Fixed dental prosthesis
For more stable dentures
A dental implant is a screw which is inserted into the alveolar bone that supports teeth. It then acts as an artificial tooth root to adequately hold a dental prosthesis; we call this an “implant-supported prosthesis”.
Indeed, when the implant is stable in the jawbone, a dental prosthesis is made in a laboratory and subsequently installed on the implant. This kind of prosthesis can be attached permanently to the implant.
Removable prostheses on implants are also available. These implant-supported dentures can be removed easily for cleaning and are much more stable than conventional dentures.
To learn more about implantology.
Types of implant-supported fixed prostheses
The following list only covers fixed prostheses that are supported by one or several dental implants, depending on the number of teeth to replace and the condition of the alveolar bone (jawbone) of the patient.
The prosthesis is a simple artificial crown that is mounted on an abutment which is itself screwed into the implant.
It is used to replace a single tooth or sometimes a few teeth, which can be adequately supported by one implant.
This recent technology allows supporting a full denture on 4 implants, both on the maxilla or mandible. The patient should have at least one completely toothless dental arch in order to benefit from this technique.
The technique can even be used in cases presenting bone resorption; a bone graft is, therefore, rarely necessary.
The secret of this technique is the insertion of two implants at a 45-degree angle in the lower jawbone, which gives them greater stability. The installation of the implants and the prosthesis is done in a single visit at the dental clinic. The All-on-4® technique less invasive and the recovery time is shorter than for other treatment plans.
The cost of this treatment plan may be lower because it requires fewer implants.
Implant-supported bridges are also used to replace a single tooth as well as a full dentition.
It is an alternative to the resin-bonded bridge (also called a Butterfly bridge, which is permanently fixed to adjacent natural teeth). The implant-supported bridge is used when the teeth on each side of the edentulous space are not healthy enough to support a bridge or in those cases where too many teeth are missing to be able to attach a traditional bridge.
If natural teeth are adjacent to the bridge, these are not modified (filed down) as in the case of a traditional Butterfly bridge. Natural teeth are thus preserved intact a little longer.
This technique is used to permanently install complete dentures. Although 4 dental implants may be sufficient to support a full denture, especially with the technique All-on-4®, it is sometimes indicated to proceed with the insertion of five, six, eight or even ten implants.
The number of implants needed is mostly influenced by the jawbone quality and quantity, as well as its stability (its resorption must be stopped or slowed down with the help of your dental health professional).
Usually, a larger number of implants will be required if:
- The amount of bone is insufficient or the bone quality is inadequate;
- The stability of the prosthesis is important to you;
- The stimulation of the alveolar bone must be as important as possible to avoid serious problems of bone resorption.
It is common to use 8 implants or more to support a full denture on the upper jaw. Fixed dentures on the lower jaw rarely require more than 6 implants.
The main disadvantage of this technique is its higher cost due to the important number of implants.
Candidates for dental implants
- A person of any age who has undergone partial or total tooth loss due to several reasons such as an accident, a congenital condition, old age or poor oral hygiene.
- A person with no significant health problems (e.g.: heart problems represent a contraindication to the surgery required for the installation of dental implants.)
- A patient with an appropriate amount of jawbone to support the implants; a bone graft is sometimes possible to restore the quality and quantity of bone needed before proceeding with the installation of implants.
Dental health professionals involved
- Oral and maxillofacial surgeon;
- General dentist, provided that he or she has a thorough and comprehensive training in implantology.
- Prosthodontist or prosthetist.
Steps and timeframe
Delays of several months are usually required for the installation of implant-supported dentures. These include the healing time of the surgical sites (where dental implants are inserted into the jaw), as well as the time required for the fabrication of the fixed prosthesis, depending on where the prosthesis is produced (on site at the clinic, in an external laboratory, etc.).
The treatment involves several steps. The main ones are summarized below.
Consultation with a dental professional: during this first visit, information is collected using a questionnaire about your medical and dental history, a clinical examination of your mouth, X-rays, scans (if necessary) and photos. This appointment will first determine if you are a candidate for dental implants.
Preparation of the gums and/or alveolar bone (gum graft or bone graft), depending on your case, especially if the volume of gingiva or jawbone that will receive the implants is insufficient. If this step is required, additional delays should be expected to allow for full recovery of your gums or bone before proceeding to the next steps.
Preparation of a temporary prosthesis using models of your teeth and jaws, if necessary.
Surgical and prosthetic steps
Installation of dental implants into the jawbone according to the number of teeth to replace, the condition of your jaw and the technique used to fix the prosthesis. The longest delay in the full process of replacing teeth by implant-supported dentures varies from 3-6 months and is expected as a result of the installation of implants. This period of time is necessary for the completion of the osseointegration process, i.e. the firm anchoring of the dental implant by the growth of bone around it.
Installation of the abutment, which is screwed on each dental implant. After a variable length of time, depending on each case and on the technique used, each abutment will serve as a support to fix the prosthesis on the implants. This procedure can be performed in two ways, depending on the technique used by the surgeon:
- Immediately after the installation of dental implants, during the same surgery.
- When implants have fused to the alveolar bone; in this case, two surgeries are required.
Fabrication of the dental prosthesis in a laboratory (on-site or external lab). If several teeth are missing or even sometimes for a single missing tooth, you can wear a temporary prosthesis while the final one is being made using photos and dental models. This temporary dental prosthesis will enable you to chew normally and avoid walking around with no teeth during the osseointegration process and while you are waiting for your final dentures.
Installation of the final prosthesis. This step sometimes requires several adjustments or corrections to optimize your comfort and get a perfect fit of your implant-supported dentures. If the abutment is installed at the same time as the implant, it is sometimes replaced by a permanent abutment at this stage. If the abutment is only installed after the osseointegration, the permanent abutment is installed after exposing the implant (by making an incision in the gingiva that is covering it).
Benefits of implant-supported dentures
- The implant-supported fixed prosthesis allows for normal mastication as well as improvement of the smile and harmony of the face.
- A fixed prosthesis is comfortable and discreet because no unpleasant friction is generated by the prosthesis (unlike conventional dentures).
- Usually, upper dentures that are supported by dental implants do not cover the palate, making them less bulky. They do not impede speech nor alter the taste of food.
- There is a very low risk of implant rejection by the human body. Titanium is the most used material for implants and is biocompatible. This results in a very high treatment success rate.
- An implant-supported fixed prosthesis is the most permanent, reliable and long-term solution for the replacement of one or more teeth. Once osseointegration is complete, the implants can stay in the bone for a lifetime.
- The prosthesis that is mounted on implants can be replaced when it is damaged, normally after several years of use. The best person to check the condition of your prosthesis is your oral health care professional. Replacement requires additional fees, but these are, of course, smaller than those required for the initial installation of implants.
- Dental implants prevent jawbone loss and deterioration by stimulating the bone and thus limiting its resorption. On the other hand, conventional dentures (that are not implant supported), do not have this beneficial effect on the jawbone.
- Implants allow distributing chewing forces equally between implants and adjacent structures (gums, bones and remaining teeth), which helps to reduce the stress on the latter.
- The installation of a fixed prosthesis on implants requires no changes to the structure of the adjacent teeth (ex.: filing down of the enamel), compared to a traditional bridge that is not implant supported.
- Your smile (final result) is predictable by the colour and the shape given to the artificial teeth so that they blend completely with the remaining dentition.
- The implant-supported fixed prosthesis is very stable. Therefore, the use of an adhesive is not necessary.
- After your treatment, you are not forced to change your diet on a permanent basis, as it is often the case with removable dentures that are not implant supported.
- The implants and the prosthesis attached to them cannot be affected by tooth decay.
Disadvantages of implant-supported dentures
Compared to other alternatives like conventional removable dentures, the implant-supported prosthesis represents a significant investment of money. However, keep in mind that it is well worth it because these prostheses have a long life span.
The time required to complete the treatment plan for implant-supported dentures is much longer than the period required to make conventional dentures or partial dentures.
As a surgical procedure is required for the installation of implants, this treatment is more invasive than other treatments.
Dental implants can be contraindicated for certain patients with specific medical or anatomical conditions.
For those of you who have lost one, many or all of your teeth, implant-supported fixed prostheses are designed to improve your quality of life in the following ways:
- They restore normal masticatory function;
- In the case of fixed partial dentures, they reduce the impact of masticatory forces on remaining teeth;
- In the case of fixed partial dentures, they ensure stability of remaining healthy teeth and avoid movement towards toothless spaces;
- They improve speech (phonetic) (particularly for sounds including consonants articulated with the tongue against the upper teeth);
- They give you a beautiful smile.
Costs vary widely depending on the technique used, the number of implants required, the type of final prosthesis, etc.
Consult your dental health professional to find out about the cost of the treatment plan that is adapted to you.
A portion of the costs for the fabrication of an implant-supported fixed prosthesis is reimbursed completely or in part by some dental insurances.
Things to know before the treatment
- No dental treatment plan is permanent. You may need adjustments to your fixed prosthesis or replace it after some time.
- Ask yourself what are your treatment goals and what is the desired outcome.
- Identify your concerns about the treatment to be able to discuss them during your initial consultation.
- Certain conditions (ex.: medical conditions) can represent contraindications to the installation of dental implants. The most frequent are major allergies, young age, organ transplants, autoimmune or immunodeficiency diseases, osteoporosis, cancers (in progression or treated by certain types of drugs or treatments), cardiovascular diseases, smoking, drug addiction, alcoholism, pregnancy, uncontrolled diabetes, taking anticoagulants, some psychiatric problems, bruxism, unfavourable anatomy, poor oral hygiene, an infection, or even some dental malocclusions. Therefore, it is important to be aware of your oral health and physical condition, as well as all the diseases that you have been diagnosed with in the past.
Risk of not intervening
- Undesirable changes in the appearance of your face and in your masticatory function.
- Irreversible jawbone resorption where one or more teeth are extracted or already missing.
- Shifting of the remaining teeth towards the space left by missing teeth if this space is not quickly occupied by a prosthesis.
No guarantee can be offered by the professional who installs dental implants and makes your prosthesis for the following reasons:
- Just like any part of the body, the mouth is constantly evolving and changes throughout life.
- Osseointegration can fail for different reasons, often out of your control, which results in the replacement of the implant that has not fused to the bone.
- The longevity of your fixed prosthesis closely depends on how you maintain it. However, you should know that a prosthesis must often be replaced after 5 to 10 years of use.
Alternative solutions to implant-supported prostheses
Depending on your medical condition, other treatments may be possible, such as:
- Removable prosthesis without implant (denture or partial);
- Removable prosthesis on implant;
- Any other solution as suggested by your oral health professional.