Effect of pulsed electromagnetic field on implants osseointegration: study histomorfometric in rats

Abstract

Osseointegrated implant therapy is an effective clinical approach with high success rates dependent on the osseointegration process. With the need for less time rehabilitation and long term success, the application of the pulsed electromagnetic field (PEMF) in osseointegration has been the object of studies. This is a noninvasive therapy that presents many positive aspects in the effective formation and quantity of bone in contact with the surface of the implant in a shorter time, increase in the degree of mineralization and bone maturation. There was also an increase in the initial adhesion, proliferation and differentiation of osteoblasts and the gene expression associated with osteogenesis. However, it is also noted that this therapy did not result in a significant improvement of the osseointegration and healing process. With this, we question the use of protocols involving different parameters of the electromagnetic field in the available results. Thus, it is still important to verify the possibility of a protocol that addresses, from fixed parameters of the PEMF, ideal duration for the optimization of osseointegration. For this, 60 animals (Rattus norvegicus, variant albinus, Wistar) will be used, randomly divided into 3 groups: Control Group, only the implant in the left tíbia; GTA Group, implant in the left tibia and exposure to 3h of PEMF; and the GTB Group, implant in the left tibia and exposure to 1h PEMF. In each of the groups, the animals will be subdivided into 4 subgroups according to the euthanasia periods of 03, 07, 21 and 45 days. The pieces will be separated and prepared without decalcification for the histomorphometric analysis that will be performed through the Image J software (NIH Image J 1.34) of the parameters: - Linear extension of the bone tissue in contact with the coils of the implant (bone implant contact-BIC); % of area between spines occupied by bone tissue (bone area fraction occupied - BAFO); - Bone cortical thickness.Data will be tabulated and appropriate statistical tests applied, with a significance level of 5%.