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 is made by your dentist in the jawbone. After the implant integrates (attaches) to your bone, it acts as a new "root" for the crown that will be replacing 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, and the bone has to be strong enough to hold and support the implant. If there is not enough bone, be 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.
|This person is missing the teeth to the left and right of the two front teeth.|
How Does It Work?
An implant-restored tooth consists of several parts.
The Implant Process
The time frame for completing the implant and crown depends on many factors. When the traditional method of placing an implant is used, the shortest time frame for a complete implant (including surgeries and placing the permanent crown) is about five months in the lower jaw and six months in the upper jaw. However, the process can last up to a year or more, particularly if bone needs to be built up first.
In the traditional method, two surgeries are required, with three to six months between them. During the first surgery, an incision is made in the gum where the implant will be placed. A hole is drilled in the bone, the implant is placed into the hole in the bone, and the incision is stitched closed.
At the end of the healing period, a second surgery takes place. It involves making a new incision to expose the implant. A collar, called an abutment, is screwed onto the top of the implant. The abutment is used to support the crown. A one-stage procedure is now used sometimes for implants. In this procedure, your dentist can place the implants, and place a temporary crown or bridge all in one visit.
The time frame for this one-stage procedure, from placement to permanent restoration varies depending on the specific implant system being used.
Before any work is done, you will visit either a specialist called a prosthodontist or a general dentist who has had advanced training in the placement and restoration of implants.
Your dentist will do a comprehensive examination. During the exam, he or she will review your medical and dental history, take X-rays, and create impressions of your teeth and gums so that models can be made. In some cases, the dentist also may order a computerized tomography (CT) scan of your mouth. This scan will help your dentist determine how much jawbone is available to hold the implants in place, and will show the location of structures such as nerves and sinuses (located above your upper teeth) so they can be avoided during surgery.
If the X-rays show that your jaw does not have enough bone to hold an implant, the dentist can discuss options, such as bone grafting and bone distraction, for building up the bone. If you need one of these procedures, it will take about 4 to 12 months for the bone to be ready for the implant.
First surgery — implant placement
Month 1 (if no bone grafting is necessary)
Month 5 (if bone grafting is necessary)
Once you have enough bone to successfully hold an implant, you will schedule the first surgery, which involves placing the implant or implants in your jaw. A periodontist or an oral surgeon usually does this surgery, and stays in close contact with your prosthodontist or general dentist.
Although there are several types of implants, the most popular type is root-form implants designed to serve as the root of the tooth. They are placed in the jawbone in the space created by the missing tooth.
After the first surgery, the specialist will wait four or five months if implants were placed in the lower jaw, and six or seven months if they were placed in the upper jaw, before placing a healing collar and/or temporary crown. During this time, the bone and the implants fuse.
Second surgery and placement of healing collar and/or temporary crown
Month 4 or 5 (no bone grafting, lower jaw)
Month 6 or 7 (no bone grafting, upper jaw)
Month 8 or 9 (bone grafting, lower jaw)
Month 10 or 11 (bone grafting, upper jaw)
Once the implants have become fused with the bone, you can schedule the second surgery. Your dentist will confirm whether the implant is ready for the second surgery by taking an X-ray. This surgery is simpler than the first. A new incision is made to expose the heads (tops) of the implants. (A)
A. Healing after second-stage surgery
A collar, called a healing abutment (collar), is placed on the head of the implant after it is exposed. This encourages the gums to heal correctly. The collar is a round piece of metal that holds the gums away from the head of the implant. The collar will be in place for 10 to 14 days. If you previously had a removable partial denture, your dentist may adjust it so you can use it during this time. (B)
B. Healing abutments help the gums to heal properly
After the stitches and collar are removed, final impressions are made. These impressions will be used to make models that will look exactly like your mouth. A dental technician will use these models to make the temporary and final crowns.
An abutment and temporary crown are placed on the implant. (C) The abutment is screwed onto the implant and tightened, using special equipment so that it won't come loose. After the abutment is attached to the implant, the temporary crown is placed on the abutment. In some cases, the temporary crown is attached directly to the implant without an abutment. The abutment then is placed later. In other cases, you may get the abutment and temporary crown immediately after the implants are uncovered during the second surgery, and you won't need a healing collar.
The temporary crown will be in place for four to six weeks. The gums will heal around it and will look like the gums around your natural teeth. The temporary crown is made of softer material than the permanent crown. The softer material helps to cushion and protect the implant from the pressure of chewing, and gives the jawbone the opportunity to gradually get stronger.
C. Temporary crowns in place
Placement of permanent crown
Month 5, 6 or 7 (no bone grafting, lower jaw)
Month 7, 8 or 9 (no bone grafting, upper jaw)
Month 9, 10 or 11 (bone grafting, lower jaw)
Month 11, 12 or 13 (bone grafting, upper jaw)
While you are wearing your temporary crown, the permanent crown will be made. It takes about two to three weeks, sometimes less time, to make a permanent crown. The crown can be created from a model of your teeth and gums that includes the implant or the abutment.
The crown can be either cemented or screwed to the abutment.
Crowns held in place by cement may look better because there is no screw hole in the crown to be seen. However, crowns held in place by a screw are easier for your dentist to remove if he or she needs to reach the implant or the tissue around the implant.
Sometimes, an abutment can't be used. In that case, your dentist would attach the crown with a screw.
Permanent abutment in place
Permanent crown in place
Caring for Your Implants
You care for your implants the same way you care for your natural teeth. It is important to brush and floss daily. You will need to visit your dentist every three months for checkups at first, but eventually you can have checkups every six months.
What Will X-Rays Show?
On an X-ray, you will be able to see the implant in the bone, the connection between the implant and the abutment, and the abutment and the crown. Your dentist can look at how the implant, abutment and crown fit together and make sure that there are no problems.
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, which can cause bone loss, and can cause the implant to break.
You should be aware that when implants are used to replace lower teeth, a nerve that runs through the jawbone can sometimes 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.
What Can You Expect From Your Implant?
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. At times 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.
©2002-2005 Aetna, Inc. All rights reserved.
Reviewed by the faculty of Columbia University College of Dental Medicine