IMPLANTOLOGY
GENERALS
Oral implantology is the branch of dentistry that deals with replacing missing teeth with as many synthetic titanium screws anchored in the bone as to support single teeth, groups of teeth or serving as a support for a complete prosthesis (the so-called dentures).
It must be remembered that the use of the implant solution allows to keep the natural teeth close to the space to be filled intact as the construction of implant based teeth doesn't involve natural teeth with preparations that compromise their integrity or by using them as supports for hooks or attachments that very often reduce their stability.
Modern scientific research tells us that implants can be placed at any time: either immediately after extraction or years later, as long as the residual thickness of the bone is sufficient to guarantee their stability. However, the most predictable results are obtained when all the bone needed is already in place.
THE TITANIUM IMPLANT
Titanium is a metal characterized by high tolerability, so much so that it is commonly used in the production of orthopedic prostheses.
Titanium implants are threaded artifacts resembling a normal screw, mostly cylindrical or conical, of various length and diameter to be able to adapt to different configurations of the bone segment available for their insertion.
Their surface is treated in such a way as to enhance the possibility of osseointegration (attachment to the bone). Dental implants must be produced and packaged in accordance with European law and are therefore accompanied by a certificate that can be viewed and kept by the patient as a guarantee.
Rejection in dental implantology DOES NOT EXIST, as there is no possibility of an unfavorable immunological reaction as happens in heterologous (donor) transplants. Complications concern 4% of cases, in which osseointegration does not occur and the implant is expelled, often accompanied by a local bacterial infection (as can also happen to natural teeth).
CONTRAINDICATIONS
It is necessary to clarify the main reasons why an implant surgery can fail or is even contraindicated.
a) Patients who have not been successfully educated to a high standard of home oral hygiene, or who do not consent to a professional regular check of their hygiene, cannot undergo dental implantology. This is because the resistance to infection caused by the bacterial plaque of an implant - tooth unit is much lower than that of a natural tooth, as their supporting apparatus is different.
The root of a natural tooth is in fact connected to the bone with the periodontal ligament, which is absent along the titanium cylinder which, in fact, is osteointegrated, that is, it connects directly to the bone with an ankylosis process.
The dental and implant support bone is particularly vulnerable to infection but, in the case of implants, it is only defended by the gingival sleeve that surrounds the collar. Again for the same reason, once the bacterial plaque has passed through the gingival gate, it speeds rapidly along the implant, spreading the infection to the deep bone.
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b) Patients suffering from systemic diseases, non-compensated diabetes, coagulation disorders or undergoing radiotherapy should not undergo implantology.
Generalized osteoporosis is not an absolute contraindication because in reality the jaw is mostly spared from this pathology. In these cases the failure is predictable a priori and therefore we should rather speak of the impossibility of success already at the diagnostic level to avoid operational failure.
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c) The use of some drugs used in osteoporosis therapy (bisphosphonates) but also, at higher doses, as adjuvants against metastases in oncology, is a contraindication to implantology. These drugs slow down bone metabolism to such an extent that osseointegration is difficult and also expose the risk of infectious necrosis more. The implants can still be applied after an appropriate period of suspension.
PATIENT PREPARATION
The most suitable examination in modern times to make a pre-implant evaluation is Cone Beam Computed Tomography (CT-Cone Beam). On op day, it is advisable to be at rest without undergoing physical stresses, and a cover antibiotic therapy may be eventually started the same day.
It will be a good idea to warn the dentist if you regularly take medications, such as anticoagulants (cardioaspirin, Coumadin, etc) so that the therapy can be adjusted, if necessary, in the days immediately preceding the surgery.
In the first week after implantation it is preferable not to smoke and not to drink alcohol, not to chew on the wound and to brush the other teeth regularly, avoiding traumatizing the operated area. Same procedure is carried out in the following weeks, taking care to promptly notify the dentist in case any alteration in the area is noticed, or if pain occurs.
THE SURGERY
The surgery is performed under local anesthesia and is completely painless. Depending on the situation and the implant model, the actual operation can be done in just one time by leaving the head of the implant outside gum level, or in two stages (the second time being much simpler and shorter than the first: a small gingival incision used to expose the implant's head).
After the surgery, it is necessary to wait for a variable time and in any case not exceeding four months in order to proceed with the prosthesis or implant loading with an artificial tooth.
The connection can take place in various ways, depending on the type of implant, the patient's needs and the habits of the prosthetist and mostly consists of screwing or cementing.
Modern implant techniques include the so-called immediate loading; it is a method with which the patient receives a temporary tooth immediately in the same session in which the implant is inserted. Although very interesting regardingpatient's comfort, this technique still involves several critical issues, being that during the first month of integration, the implant actually undergoes bone remodeling which reduces its primary stability (which is recovered in the following three months). Therefore, loading the tooth into chewing since its insertion must be done with extreme caution.
MAINTENANCE AND DURATION
After the restoration it will be necessary to regularly clean the teeth with a toothbrush and toothpaste after each meal, and at least once a day to use dental floss to avoid the accumulation of plaque on the bridge elements and on the collars of the implants, then rinsing the mouth with mouthwash .
Compliance with these simple rules is a guarantee to keep the gums and therefore the implants in good health for a long time. The duration of the work will depend on the application and daily commitment to oral hygiene.
The systems have a very long life (the studies carried out to date reach 25 years but the prospects are even greater) if daily maintenance is carried out: the biggest risk that the systems run is given by:
peri-implantitis: inflammation and infection of the structures around the implant, resulting in loss of osseointegration
incorrect loading of the implants themselves, with incorrect crowns or prostheses, which can create bone resorption over time, with bone loss up to the deepest threads of the implant and therefore with the possibility of loss of the same.
To avoid these possible implant failures it is therefore necessary to have a good prosthesis, fixed or mobile, well balanced from the point of view of occlusion (correct chewing balance), to have good daily oral hygiene and to carry out periodic check-ups. It should also be mentioned that smoking can compromise both osseointegration and the duration of the implants.