Implants 2

How are implants done?

The implant itself is only one of three components necessary to replace a single tooth.

The implant is placed into the bone, either when a natural tooth is extracted, or at a later date. During this procedure, the dentist cuts the gums and exposes the boney ridge. He drills a hole in the bone the exact size of the implant he plans to use, and then inserts the implant into the hole. Quite often, it is necessary for the dentist to fill in bony defects with demineralized bone grafting material, followed by a collagen membrane. After the implant is firmly in position, and any bony defects are corrected with bone graft material, the dentist then firmly sutures (sews) the gums and membrane over the implant and graft material. The patient is sent home, and the surgical site is allowed to heal for between 4 and 6 months. During this time, the implant attaches directly to the bone (a process called osseointegration), and the demineralized bone graft material is replaced with the patient's own bone.

There is little or no pain associated with actually placing the implant. Most people are surprised to learn that the bone itself has no nerve endings. Only the gums and the periosteum (the thin sheet of tissue covering the bone's surface) have feeling and need to be numb. The procedure can be done giving shots only around the site of the operation itself.

The bone used in many medical bone grafting procedures is treated bovine (cow) bone. The bone is stripped of all protein and organic components and thoroughly sterilized before being packaged. Once processed, the bone contains no trace of its origins, and the human body treats it like its own tissues. When placed in a bony defect, the patient's immune system begins to resorb (remove) the original graft material and replaces it with his or her own bone. This process takes between 4 and 6 months.

Another type of commonly used bone graft is an artificial material which contains small, hollow, porous spheres of plastic coated with calcium hydroxyapatite. This type of graft is called an alloplastic graft. The calcium coating encourages bone growth into the plastic spheres which are incorporated into the newly forming boney matrix in the socket. For more information on bone grafting, click on the toothless skull above.

Between 4 and 6 months after placing the implant, when healing is complete and the implant is totally osseointegrated, the dentist then does a second minor surgery to uncover the implant. This is done with only minimal local anesthesia. Once the implant is uncovered, the dentist then places an abutment into the implant. The abutment is attached to the implant with a tiny screw which is twisted into place with a special torque wrench. The dentist then modifies the shape of the abutment so that it will properly fit into the eventual crown.

Finally, the dentist takes a standard impression, the same as he or she would when fabricating a crown on a natural tooth. This is sent to the lab which returns a porcelain crown which is cemented over the prepared implant abutment.

If the implant was placed in order to retain a removable appliance, such as a denture, the dentist may place a ball abutment instead of a standard abutment. In this case, there is no further modification of the abutment. The denture is either built to snap onto the implant abutments, or an existing denture is modified to fit over the new ball attachment.

What do you pay for when you get an implant?

When you get an implant, you will be paying for each component separately:

You will pay for the implant itself. This includes the surgical procedure necessary to place it in bone. As of 2009, implants generally cost between $1500 and $2500 depending on the area where you live.

To better understand why there is such a wide variation in fees please read this page. It explains why dentists charge what they do and how dental insurance works. It is one of the most important pages on this website.

You will pay for any bone grafting and membrane placement that needs to be done. Whenever an implant is placed immediately after an extraction, bone graft material usually must be forced into the areas of the original socket not entirely filled with the implant itself, and if the gums cannot be closed firmly over the implant and bone graft, a collagen membrane is used to fill the gap. Even when an implant is to be placed into a bony ridge where there has been no natural tooth for many years, bone grafting may still be necessary to fill unexpected bony defects that the dentist could not see on the x-rays. Sometimes, patients are pleasantly surprised when bone grafting is not needed and they do not have to pay this fee. As of 2009, the general range of fees for bone grafting is between $300 and $800 depending on where you live. Some dentists charge this fee per implant, but most charge a single bone grafting fee for multiple adjacent implants if they are done at the same time.
You will pay for the abutment that will be placed on the implant. This fee cannot be avoided, since the abutment is absolutely necessary if the implant is to be used to attach a final restoration such as a crown or denture. As of 2008, abutment fees vary widely, but they range from about $400 to $1000

You will pay for the final restoration. This generally means a crown, which is placed over the abutment. As of 2009, crowns may cost between $800 and $2000 depending on where you live. Sometimes the implant is used to retain a full or partial denture rather than a crown. In the end, all implants must be restored with some kind of final restoration.

Note: Just because a dentist may charge in the high range for the implant, he may not necessarily charge in the high range for the crown, the abutment or the grafting. Likewise, if a dentist advertises a low fee for the implant, he may make up for it with higher fees for the necessary adjunctive procedures such as the grafting, abutment or final restoration.

MDI mini implants for the retention of dentures

The image to the right is a schematic of a lower denture retained in position by four mini implants. Mini implants, unlike standard implants can be placed in the jawbone in a procedure that generally does not involve cutting an incision in the gums. These implants, about the size of a round wooden toothpick, are made out of a very strong titanium alloy which osseointegrates quite well, and are of the sandblasted variety. They do not involve a separate visit or fee to place an abutment, since the abutment is a part of the implant itself. The denture (usually an old denture) is then retrofitted with tiny housings that contain a rubber o-ring made to slip over the implants. The denture then snaps into position over the implants and the patient can wear, and use the denture immediately upon walking out of the office. The cost of this procedure is much less than the cost of placing standard rootform implants, and since the surgery is much less invasive, it can be performed on nearly any patient with nearly any medical condition. Click on the image to read more.

Mini's are not a replacement for regular rootform implants. It takes about 4 mini's to equal the bony support of a single rootform implant. They are simply an economy method of securing a denture that would otherwise be unwearable. Once they are placed, they generally remain firm and function quite well. The major problem with them is their tendency to break during the insertion process if they are placed into very dense, atrophic bone. (Click on the image to the right to learn about atrophic bone.) Mini implants are about the width of a large wooden toothpick, and the process of inserting them involves drilling a small guide hole in the bone and then screwing them into the bone the same way one would twist a woodscrew into a block of wood. Placing a mini implant into bone that retains a lot of its original height is like twisting a screw into a block of pine, but placing a mini into bone that has lost most of its softer alveolar bone due to the loss of the teeth many years ago is like trying to twist a wood screw into a block of oak. The cortical bone that remains years after the the natural teeth are extracted is very dense and difficult to work with. Mini implants are made from a strong alloy of titanium and aluminum, but too much twisting force can cause them to shear off. Of course, broken implants can remain in the bone without damage to the patient, but this complication does not happen when the dentist uses regular rootform implants. The O-ball implant is built to fit into a housing like the one on the left. This housing is cured into the acrylic of the denture base and allows the implant to firmly snap onto the denture.

Mini's are sometimes used to support a single crown (see the square head mini above), but they are useful in this capacity only for very small teeth like lower incisors. Standard rootform implants are more reliable for this purpose. Mini implants have been used to "rescue" large bridges when an abutment tooth has failed, however the best course of action under these circumstances is simply to replace the old bridge with a new, standard implant retained bridge.