Implant-Supported Denture

Implant-supported dentures usually are made for the lower jaw because regular dentures tend to be less stable there. Usually, a regular denture made to fit an upper jaw is quite stable on its own and doesn't need the extra support offered by implants. However, you can receive an implant-supported denture in either the upper or lower jaw.

You can remove an implant-supported denture easily. Some people prefer to have fixed (permanent) crown and bridgework in their mouths that can't be removed. Your dentist will consider your particular needs and preferences when suggesting fixed or removable options.

There are two types of implant-supported dentures: bar-retained and ball-retained. In both cases, the denture will be made of an acrylic base that will look like gums. Porcelain or acrylic teeth that look like natural teeth are attached to the base. Bar-retained dentures require at least three implants. Ball-retained dentures need at least two.

Bar-retained dentures — A thin metal bar that follows the curve of your jaw is attached to two to five implants that have been placed in your jawbone. Clips or other types of attachments are fitted to the bar, the denture or both. The denture fits over the bar and is securely clipped into place by the attachments.

Ball-retained dentures (stud-attachment dentures) — Each implant in the jawbone holds a metal attachment that fits into another attachment on the denture. In most cases, the attachments on the implants are ball-shaped ("male" attachments), and they fit into sockets ("female" attachments) on the denture. In some cases, these attachments are reversed, with the denture holding the male attachments and the implants holding the female ones.

The implants usually are placed in the jawbone at the front of your mouth because there tends to be more bone in the front of the jaw than in the back. This usually is true even if teeth have been missing for some time. Once you lose teeth, you begin to lose bone in the area. Also, the front jaw doesn't have many nerves or other structures that could interfere with the placement of implants.

The time frame to complete the implant depends on many factors. The shortest time frame is about five months in the lower jaw and seven months in the upper jaw. This includes surgeries and the placement of the denture. However, the process can last up to a year or more, especially if you need bone grafting or other preliminary procedures.

Two surgeries usually are needed — one to place the implants in the jawbone under your gums, and a second surgery to expose the tops of the implant. The second procedure comes three to six months after the first.

A one-stage procedure is now used sometimes. In this procedure, your dentist can place the implants and the supporting bar in one step. The success rate of this procedure is high. However, it is moderately less successful than the more conventional two-stage procedure.

Before any work is done, you will visit either a dental specialist called a prosthodontist or a general dentist who has advanced training in the placement and restoration of implants.

During the exam, the dentist will review your medical and dental histories, take X-rays and create impressions of your teeth and gums so that models can be made. In some cases, the dentist may order a computed tomography (CT) scan of your mouth. This allows the dentist to see the exact position of your sinuses (located above your upper teeth) or nerves, and to make sure they will not be affected by the implant placement. A CT scan also may be done to see how much bone is available and to determine the best locations for the implants.

If you are not already wearing a complete denture to replace your missing teeth, your dentist will make you one. You will use this temporary denture until the implant-supported denture is placed. It will take about four visits, spanning several weeks, to complete this denture. By making this temporary denture, your dentist is able to determine the best position for the teeth in the final denture. The temporary denture also can be used as a backup if something happens to the final implant-supported denture.

Once the temporary denture is finished, the surgeon will use a copy of it as a guide to help place the implants in the proper positions. Holes will be drilled in the copy of the denture so that the surgeon can see where the implants should be placed.

Month 1 (if no denture needs to be made)
Month 2 (if denture needs to be made)

The first surgery involves placing the implants in the jawbone. 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, and the incision is stitched closed. After this surgery, you should avoid putting pressure on the implants. You will not be able to wear your temporary denture for about four weeks, and you should avoid eating hard foods during this time. After four weeks, you will be able to wear your temporary denture again. The temporary denture will, however, need to be modified, to make sure it fits properly. It will also be given a soft reline (new lining next to your gums) to help to reduce the pressure on your gums.

After the first surgery, the dentist will wait three or four months if implants were placed in the lower jaw, and five or six months if they were placed in the upper jaw, before scheduling the second surgery. During this time, the bone and the implants integrate (attach and fuse).

Month 4 or 5 (no denture needed to be made)
Month 5 or 6 (denture needed to be made)

Once the implants have become fused with the bone, the second surgery can be scheduled. 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 small incision is made in your gums to expose the tops (heads) of the implants.

A healing abutment (collar) is placed on the head of each 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. The dentists will adjust your temporary denture again and it may be given another soft reline. The reline material will secure the denture to the healing abutments.

About two weeks after the second surgery, the healing abutments will be replaced with regular abutments. Your gums should now be healed enough for your dentist to make an impression of your gums and implants. The impression is used to make a working model of your implants and jaw, which is used to make the denture framework and teeth.

Month 5 or 6 (no denture needed to be made)
Month 6 or 7 (denture needed to be made)

At this point, the metal bar is placed on the implants. You will have the first try-in of your new denture framework to see if it fits properly.

Once the metal bar and the denture framework have been fitted together properly, the teeth are temporarily placed on the framework in wax. The whole denture is then tried in your mouth. If everything works well, the teeth are secured in the denture framework permanently. The bar or ball attachments also will be secured.

You will have to return to your dentist for another visit to have the completed denture inserted. When the denture is inserted, the denture is clipped onto the bar or snapped onto the ball attachments.

At this point, your temporary denture will be given a new reline. This will allow it to be used as a backup denture in case you lose or break your new overdenture.

You will need to remove the denture at least twice a day for cleaning. You also should carefully clean around the implants and attachments.

For the first year, you should visit your dentist every three months for a cleaning and checkup. Your dentist will test all the parts of your new denture to see if they are secure. Even though your denture is stable, it still can move slightly when you chew. This slight movement can cause the denture to rub against your gums, which can cause sore spots. Your dentist will check your gums and also will check the way your top and bottom teeth come together (your bite).

The clip or other attachments on the bar-retained denture usually will need to be replaced every 6 to 12 months. They are made of a plastic material (nylon) and will wear after continued use.

An X-ray will show the implants in the jaw and any attachments to them. Your dentist will take X-rays a few times during the procedure. They help the dentist to see that the implants, abutments and attachments are in the right places.

In addition to the risks of surgery and of the implants failing, a bar-retained denture carries certain risks of its own.

A bar-retained denture needs space on the denture framework for the special attachments that are fitted to the bar. This means that there is less space available on the denture framework for the teeth to be fitted. Because of this the teeth sometimes can come loose from the base. This problem is easily fixed.

Also, when the bar is attached to the implants it is important that the bar is evenly balanced on each implant. Dentists call this a "passive fit." If the fit is not passive, the extra strain on the bar can cause the screws to loosen. If you grind or clench your teeth, it's more likely that parts of the denture will break or that your implants will come loose.

Your implant-supported denture will be more stable than a regular denture. You will find it easier to speak and you won't have to worry about the denture becoming loose or falling out of your mouth. You generally will be able to eat foods you could not eat before. However, you will not be able to chew hard or sticky foods because they can damage the denture.