Dental implants

Implants are devices that replace the roots of missing teeth. They are used to support crowns, bridges or dentures. Implants are placed in your jawbone by surgery. Most of the time, implants feel more natural and secure than other methods of replacing missing teeth, such as dentures.

There are many reasons it’s important to replace missing teeth:

• Having all of your teeth can make you more self-confident. You don’t worry that people notice that you have teeth missing.
• When teeth are lost, the area of the jawbone that held those teeth starts to erode. Over time, you can lose so much bone that you will need a bone graft to build up your jawbone before your dentist can place implants or make a denture that fits properly.
  

  1. An incision is made in the gum where the implant will be placed

• Tooth loss affects how well you chew and what foods you are able to eat. Many people who have missing teeth have poor nutrition, which can affect overall health.
• The loss of teeth can change your bite, the way your teeth come together. Changes in your bite can lead to problems with your jaw joint, called the temporomandibular joint.
• Losing teeth can lead to changes in your speech, which also can affect your self-confidence.

There are several types of implants, including:

• Root form
• Transosseous
• Ramus frame
• Blade form

Root-form implants are the most common type used today. A root-form implant is made of titanium. It looks like a small cylinder or screw. After an implant is placed in the jawbone, a metal collar called an abutment eventually is attached to it. The abutment serves as a base for a crown, denture or bridge.

The key to the success of all implants is a process called osseointegration. This is the process in which the bone in the jaw bonds with the implant. Titanium is a special material that the jawbone accepts as part of the body.

2. A hole is drilled in the bone

The ability of titanium to fuse with bone was discovered accidentally. In 1952, a scientist named Per-Ingvar Brånemark was using titanium chambers screwed into bones as part of his research to discover how bone healed after an injury. When he tried to remove the titanium chambers, he found they had become bonded to the bone.

Dr. Brånemark then did further research into how titanium implants might work. In 1965, the first root-form implants were placed in people. Other types of implants also have been used for the last 30 to 40 years. Many implant systems are available from various dental manufacturers.

Studies indicate that surgical placement of root-form implants is successful more than 90% of the time. When these implants fail, the problems usually occur within the first year after surgery. After that, only about 1% of all implants fail each year.

Implants have become increasingly popular since the American Dental Association (ADA) endorsed them in 1986. Between 1986 and 1999, the number of implant procedures tripled. An ADA survey found that the average number of implants placed by a dentist who does the procedure was 56 per year in 1999, compared with 18 in 1986.

It is now estimated that between 300,000 and 400,000 implants are placed every year in the United States.

Depending on your particular problem, implants can be more expensive than the alternatives (denture or bridge). A basic implant plus a crown can cost between $1,500 and $4,000. The fees will depend on many factors and vary considerably. Insurance companies generally do not cover this cost, although you should always check with your insurer.

3. The implant is placed into the hole in the bone.

While the upfront cost for implants can be more than for other types of restorations, the investment can pay off in the long run. You may not need an implant for every missing tooth. Your dentist can discuss how many implants you will need.

Other benefits of implants include:

• Feel — Because implants are imbedded in your bone, they feel more like your natural teeth than bridges or dentures.
• Convenience — You will not need to worry about denture adhesives or having your dentures slip, click or fall out when you speak.
• Nutrition — You will be able to chew better with implants. Chewing can be difficult with regular dentures, especially ones that don’t fit perfectly. A regular upper denture also covers your palate, which can reduce your sense of taste.
• Self-esteem — Because implants are so much like your natural teeth, you will think about them less. Your self-esteem and confidence will be improved because you will not have to worry about denture problems or people noticing that you have missing teeth. Regular dentures also can affect your speech, which can make you less self-confident when talking with others.

Who Is an Implant Candidate?

If you’re interested in replacing a missing tooth or teeth, dental implants may be an option for you. Not everybody, however, is a good candidate for implants. A good candidate should have the following:

4. The incision is stitched closed.

• Good health
• Healthy gums
• Enough bone to anchor the implants in the jaw — Some people who have lost bone in their jaw still can get implants, but first the bone must be rebuilt using special procedures.
• A commitment to taking very good care of the implanted teeth and surrounding gums — Daily brushing and flossing are essential. Regular visits to the dentist for follow-up are also important.

Some people may not be good candidates for implants. They include:

• Young people whose jawbones have not developed completely
• Pregnant women
• Heavy smokers — Smoking hinders healing in the mouth. It can reduce the likelihood of a successful implant.
• Alcohol or substance abusers
• People who have received high-dose radiation treatment of the head or neck
• People with chronic diseases or systemic problems, including:
  • High blood pressure
  • Diabetes
  • Connective-tissue diseases
  • Hemophilia
  • Significant immune deficiencies

You still may be a good candidate for implants even if you have one of these conditions. It depends on the extent and severity of the condition.

5. After healing, a new incision is made over the implant. A metal piece called a healing cap usually is screwed on top of the implant to guide the tissue as it heals. Later, the healing cap is removed. Then a permanent part, called an abutment (pictured), is screwed onto of the implant. It is used to support a crown.

• People who take certain medicines, such as steroids or drugs that suppress the immune system
• People who severely grind or clench their teeth — These habits can place too much pressure on the implants and increase the risk of failure.

Your dentist can evaluate you to see if you would be a good candidate for implants.

Single-Tooth Implants - When Is This Used?

Single-tooth implants can be used in people who are missing one or more teeth. An implant is surgically placed in an opening that your dentist makes in the jawbone. After the implant integrates (attaches) to your bone, it acts as a new “root” for the crown that will replace your missing tooth. A crown (cap), which is made to look like a natural tooth, is attached to the implant and fills the space left in the mouth by the missing tooth.

For this procedure to work, there must be enough bone in the jaw. The bone has to be strong enough to hold and support the implant. If there is not enough bone, it may need to be added with a procedure called bone augmentation. In addition, natural teeth and supporting tissues near where the implant will be placed must be in good health.

How Does It Work?

An implant-restored tooth consists of several parts.

• The implant, which is made of titanium, is placed in the upper or lower jawbone.
• The abutment can be made of titanium, gold or porcelain. It is attached to the implant with a screw. This part connects the implant to the crown.
• The restoration (the part that looks like a tooth) is a crown. It usually is made of porcelain fused to a metal alloy (PFM), but also could be all metal or all porcelain. The crown is attached either to the abutment or directly to the implant. It can be screwed or cemented onto the abutment. If the crown is screwed to the abutment, the screw hole will be covered with restorative material such as tooth-colored filling material (composite).

In addition to the risks of surgery, there is the possibility of the implant failing. An implant can fail if an infection develops, which is very rare, or if you clench or grind your teeth. Clenching or grinding teeth puts a lot of pressure on the implant. This can cause bone loss, and can cause the implant to break.

6. The crown, which is made to look like a natural tooth, is cemented or screwed onto the abutment.

You should be aware that when implants are used to replace lower teeth, a nerve that runs through the jawbone sometimes can be injured when the bone is being drilled or the implant is being placed. This can cause numbness or tingling. If this happens, it usually involves the lower part of the lip and chin or one side of the tongue. The numbness can be temporary, until the nerve heals, or it can be permanent. However, it is not common for the nerve to be injured. X-rays and computed tomography (CT) scans can help your dentist to see where the nerve is located and minimize the possibility of injuring the nerve.

In the upper jaw, there is a risk of drilling through the jawbone into one of your sinuses (located above your upper teeth) or nasal cavity, which could cause an infection. To avoid this, special X-rays are taken before your surgery to help your surgeon to determine where your nerves and sinuses are located.

Single-tooth implants will work and look like your natural teeth. However, for some patients, it will be difficult to make the implant look exactly like your natural teeth. In some cases, your implant will not be placed straight, but will be inserted on an angle in the bone because of the amount of bone that you have and the amount of bone that is needed to place the implant properly. A crown placed over an implant that is at an angle may not appear as natural as your own tooth. However, it will typically give you a very good result. Another situation in which it may be difficult to match the appearance of a natural tooth is when the crown is made more bulky to close a space. Studies so far have shown that these implants can last as long as 25 years.