Indications and contra-indications for dental implants
Dental implants serve as artificial roots which can act as supports for the replacements of missing teeth.
In principle, anyone with one or more missing teeth can receive implants, knowing that there are other alternatives such as partial or complete removable prostheses or conventional fixed prostheses.
If a person with completely false teeth has problems because they are loose and interfere when eating, talking, laughing or kissing, or for other reasons such as nausea reflexes or the psychological inability to use them even when the false teeth are firmly in place, then this is a reason to choose prostheses based on implants, either fully fixed or using an overdenture.
An overdenture is a removable prosthesis held in place by a number of implants.
Other important indications are missing rear teeth when patients do not want to use a prosthesis with ‘clasps’, or when there are intermediate gaps and despite being able to have a fixed component supported on their teeth they do not want to have their own teeth ground, which is unfortunate if these teeth are also intact.
Before installing implants the mouth must be healthy, without plaque or tartar, with all cavities filled, without any infected areas, healthy mucous membranes and any periodontal disease (pyorrhea) under control.
The first contra-indication arises from unrealistic expectations on the part of the patient. For this reason it is necessary to make a serious study and inform the patient of the problems related to their case, knowing what can be achieved in terms of function and appearance, and any limitations they may have.
Patients with serious systemic illnesses, major mental disabilities (due to the added difficulty of keeping the implants clean), drug habits (including heavy smokers and alcoholics) should not have implants. It has been demonstrated that implants fail more frequently with smokers. It is very important that the patient does not smoke, or smokes less than 5 cigarettes a day. Tobacco reduces the blood flow to the oral tissues (bone and gums), reducing the amount of oxygen supplied to the region, posing a risk to the osseointegration of the implants.
It may be more difficult for us to install implants in people with highly retracted jaw bones or poor quality bone, as they occupy a certain amount of space and require a minimum width and height. In these cases, it may be necessary to previously fit a bone graft.
At the back of the upper jaw, very low maxilliary sinuses (hollow spaces on both sides of the nose) may also hinder fitting implants. In the lower jaw, the anatomical situation of the inferior alveolar nerve may cause problems due to its proximity to the future implant, making it necessary to reduce the length of the implant or use other techniques to avoid damaging it.
It is also necessary to take into account the patient’s type of bite: patients who clench or grind their teeth at night may cause the implant to fail due to excess pressure. It is therefore important to make as detailed a diagnosis as possible, analysing all of the clinical, functional and aesthetic parameters.