Dental implants. The treatment plan
Planning for dental implants is probably the most important step of the entire treatment. Depending on the case complexity, a various number of practitioners may be involved in this particular stage.
- Oral surgeon - the doctor who will place the implants inside the jawbone and perform other additional surgical procedures
- Prosthodontist - the physician in charge of the prosthetic phase and the general planning for a particular type of prosthesis
- Gnatologyst - in complex cases, this medical specialist will create a functional occlusion in order to distribute the chewing forces evenly across the prosthetics the implants support
- Dental technician - usually with a specific training in the field
- Physicians of other specialities
Obviously, in less complex cases, one or two practitioners can perform all the operations described above. Modern computer software is also available for highly accurate planning.
3D dental implant computer planning
An accurate treatment plan will have a positive impact on the success rate of the implant fixtures and the lifespan of the prosthetic device.
When the treatment plan is designed, all the important issues will have to be considered :
- the data obtained from the medical history and the physical examination
- the information gathered from the dental X-rays, CT scan and other imaging methods
- patient preferences for a particular prosthetics ; for example, some people prefer to have fixed (permanent) crown and bridgework instead of removable ones
- patient financial situation and time available ; sometimes, patients cannot afford a particular solution
- other factors can be involved depending on the clinical situation, geographic area, practitioner preferences etc
When the treatment plan is devised, all surgical and prosthetic procedures are clearly established.
a. General considerations
Some serious general health conditions absolutely preclude placing implants. Other situations are evaluated on a case-by-case basis. Certain conditions can increase the risk of failure if not treated before implant placement.
b. The treatment of all existing conditions
It is essential that before any surgical procedures, all structures inside the mouth cavity are healthy or properly treated. Otherwise, there is a great risk of failure.
- The treatment of teeth decays
- The treatment of gingivitis, periodontal disease and any other soft tissue conditions
- Endodontic therapy for the teeth with chronic infections
- Professional dental cleaning and the removal of dental tartar (scaling)
- The teeth that can no longer be treated are extracted
These operations should be completed before any surgery takes place.
c. Selecting the type of implant supported prosthesis
The final prosthetic can be either fixed, where a person cannot remove the denture or teeth from their mouth or removable, where they can remove the prosthetic.
Where the prosthetic is fixed, the crown, bridge or denture is fixed to the abutments with either lag-screws or cement. Where the prosthetic is removable, a corresponding adapter is placed in the prosthetic so that the two pieces can be secured together.
implant supported crown
implant supported bridge
removable denture supported by implants
fixed denture supported by implants
d. Selecting the number of implants and the type and position of each dental implant
Planning the position and number of implants is key to the long-term health of the prosthetic since biomechanical forces created during chewing can be significant.
The number of implants directly depends on the type of prosthetic restoration. Normally, a removable denture needs fewer supporting implants than a fixed denture (although this is not a general rule).
removable denture can be supported
by only 2 implants
a fixed denture needs
more supporting implants
Dental implants have no periodontal ligament, hence there is no sensation of pressure when biting so the forces created are higher.
To offset this, the location of implants must distribute forces evenly across the prosthetics they support. Concentrated forces can result in fracture of the bridgework, implant components, or loss of bone adjacent the implants.
The ultimate location of implants is based on both biologic (bone type, vital structures, health) and mechanical factors. Implants placed in thicker, stronger bone ( e.g. the front part of the bottom jaw) have lower failure rates than implants placed in lower density bone (such as the back part of the upper jaw).
When a more exacting plan is needed, the dentist can make an acrylic or plastic guide called guidance stent. The guidance stent is manufactured prior to surgery and guides optimal positioning of the implants.
guidance stent during surgery
The stent can be made following computerized planning of a case from the CT scan.
Dental implants and abutments come in a wide range of sizes and shapes. The practitioner will select the implants and the abutments that best fit the clinical application.
dental implants of various sizes
implant abutments of various types
Most often, larger implants (and artificial abutments) are selected for the back part of the mouth due to the increased chewing forces (although this is not a general rule).
The length and diameter of dental implants ultimately depends on the bone structure and the type of prosthesis that is planned.
e. Planning the adjunctive surgical procedures
It is not uncommon that the size and/or structure of the bone is not adequate to support the designed implants. In this case, adjunctive surgical procedures are planned to increase the amount of bone (e.g bone graft, sinus lift).
Other procedures aim to recreate the soft tissues that surround the implants or to reposition anatomical structures that might interfere with the dental implants (e.g soft tissue reconstruction, alveolar nerve repositioning, sinus lift).
Depending on the clinical conditions, these procedures are performed either before (more often) the base procedure or during implant placement.
At the end, every procedure is precisely scheduled and all the important details are clarified.
Last review and update: February 2019