Study of the bone healing process around implants placed in the maxillary sinus with surface modified by dual acid etched followed by deposition of ²-tricalcium phosphate: biomechanics, histometric and tomographic evaluation

Abstract

Study of the repair process around implants placed in maxillary sinus with surface modified by acid etched with and without ²-tricalcium phosphate deposition. Evaluation biomechanical, histometric and micro-tomography. Physico-chemical modifications on the surfaces of the titanium implants can be performed in order to increase the capacity of new bone formation around the implants threads to achieve better levels of osseointegration. The objective of this study will be to evaluate the effects of ²-tricalcium phosphate coating on the surface of acid-modified implants placed in maxillary sinuses of rabbits immediately after sinus elevation. For this 18 New Zealand (Albinus) rabbits will be submitted bilateral sinus membrane elevation surgery by nasal access. After the animals will receive randomly one implant in each maxillary sinus with surface modified by acid conditioning followed by deposition of SBF or surface modified by acid conditioning followed by deposition of SBF and ²-tricalcium phosphate. In the surgical procedure of implantation of the implants the primary stability coefficient will be measured by means of resonance frequency measurements in ISQ of all implants. After periods of 7, 15 and 40 days the animals will be anesthetized and in vivo the primary stability coefficient in ISQ will be measured, followed by euthanasia of the animals. Follow that the processing will be carried out to obtain paraffin cuts that will be stained with hematoxylin and eosin. Histometric analysis will be carried out to measure the bone interface contact and newly formed mineralized bone tissue. In addition, two animals from each group will be subjected to micro tomographic analysis to evaluate the volume and density of newly formed bone. The values obtained biomechanics and histometric analysis will be submitted to statistical analysis. (AU)