Civitali Dental and Prosthetic Center srl

Can a dental implant be rejected?


Dental implants rejection.

Bacterial infection is the most common cause of implant failure. There are several secondary causes that act as co-factors favoring or accelerating the infective processes.

Can a dental implant be rejected? The answer is NO!

In order to answer analytically to such a question, let’s see in details which are the causes that can lead to lose an implant.

Rejection means a reaction of the immune system to something that is recognized as “foreign” (i.e. non-self). This may be an organ or a tissue (as in transplants) or an inorganic element; some people show sensitiveness or allergies to non-noble metals found in jewelry.

Dental implants are made of an extremely particular metal: high-purity, surface-decontaminated titanium. The organism does not recognize this metal as a foreign body. Instead, this structure is accepted as own (self) and an intimate bond is created.

This happens at the cellular level on the implant surface (the process is called “osseointegration”). This metal is being used also in other surgical branches of Medicine, such as Orthopedics, Neurosurgery, Maxillo-facial Surgery, as a substitute of several anatomical parts or for fixation devices. No description can be retrieved in literature about rejection, or even about any adverse reaction caused by titanium.

So, why a dental implant may be lost? Why this event is so often attributed to rejection?

There are four moments when implant failure can occur:

On the days immediately following surgery

On the second surgery, when a small gingival incision is made to access the implant and proceed with the next rehabilitation steps - taking an impression and prosthesis delivering (usually, 2-3 months after implant placement)

When the final prosthesis is delivered (3-4 months after placement)

On the following months/years

Disregarding a small percentage of cases (about 3%) in which a lack of osseointegration is observed, because of factors still not completely understood, the most frequent causes may be described in detail:

On 1, 2 and 4, the main cause leading to implant loss is the same: bacterial infection. The infection of hard and soft tissues surrounding the implant is the most significant cause that leads to implant failure.

Bacterial infection has nothing in common with rejection.

Bacterial infection may be caused by:

A bad preparation to surgery, a non-sterile surgical approach, a wrong preparation of the oral cavity of the patient to surgery

A wrong antibiotic prophylaxis before and after the surgery, and/or a wrong post-surgical behavior by the patient

An inadequate maintenance of the correct home and professional oral hygiene practice over time.

Beyond bacterial infection, the most common and frequent cause of implant failure, there are some secondary causes that often act as co-factors favoring or accelerating infective processes. The most significant ones are:

cigarette smoke

occlusion traumas

Infective processes affecting dental implants are the same involving natural teeth, leading to their loss as can be observed in periodontal diseases (periodontitis or pyorrhea). Implants are structures lacking of the natural defense mechanisms teeth have, since they are not vital. Therefore, while natural teeth (and their supporting tissues) may contrast the periodontal disease for years, implants cannot do the same. Therefore their survival when the patient is suffering from periodontitis is at high risk.

In synthesis rejection is an event no one can be regarded as accountable or responsible for, while responsibility of infection often lies either on the surgeon or on the patient, or both. Attributing implant failure to rejection is a false statement, often used as an alternative to proper and correct information.