Comparative evaluation between alloplastic bone grafts in granules vs. paste in maxillary sinus surgeries: microtomographic analysis in rabbits

Abstract

The present experiment aims to analyze the repair of maxillary sinuses regarding incorporation, new formation and bone remodeling, after grafting two types of commercial formulations of an allopathic bone substitute in maxillary sinus lift surgeries in rabbits. In this prospective, randomized, split-mouth study, twenty male New Zealand rabbits, weighing around 3.5 - 4.0 kg and aged 5 - 6 months, will be divided into 2 groups of 10 rabbits each and submitted to the surgery in question. After lifting the sinus membrane, the same amount of granular bone substitute (Maxresorb®, Botiss Biomaterials, Zossen, Germany), which constitutes the control group, will be grafted to the elevated area; or in paste (Maxresorb® inject, Botiss Biomaterials, Zossen, Germany), representing the test group. The areas will be covered by a porcine collagen membrane (Bio-Gide®, Geistlich, Wolhusen, Switzerland). Each group of animals will be euthanized for 2 and 10 weeks respectively. The removed specimens will be sent for microtomographic analysis, and with the aid of the CTAn® software (Bruker, Kontich, Belgium) the following variables will be evaluated: total bone volume (BV = residual graft + new bone), number of trabeculae (Tb.N ), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp) and 3D reconstructions of the volumetric aspects in 2 and 10 weeks. The data obtained will be analyzed statistically through ANOVA analysis of variance (p <0.05) for intra and inter - group evaluation.