Dental Implants: Fit, Maintenance, and Placement

Fit of the Implant and the Frame

Pathogenic forces can act on the implant when the frame does not fit passively. In the case of a hybrid prosthesis, adjusting all retaining screws to close the gaps between the pillars and the teeth—giving the appearance of a proper fit—applies forces that can derail the implant. This setting can be assessed when only one screw is placed. If manufacturing has been carried out with CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing), the fit is better because the frame fits passively; this is superior to fits achieved with pillars made using standard technology.

Maintenance

The objective of implant maintenance is the reduction of the mycobacterial population. Until more research is available, hygienic measures are crucial to prolong the life of the implant. The practitioner should ensure proper patient training on techniques, as transmitted by the dentist and hygienist. Revisions should assess implant mobility and examine the area after placing the probes.

Anterior Mandible

Treatment planning for the anterior of the mandible tends to be less complicated. Usually, the height and width are appropriate for implant placement, and bone quality is typically excellent. Experienced clinicians have demonstrated success with immediate loading of implants in the posterior mandible. (Loading). The implant should be placed through the spongy bone to cover the cortex of the lower mandibular border. In the premolar area, careful attention is needed to avoid affecting the mandibular nerve.

Posterior Mandible

The inferior alveolar nerve runs through the mandibular body in this area. If not taken into account, nerve damage can occur. Implants placed in this area tend to be shorter, without cortical bone covering the lower part, and are exposed to higher occlusal forces once placed. Consequently, more time should be allowed for integration. If shorter implants are used, more implants are recommended to withstand occlusal forces.

Biomechanical Factors Affecting Long-Term Implant Success

Occlusion is important. Bone resorption may be due to premature or repeated loading. Vertical or angular bone loss is usually characteristic of occlusal trauma-induced bone resorption. When this concentrated pressure occurs, osteoclast bone resorption activity is triggered. In natural dentition, bone remodeling usually occurs when the severe concentration of stress is reduced or eliminated. With osseointegrated implant systems, after bone is resorbed, it does not usually return to its original form. Lateral forces on the implants should be minimized because implants resist forces more effectively along their longest axis.

Union of Natural Tooth and Implant

It has been suggested that uniting an osseointegrated implant to a natural tooth with a fixed dental prosthesis can create excessive forces due to the functional mobility of natural teeth. It is preferable for a fixed implant denture to have two or more implants. If anatomical limitations prevent this, using more natural tooth abutments is an option. Another option is an attachment in the prosthesis between the implant and natural tooth to mitigate any problems.