Implant planning and prosthetic project
Introduction :
Implant planning comes down to choosing the surgical solution based on the chosen prosthetic solution (prosthetic project)
- Definitions
1.1. Definition of implant planning
It is a treatment plan that results from the analysis of all the elements collected by the practitioner during
– The interrogation
– The clinical examination
– Prosthetic simulation
– The study of radiological elements
1.2. Definition of the prosthetic project
This is the preview of the future result to have on the one hand the patient’s agreement, the prosthetist’s consent to the design of the prosthesis as well as the feasibility of the project for the practitioner.
- Different stages of implant planning
2.1. Anamnesis
- Marital status
- Reason for consultation
- General condition; personal and family history
- Studies of photographs (face, profile, etc.).
2.2. Contraindications in implantology
- Absolute contraindications :
- Patients at risk of bleeding;
- Pathologies whose treatment consists of intravenous Biphosphonates.
- Cardiovascular pathologies at high risk of infective endocarditis.
- Severely immunocompromised patients.
- Relative contraindications :
- Diabetes.
- Cardiovascular diseases with medium or low risk of infective endocarditis.
- Osteoporosis.
- Tobacco.
- Alcoholism.
- Bisphosphonates.
- Radiotherapy.
- Chemotherapy.
- Periodontal disease.
- Bruxism.
2.3. Exo oral examination
- Appearance and color of the integuments;
- Palpation of the ATM;
- Profile study;
- Face study;
- Smile Exam
In the face of anterior edentulism; a detailed aesthetic analysis of the smile is carried out in order to obtain the best aesthetic results.
- Endo-oral examination
- Dental check-up
- Dental formula
- CAD Index
- Condition of residual roots
- Quality of care and prosthetic achievements
2.5.2. Periodontal assessment
Allows you to evaluate:
• oral hygiene and gingival inflammation,
• The condition of the supporting tissues of the residual teeth,
• Loss of attachments
• The importance of alveolysis
According to Rooset coll; Individuals susceptible to periodontitis are more exposed to peri-implant destruction of infectious origin.
Note: periodontal treatment and restoration of the oral cavity (scaling, extraction of residual roots, etc.) are a priority before any implant treatment.
2.5.3. Mouth opening
In the posterior sector, implant surgery requires a normal opening of 4 to 6 cm;
An opening less than 4 cm represents an absolute contraindication to guided surgery. (Dada et al, 2011).
2.5.4 . Occlusal examination
The static and dynamic evaluation highlights:
- Angle classification,
- The occlusal plane,
- Lateral movements (group or canine function, premature contacts, etc.)
- In the anterior sector, the overlap, the overhang are measured and the propulsion which must be evaluated.
2.6. Radiological examination
- First-line examinations: ( dental panoramic, retroalveolar images, etc.)
Implant planning and prosthetic project
Goals:
- Perform a radiological periodontal assessment.
- Look for bone and cystic pathologies.
- Determine implant feasibility (anatomical limits and obstacles).
- X-rays (scanner, cone beam); allow obtaining the data necessary for radiological diagnosis and measuring distances in implantology with software .
Implant planning and prosthetic project
2.7. Identification of anatomical obstacles
Implant surgery requires a good knowledge of the anatomy of implantable sites and their limits (anatomical obstacles).
2.7.1. Atomic structures to be respected
2.7.2. Risks due to implant surgery
Renouard and Ranger (2008) classify anatomical risks in implant surgery into:
- Type I risks : damage to an anatomical structure with only one consequence: hemorrhage which will be stopped when the implant is placed.
- Type II risks : risk of non-osseointegration due to the presence of a lacunar structure.
- Type III risks : creation of a situation of temporary or permanent discomfort. This is essentially a lesion of the suborbital pedicle during the placement of zygomatic implants.
- Type IV risks: These risks correspond to the creation of disproportionate trauma with the placement of an implant.
2.7.3 . Anatomical variations due to edentulism
In the maxilla, resorption is centripetal, unlike in the mandible; maxillomandibular relationships can therefore be reversed.
These changes have many implications for surgical technique, inclination and choice of implants.
3. Prosthetic planning
3.1. Study models and diagnostic waxes
The analysis of study models allows us to analyze:
-Occlusion
-Inter-arcade reports
-The available prosthetic space
-Interferences and prematurities
-Occlusal pathologies
The creation of a study model and diagnostic waxes will result in the creation of a model, then a temporary resin prosthesis and the radiological guide.
- Diagnostic wax (Wax up)
It is a wax assembly that represents the future
Prosthesis on implant at the level of the missing tooth;
Validation of the prosthesis will be after:
– the aesthetic fitting;
– Checking shape, height and position
ideal teeth;
– checking the occlusion.
3.2. The radiological guide
Made of transparent resin in which we drill
and a radiopaque material is introduced
(gutta-percha, zinc oxide cement, etc.);
an x-ray is taken with the guide in the mouth.
3.3. Bone analysis
3.3.1. Bone density assessment
Primary stability is a function of bone density according to the classification of
LEKHOLM AND ZARB (1985); This density is classified from D1 to D4 (D1 being the densest and D4 the least dense).
Must be appreciated because it has a direct influence on the treatment plan and the different drilling sequences.
Implant planning and prosthetic project
3.3.2. Osteointegration
In 1977, (Branemark et al) defined osseointegration as direct bone apposition on the implant surface. Osteointegration occurs in 2 phases:
- Primary stability:
Mechanical anchoring phase of the implant in the prepared site; Depends on:
- Bone quality
- Available bone volume
- Surgical technique
- Implant morphology
- Secondary stability:
Characterized by the formation of biological cohesion between the bone tissue and the implant;
In order to increase the chances of success it is necessary to:
– Minimize the stresses exerted on the implants
– Increase the number of implants
– Better distribution of implants
– Put in under occlusion
– Use implants with rough surfaces
– Direct the forces in the implant axis
– Solidify the implants
3.3.3. Choice of implants
Distances between implants
A minimum distance must be respected between the implants which will be 3 mm to have a bone crest summit favorable to obtaining a gingival papilla and 2 mm between an implant and a root.
Implant planning and prosthetic project
- Choice of axis:
The implant will be positioned in the palatal position or in the center of the crest to preserve the vestibular cortex which is very sensitive to significant resorption.
3.4. Implant planning software
The computer-assisted implantology system is considered as a chain allowing to place implants with a high level of precision.
Implant planning and prosthetic project
Benefits :
- Implant surgical simulation.
- Bone density measurement in the drilling area and in the periphery.
- Location of anatomical obstacles.
- Actual size print.
- Archiving.
- Teleradiography.
- Educational tool.
3.5. the surgical guide
Ozan et al (2009) define the surgical guide as the synthesis of the collected information necessary for good implant positioning for the selected concept.
It allows you to:
– Determines bone, mucosa and prosthetic emergence.
– Accurately determine the impact point of the implant, its inclination and its depth.
– Stabilizes the position of the drill bit during drilling, leaving it with very little freedom in its trajectory and depth.
• There are 3 types of surgical guides characterized by the base with which they are in contact:
- Bone-supported surgical guide:
- Surgical guide with mucosal support;
- Dental-supported surgical guide.
5. Planning of implant surgery
- The biological assessment (FNS. TP.TCK. Glycemia, etc.)
- Premedication (antibiotic, anti-inflammatory, analgesics)
- Determine the surgical protocol:
- Immediate or delayed implantation technique,
- Direct or flap technique,
- Post-operative follow-up Each step of implant planning is essential to ensure an optimal result.
Conclusion
Each step of implant planning is essential to ensure an optimal result.
Good communication with the patient and interdisciplinary collaboration (dentist, prosthetist) are also important for the success of any implant treatment.