were no guidelines for how often you should see a dentist. Many dentists focused on fixing problems rather than preventing them.

Dental and health organizations decided there was a need to set standards for preventive dentistry. They didn't have much evidence, so they made a "best guess" recommendation. They said people should go to the dentist twice a year for checkups and cleaning.

This proved to be a useful rule of thumb and has remained common. Even if you take excellent care of your teeth and gums at home, you still need to see your dentist regularly. Your dentist can check for problems that you may not see or feel. Many dental problems don't become visible or cause pain until they are in more advanced stages. Examples include cavities, gum disease and oral cancer.

Regular visits allow your dentist to find early signs of disease. Problems can be treated at a manageable stage.

On average, seeing a dentist twice a year works well for most people. A few people can get away with fewer visits. Others may need more frequent visits. People with very little risk of cavities or gum disease can do fine seeing their dentist just once a year. People with a high risk of dental disease might need to visit every three or four months, or more. This high-risk group includes:

* Smokers
* Diabetics
* People with current gum disease
* People with a weak immune response to bacterial infection
* People who tend to get cavities or build up plaque

The schedule for any person may change during a lifetime. In times of stress or illness, you may need to see the dentist more often than usual. The dentist may help you to fight off a temporary infection or treat changes in your mouth.

If you take good care of your teeth and gums at home and your dentist doesn't find any cavities or gum disease for a few years, he or she may choose to lengthen the time between visits. Ask your dentist the best schedule for your routine dental visits.

Your Dental Visit: What To Expect

Types of Dental Visits

Most people are familiar with the typical dental checkup visit. If the office has a dental hygienist, he or she will clean your teeth, do an examination and sometimes take X-rays. Then the dentist will check the X-rays and your teeth for signs of decay, check your gums for changes, and check for signs of oral cancer or other diseases.

From time to time, however, your dentist should do a more thorough exam. This is called a comprehensive examination. It includes a thorough examination of your entire mouth, head and neck area. The dentist also will ask about your medical history, and you will get X-rays if indicated.

A comprehensive examination likely will be done the first time you visit a dental office. Even if you have had regular care under another dentist, your new dentist will want to become familiar with your health. This will allow him or her to notice changes or problems more easily during future visits.

Some activities are standard for a checkup or comprehensive exam, but dentists and hygienists have their own style and skills. If your dentist doesn't do everything listed here, that doesn't necessarily mean he or she isn't doing a good job. If you are concerned, ask why certain things are left out or why others are included.

The order in which things are done may vary as well. And it doesn't all have to be done at every visit.

An important part of every visit is updating your medical history. Your dentist will want to know if you've had any changes in your health or your medicines since your last visit.

Mention everything about your health, even if you don't think it relates to your mouth. Many diseases can have significant effects on your mouth and teeth. Researchers continue to discover ways in which oral health is related to overall health. For example, people with diabetes are at a higher risk of developing periodontal disease. Research also suggests that periodontal infection can affect your blood sugar levels and make your diabetes harder to control. Other health conditions may require your dentist to change the type of anesthesia given.

Bring a list of all medicines you take, with dosages. Some medicines cause dry mouth, which can increase the risk of cavities. Your dentist also will want to check that any drug he or she prescribes doesn't interact with drugs you are already taking.

What To Tell Your Dentist

Your dentist needs to know everything that may help him or her diagnose problems or treat you appropriately. Tell your dentist:

* Your fears — Many people have fears of the dentist that go back to childhood. Pain control and treatment techniques change constantly. The things you fear most may not exist any longer, or there may be new and improved ways of dealing with them. If you fear you have a particular disease or condition, let your dentist know. He or she can look for signs and either diagnose the problem or set your mind at ease. Often, just talking about your fears will take some of the edge off.


* Your overall health — Tell your dentist if you've been diagnosed with any diseases or are taking any new medicines. It is important to tell your dentist about all medicines you take. This includes those that have been prescribed by your physician and over-the-counter medicines. Even diseases that seem to be unrelated to the mouth may require a different approach to dental treatments or prevention.


* Your dental health — If you think you have a new cavity, if your teeth have become sensitive or if you feel lumps inside your mouth, tell your dentist before the examination starts. Don't wait to see if the dentist catches it or silently hope the dentist misses it. By telling your dentist your symptoms, you may help him or her make an early diagnosis.

Oral Cancer

Tobacco's greatest threat to your health may be its link to oral cancer. The American Cancer Society reports that:

* About 90% of people with mouth cancer and some types of throat cancer have used tobacco. The risk of developing these cancers increases as people smoke or chew more or for a longer time.

* Smokers are six times more likely than nonsmokers to develop these cancers.

* About 37% of patients who continue to smoke after cancer treatment will develop second cancers of the mouth, throat or larynx. This compares with only 6% of those who stop smoking.

* Tobacco smoke from cigarettes, cigars or pipes can cause cancers anywhere in the mouth or the part of the throat just behind the mouth. It also can cause cancers of the larynx, lungs, esophagus, kidneys, bladder and several other organs. Pipe smoking also can cause cancer in the area of the lips that contacts the pipe stem.

* Smokeless tobacco has been linked to cancers of the cheek, gums and inner surface of the lips. Smokeless tobacco increases the risk of these cancers by nearly 50 times.

Implant Failure

Implants can replace lost teeth in people who smoke. However, smokers should know they have an increased risk that the procedure will fail.

"Studies have consistently found that patients who smoke have more implant failures," Dr. Albert says. Smokers who are considering getting a dental implant need to realize this risk, he says.

"Before getting implants, consider seeking counseling and support to help you quit smoking," he says.

Smoking: A Danger to Healthy Gums

You've probably seen the warning on cigarette packages: "Quitting smoking now greatly reduces serious risks to your health." What smoking-related diseases come to mind? Lung cancer, probably. Emphysema, maybe.

But did you know that half of periodontal (gum) disease in smokers is caused by smoking? Chronic (long-term) gum disease can lead to the loss of your teeth.

"Studies have found that tobacco use may be one of the biggest risk factors in the development of periodontal disease," says David A. Albert, D.D.S., M.P.H. Dr. Albert is an associate professor at the Columbia University College of Dental Medicine.

Periodontal (gum) disease is a bacterial infection. It destroys soft tissue and bone that anchor your teeth to your jawbones. Bacteria grow in the dental plaque that forms in the pockets around your teeth. Your body's reaction to the plaque leads to the breakdown of soft tissue and bone.

In early stages of the disease, you may notice that your gums bleed when you brush or floss. As the infection worsens, your gums begin to break down. They pull away from your teeth, forming pockets. Later, the pockets between your teeth and gums deepen as more of the supporting structures are destroyed. Ultimately, your teeth may become loose and painful. They may even fall out.

Studies have shown that smokers have more calculus (tartar) than nonsmokers. This may be the result of a decreased flow of saliva. Calculus is the hardened form of plaque.

Smoking tobacco products can make gum disease get worse more quickly. Smokers have more severe bone loss and more deep pockets between their teeth and gums than nonsmokers. In studies, smokers were three to six times more likely to have gum destruction than nonsmokers. Severe bone loss was five times greater among current or former heavy smokers than among people who never smoked.

"Smokers have much less gum bleeding and redness than other people even though their mouths are not healthy," Dr. Albert says. "This can lead to the false impression that the gums are healthy. It is therefore very important that tobacco smokers have regular dental exams to evaluate their gum health."

Not only does smoking increase the chance that you will develop gum disease, it makes treatment much more difficult. And the treatment is less likely to succeed. That's because smoking hinders healing in your mouth.

One study found that smokers were twice as likely as nonsmokers to lose teeth in the five years after completing periodontal treatment. In most studies of nonsurgical gum treatment (deep scaling), smokers improved less than nonsmokers. Smokers also didn't respond as well to surgery. Implants are much more likely to fail in people who smoke, because of poor bone healing.

Crowns and bridges look great when first placed in the mouth. In smokers they often lose this beautiful appearance, especially as the gums recede and bone is lost. Popular cosmetic procedures, such as porcelain laminates, will not look good for a long time in a person who smokes.

Researchers still are studying just what smoke does to mouth tissue. It appears to interfere with basic functions that fight disease and promote healing. Researchers have found that smoking affects the way gum tissue responds to all types of treatment.

"It is believed that the chemicals contained in tobacco interfere with the flow of blood to the gums," Dr. Albert says. "This leads to a slowdown in the healing process. It makes the treatment results less predictable and often unfavorable."

It is not just cigarette smoke that contributes to periodontal disease, Dr. Albert says. All tobacco products can affect gum health. This includes pipe tobacco, smokeless tobacco and cigars.

A study conducted at Temple University showed this risk. Researchers reported that 18% of former cigar or pipe smokers had moderate to severe gum disease. "This is three times the amount found in non-smokers," Dr. Albert says. The study was published in the Journal of Periodontology in 2000.

Experts say pipe smokers have rates of tooth loss similar to those of cigarette smokers. Smokeless tobacco can cause the gums to recede. This increases the chance of losing the bone and fibers that hold teeth in place.

The only good news about smoking and oral health is that the Surgeon General's warning holds true. Quitting now does greatly reduce serious risks to your health. A recent study reported that people who had quit smoking 11 years before had about the same rate of periodontal disease as people who never smoked.

Even reducing the amount you smoke seems to help. One study found that people who smoked more than a pack and a half per day were six times more likely to have periodontal disease than nonsmokers. Those who smoked less than a half pack per day had only three times the risk.

"The dental office is a good place to visit for help with quitting," Dr. Albert says. "Your dentist can show you the effect of smoking on your mouth and teeth. She or he can help you set a quit date and provide you with advice on which medicines can help you quit, such as nicotine patches or gum."

Dental Sealants

What Is It?

A sealant is a clear or tinted plastic protective coating for teeth. It is painted onto the chewing surfaces of the back teeth (molars and premolars). These are the areas where most cavities form.

Molars and premolars have grooves and crevices. Dentists call these pits and fissures. Food can get stuck in these crevices. Some are so deep that the bristles of a toothbrush can't reach into them.

Grooves and crevices provide the perfect environment for bacteria to grow and cause cavities. Sealants help to prevent this from happening. They cover the grooves and crevices so that food cannot get into them.

What It's Used For

Sealants are applied to teeth to help prevent cavities. In the past, they usually were used only in children. But adults also can get sealants. Click here to see illustrations showing how sealants are applied.

Not only are sealants very effective, they cost a lot less than filling cavities.

In children, sealants can be applied to baby molars to protect them from cavities. Eventually, these molars fall out and the new, permanent molars come in. These molars can be sealed, too. Most dentists recommend that sealants be applied to each permanent molar as soon as possible. This can be when the tooth is only partially erupted into the mouth. However, it can be done only if the tooth can be kept dry and free of saliva while the sealant is applied.

If your child has a high risk of cavities, your dentist may decide to seal the premolars, or bicuspids, as well. The premolars are the teeth directly in front of the molars.

Sealants can be used in adults who have an increased risk of developing cavities. Your dentist can suggest whether sealants are appropriate for you.

Sealants can be put on teeth that show early signs of decay. But once the decay has broken through the enamel, the tooth will need a filling.

Preparation

Applying sealants is quick and painless. It can be done during a routine dental visit. No injections are needed. However, it is very important to sit still so the tooth or teeth being worked on will stay dry. This allows the sealant material to stick properly to the tooth.

How It's Done

The dentist cleans the area to remove any food or debris in and around the teeth. Then he or she makes sure the teeth are dry so that the sealant can stick. The sealant is applied in liquid form. It flows over and into the grooves and crevices. The sealant usually hardens (sets) within 20 to 60 seconds. Sometimes it is set with a special light.

Follow-Up

Studies show that sealants can last a long time, sometimes as long as 15 years. But they don't last forever.

The dentist will check the sealants during routine visits. If necessary, the sealants can be replaced.

Remember, sealants work well, but they can't keep teeth cavity-free without some help. Keep brushing twice a day, flossing at least once a day, and visiting a dentist regularly.

Children with sealants still should:

* Brush twice a day with a pea-size amount of fluoride toothpaste.
* Floss between any teeth that touch each other.
* Get the right amount of fluoride, either by drinking fluoridated water or taking fluoride liquid or pills.
* See a dentist regularly

Risks

Although it is rare, sealants can cause problems in people who are allergic to plastics or components of plastics. In addition there has been some concern about the possible harmful effects of bisphenol A (BPA). This chemical is found in some sealants. However, studies show that any release of BPA from sealants is very small and limited to the time right after they are applied. The American Dental Association and the U.S. Food and Drug Administration have found that sealants are safe.

When To Call a Professional

Ask your dentist to talk with you about the benefits of sealants. Most pediatric dentists (dentists who specifically treat children) use sealants routinely. However, not all dentists do so. Therefore, your dentist may not think to talk with you about them.