But how much do you know about the implants?
Different implant systems or brands have different connections and configurations, but most of them have similar components or parts. The part that is often called the implant or the fixture, is the titanium screw that you see on the left.
The first stage of implant surgery is always to place the fixture into the bone. Obviously, the implant practitioner cannot just drill into the jaw bone blindly. He/she must look at xrays and determine a safe region in the jaw to place the fixture without perforating bone and causing any damage to vital structures.
After a hole is drilled in the jaw bone, the surgeon selects an implant of appropriate length and diameter and then proceeds to drive the implant into the bone. If bone width and quality are good, the implant will present good initial or primary stability. Implants which have gained good initial stability even before they have fused with the bone have a 98% rate of successful integration.After implant placement, a healing period must be allowed. For the lower jaw, this is usually 2 months. For the upper jaw, it is usually 3 months. For bone grafted implants without good initial stability, it may take 6 months or more.
Once the implant practitioner is quite certain that the fixture has integrated with the bone, he/she will proceed to the next stage of implant restoration.
If the surgeon is confident of the bone quality and done a one stage surgery, an abutment can be directly connected to the implant. If the implant fixture has been covered with gum during the surgery, it must first be surgically exposed before the abutment is connected.
After connection of the abutment, it will be obvious that the implant is present even though it is hidden beneath the gums. The abutment projects from the gums and forms a pillar of sorts for the fabrication of a crown. There are many ways in which the restoring dentist can prepare the crown. The simplest and most straightforward method is to take an impression of the abutment and then cement a crown over it. Another method is to build the crown into the abutment itself and screw the crown-abutment complex into the fixture. These crowns are screw-retained instead of being permanently cemented.
Cemented crowns are can be very economically fabricated, but once permanently cemented, there is no turning back. Screw-retained crowns and bridges can be removed by the dentist for periodic maintenance. However, they are more costly to produce.
In an ideal situation, the crown covers over all the metal of the abutment. This situation is not always sustainable. Metal may be exposed due to wear or to bone resorption after several years.