One of the most important and obvious differences between implants and teeth is the lack of the Periodontal Ligament (PDL). The PDL contains mechanoreceptors that help determine the amount of force being applied to a tooth. This helps act as a safety mechanism for the tooth, so that it is not overloaded with stress.
Teeth can adapt to occlusal forces, implants cannot.
Implants do not have a PDL and are intimately integrated to bone preventing them to adapt to occlusal forces like the natural dentition. Therefore, the health of the surrounding bone and soft tissue is more dependent on the occlusal forces that an implant is subjected to. One must also remember the lack of adaptability when opening vertical on patients. Careful planning and time management is critical in these cases when implants are involved.
These forces can result in breakdown of the prosthetic.
Not only will these forces take a toll on the peridontium, but they can also be destructive to our prosthetics as well. More commonly, we see screw loosing and fractures of implant prosthetics which can be directly related to our occlusal schemes. Therefore, implant placement MUST be initially planned with a prosthetic eye and the end goal in sight. We know that bone is at its strongest in its compressive state, as opposed to weakest in its sheer state or lateral forces. Planning from a prosthetic background will help to ensure that these forces are properly directed down the long axis of the implant.
Minimize forces on single tooth implants and keep the end in mind.
Our prosthetic design for single tooth implant restorations should be carefully considered. Unlike natural tooth crowns, a smaller occlusal table is more ideal. Try and provide a wider occlusal fossa that allows for a light centric stop along with shallow cusp heights that helps ensure absolutely no excursive interferences. This design will help minimize unfavorable cantilever forces that produce undesirable lateral stress on surrounding bone. The concept of implant placement in relation to occlusion can be complex, however, If you stick to the fundamental criteria by Carl Misch and the foundations of a stable occlusion by Dr. Dawson – you cant go wrong.