If this option is chosen, the patient will need a minimum of 4 to 6 implants in the lower jaw to build a prosthesis with 10 teeth. If the patient wants more teeth on the prosthesis, they will need more implants at the back of the jaw (which isn’t always possible due to the bone loss that is common in this area when patients have been missing teeth for a long time).
As bone loss is normally substantial, the prosthesis normally replaces both missing teeth and gums. The prosthesis is made of metal and acrylic or metal and porcelain.
This prosthesis is anchored as far as the patient is concerned (the patient can’t remove it) but can be extracted by a dentist (if it is screwed in) if it were necessary to make adjustments. This option offers more stability and retention than a conventional full denture or overdenture supported by implants.
The patient will have greater chewing strength and the ability to eat a wide variety of foods.
It is been shown that this type of procedure stabilises bone height over time, stopping associated bone atrophy and the aesthetic effects of ageing on the face.
As with other prosthesis, a fixed full prosthesis may break or the screws may come loose. Nevertheless, it is important to note that this type of prosthesis has a proven success rates above 90% over more than 25 years of clinical studies.
This treatment is more expensive, as it requires more implants than an overdenture.
The patient may have difficulties maintaining proper oral hygiene around the denture. In general, this fixed prosthesis is more difficult to clean than an overdenture.
The treatment time is longer than with conventional dentures and requires two surgeries.
How this treatment is done
At the first appointment, photos and x-rays of the patient’s mouth are taken. Sometimes a special study is requested (CT scan), which is done in a specialised centre outside of the clinic. This study gives the doctors a precise view (even in 3-D) of the amount and quality of the patient’s bone, which is a great help in planning their treatment. It may be necessary to create a provisional prosthesis (splint) for the patient to wear while having the CT scan so the dentist can also see where the artificial teeth should go. The surgeon and the dentist, working as a team, decide how many implants, where they should go and how the final prosthesis should be designed.
The implants are put into the jaw during the first operation. The provisional prosthesis cannot be used for 7-10 days so that the gums can heal. Afterwards, the dentist will adjust the provisional dentures (soft relining of the prosthesis) so the patient can wear it while waiting for the implants to be integrated (“soldered” into the bone).
On the lower arch, the bone should heal around the implants for 3 months, after which the patient has the second operation, to make sure the implants are integrated (“soldered” into the bone). In the second operation, the surgeon exposes the implants and inserts a second component that sticks out through the gum (called a healing abutment) and checks that the implants are completely fixed and no bone has been lost.
After waiting 7-10 days, during which time the patient cannot wear the prosthesis in order to allow the gums to heal, the patient must visit their dentist to readjust the provisional prosthesis.
After that, the dentist starts making the permanent prosthesis. These procedures include preliminary impressions, final impressions, wax moulds, metal tests, tooth tests and inserting the prosthesis. After all of the adjustments have been completed to the patient and the dentist’s satisfaction, the patient can start with regular maintenance and re-assessment appointments.
Many patients with fixed prostheses on implants say they are very comfortable and that the replacement teeth feel and function like their own natural teeth.