Failures in implantology
- Introduction
In 20 years, implantology has established itself as an essential discipline in dental practice. The success rates of implants commonly reported in the literature are around 95% in most indications.
However, 95% success is not 100%, this means that approximately 5% of implants are affected by failures. These failures are all the more badly experienced by patients and practitioners as they are rare. This obliges us to know them better in order to better avoid them.
- Classification of failures
A classification will guide us in their description. They can take place during:
– preparation of the treatment plan
– of the surgical phase
– from the healing phase
– from the prosthetic phase
– of the function of the implant.
- Failures and complications initiated during treatment preparation
These are errors related to an incomplete anamnesis concerning bruxomania, a systemic disease (bone metabolism disease, uncontrolled diabetes) or an unexpected rare disease.
The operation was without complications. Osteointegration was not achieved at the end of the 3-month healing period. A careful analysis of the cause revealed fibrous dysplasia, a disease hidden during the anamnesis.
- Failures and complications initiated during the surgical phase
Any implantology procedure requires precise knowledge of anatomy and surgical principles. Preparation for the procedure and a precise operating technique,
atraumatic and preserving the tissue environment are of the utmost importance.
Failures in implantology
- Mandibular canal rupture
It can lead to significant sensory disturbances. The risk of damage to the lower dental nerve must be constantly kept in mind, which is why a safety distance of 2 mm above the mandibular canal is introduced. If the break-in is observed, the positioning of the implant must be corrected immediately.
- Heating of the bone during drilling .
Too high a temperature rise above 47° degrees for 1 minute causes fibrous encapsulation at the bone-implant interface.
- Excessive compression of the bone ,
- Lack of asepsis during surgery
- Primary stability defect
Over-drilling of the implant site decreases primary stability. An inadequate biomechanical environment causes mesenchymal cells arriving at the implant site to differentiate into the fibroblastic lineage and not the osteoblastic lineage
- Incomplete screwing of a cover screw or healing abutment
This event may have no consequences, but it may also cause tissue necrosis or local infection.
- Undetected fenestrations or dehiscences
The bone defect itself is not a problem if it is detected during placement because different techniques are available to fill the bone deficiency (bone graft, guided bone regeneration). On the other hand, if it has not been identified, it can lead to fibrous encapsulation.
- Implant malposition
The implant is placed in a position dictated by the presence of available bone quantity and not by prosthetic needs.
Failures in implantology
- Failures and complications initiated during the healing phase
- Uncontrolled forces exerted on the implant
The patient exerts excessive forces on the implant head. This can occur when compulsive repeated pressure is applied with the tongue or when hard food is introduced too quickly after surgery. Another cause is due to the temporization prosthesis touching the implant and exerting forces on the healing abutments.
- Infection
The patient neglects his hygiene and inflammation of the gum and hard tissues occurs. It affects the bone mass. The first stage, mucositis, is reversible, it does not affect the bone surrounding the implant. On the other hand, peri-implantitis causes bone loss, which can ultimately compromise the implant’s prognosis. Many studies have shown the bacterial origin of the pathology, the flora of which is similar to dental periodontitis. Treatments and preventive measures are similar to those used in periodontics: cleaning of the sites, antibiotic therapy, filling with biomaterials, motivation to maintain appropriate hygiene.
- Failures and complications initiated during the prosthetic phase
At the end of the healing period, the prosthetic phase is initiated. Errors during this phase can lead to failure or complication
- Prosthetic sealing with cement rocket in the sulcus
The presence of cement causes chronic irritation to the bone or gum, peri-implantitis can develop and cause loss of the implant
- Elements screwed with too low a torque
Abutment screws or occlusal screws are improperly tightened, below the manufacturer’s recommended torque. Loosening may have minor consequences, however it may also result in component fracture requiring implant removal
- Occlusal overloads
They are the result of a lack of occlusion balance. Prematurity concentrates high stresses at one point, they induce bone lysis which can lead to loss of the implant.
- Failures and complications initiated during implant function
- Aesthetic failures
Aesthetic failure is difficult to correct. A rigorous pre-implant prosthetic analysis can help avoid this pitfall: study models, diagnostic wax, assessment of bone volume. A connective tissue graft by tunneling can restore gingival volume compatible with satisfactory aesthetics.
- Mechanical failure: implant fracture
This is the most serious prosthetic complication because it can compromise the prosthetic restoration.
Failures in implantology
- Conclusion
The placement of dental implants must be considered a delicate surgical procedure which presents risks of complications.
Dental implants are only indicated if the risks of complications are minimal. The therapeutic benefit-risk ratio must always be evaluated and explained to the patient.
Dental crowns are used to restore the form and function of a damaged tooth.
Bruxism, or teeth grinding, can cause premature wear and often requires wearing a splint at night.
Dental abscesses are painful infections that require prompt treatment to avoid complications. Gum grafting is a surgical procedure that can treat gum recession. Dentists use composite materials for fillings because they match the natural color of the teeth.
A diet high in sugar increases the risk of developing tooth decay.
Pediatric dental care is essential to establish good hygiene habits from an early age.