The geometry of the implant and its relationship with occlusal forces

 

 

The success of implant therapy and bone loss is related to different design of the implant body. Macroscopic design of an implant has a great impact on force bearing surface in the bone. Protruding parts from implant surface such as ridge, bone crest, threads can transfer stresses to the bone while forcing.

 

The results of a study of tooth implants with the subject of square threads showed that when the implant slots are filled up completely with bone, more bone mass will be present in the lower part of the thread in comparison to the upper area of it. In addition, presence of a bone bridge between a square thread to the other is seen. It is for creating a better bone contact surface on the floor of square thread to bear more pressure on the bone.

Any form of thread is designed in such a way to increase the compressive forces exerted on the implant surface and to decrease shear forces.

After primary repair, bone density is distributed equally in upper and lower part of the grooved implant.

However, after dynamic loading, bone density of the implant will be more in lower part of the face angle and will be less in upper part of the groove.

 

 

Due to lateral force, strain will be more focused on the tip of the thread. This value is reducing from external to internal areas of the thread.

Since the strain is at most in the tip of the implant thread, bone will dwindled but strain is reduced at the depth of the thread and the bone is preserved.

Bone contact is at least at the tip of the implant thread (while the strain is greatest in this area) and is at most in thread face angle (where the bones are under great pressures). So, implant design is not only for supplying primary stability but for creating BIC (Bone Implant Contact) and also it is needed for effective transfer of forces to the bone