There are several options to treat a missing single tooth, one of which is an implant-supported crown. For this treatment, the implant which is placed in your jaw-bone acts like a tooth-root which supports the tooth-crown that is either screwed directly to the implant or cemented to an abutment structure that is screwed to the implant.
The implant placement is a surgical procedure which can take place in two appointments, called a “two-stage surgery” approach, or in one appointment, called a “one-stage surgery” approach. In the two-stage surgery approach: during the first surgical appointment a soft-tissue flap is raised to expose the bone, the bone is drilled and then an implant is placed into the drilled bone. The head of the implant is covered with a cover-screw, the soft-tissue flap is repositioned and sutured to cover the implant and then the surgical site is allowed to heal for 3-6 months. During this time, a tight contact is established between the bone and the implant in a process known as osseointegration, and in which the bone grows around the implant. Thereafter, during the second surgical appointment, the implant is exposed, the cover-screw is removed and replaced with a healing abutment which protrudes through the gums. Then the soft-tissue is allowed to heal around the healing abutment for 2-6 weeks before the restorative phase can begin.
The ‘one stage surgery’ approach combines both of these surgical stages into one surgical appointment. The implant is placed into the bone followed by immediate placement of the healing abutment. The healing period for this approach is 3-6 months after which the restorative phase can begin.
During the first restorative appointment, the dentist updates your dental and medical records and inquires about any post-surgical side effects. The dentist also discusses your expectations for this treatment and then confirms the selected shade for your crown.
The dentist then takes impressions of your teeth and checks your bite. If necessary, the dentist may take radiographs. Upon further examination, the dentist may find that adjacent or opposing teeth require additional treatment prior to the placement of the crown. If this is the case, an additional appointment is scheduled.
Then the dentist examines the surgical site to ensure proper tissue healing around the implant, as well as adequate oral hygiene. If there are issues with either, the dentist may have to reschedule you for this part of the treatment until oral hygiene issues have been corrected. You may be prescribed a mouth rinse to help with oral hygiene.
If the tissues look healthy, treatment may continue. The dentist removes the healing abutment, takes some measurements of the implant area to assist in planning of the next steps of the treatment and then he or she returns the abutment to its place.
At the second restorative appointment, the dentist takes impressions of your teeth with special, custom-made impression trays. The purpose of the impression is to replicate the position of the dental implant and adjacent teeth from your mouth to a laboratory model. This appointment can be scheduled any time after the first appointment, as long as the gums around the implant site are healthy.
Before the impression-taking process begins, the dentist places a piece of gauze at the back of your mouth over your tongue to act as a throat guard. The healing abutment is removed, and an impression coping is gently connected to the implant. The impression coping assists in accurately replicating the 3-dimensional position of the implant relative to adjacent teeth. The placement of the coping may cause some discomfort or mild pain. The dentist takes this into consideration, asking you how you feel as the procedure continues. If the pain is not manageable, local anaesthetic is administered before continuing with the procedure.
The dentist takes a radiograph to make sure the impression coping is properly connected to the implant and that there is no gap between them.
The assistant then fills the custom tray with impression material and the dentist places impression material around the impression coping, places the tray in your mouth and leaves it there for 5 minutes until the impression material has set. Next, the tray with the impression material and impression coping are removed from the mouth and the healing abutment is attached to the implant.
The dentist uses the laboratory model that is made from the final impression to further plan and design your final crown.
At your third restorative appointment, the dentist first checks the crown in your mouth. The dentist places a piece of gauze at the back of your mouth over your tongue to act as a throat guard. The healing abutment is removed and replaced with the crown or final abutment, which is slowly tightened to the implant. As this is being tightened, you may feel some discomfort or pain. Again, the dentist asks how you feel and slows down if necessary. If the pain continues, local anaesthetic may be administered.
Once tightened into place, the dentist checks that the spaces between the teeth are not too open or too tight, and then a radiograph is taken to ensure that the crown is properly connected to the implant.
The dentist then checks your bite and the appearance of the crown. If you are satisfied with the appearance and comfort of the crown, the dentist fully tightens the screw of the final crown, or he or she first tightens the screw of the final abutment and then cements the crown to the abutment. Thereafter, the dentist gives you instructions on how to keep good oral hygiene around the implant crown.
The fourth restorative appointment is a follow-up appointment. The dentist ensures that you are satisfied with the look and function of the crown and checks your oral hygiene. Depending on the type of restoration, the screw of the crown may need to be re-tightened.
After this appointment, long-term follow-up appointments are scheduled at one month, 6 months and one year after crown insertion and then annually depending on your oral condition.
During the annual follow-up appointments the dentist takes radiographs as part of the dental exam in order to examine the bone and adjacent teeth. The dentist also ensures that the implant and crown are stable, not causing pain or discomfort, that the gums are healthy, and that you maintain good oral hygiene.