Oral implant osseointegration model in C57Bl/6 mice: microtomographic, histological, histomorphometric and molecular characterization

Abstract

Despite the successful clinical application of titanium (Ti) as a biomaterial, the exact cellular and molecular mechanisms responsible for Ti osseointegration remains unclear, especially because of the limited methodological tools available in this field.Objective:In this study, we present a microscopic and molecular characterization of an oral implant osseointegration model using C57Bl/6 mice.Material and Methods:Forty-eight male wild-type mice received a Ti implant on the edentulous alveolar crest and the peri-implant sites were evaluated through microscopic (μCT, histological and birefringence) and molecular (RealTimePCRarray) analysis in different points in time after surgery (3, 7, 14 and 21 days).Results:The early stages of osseointegration were marked by an increased expression of growth factors and MSC markers. Subsequently, a provisional granulation tissue was formed, with high expression of VEGFb and earlier osteogenic markers (BMPs, ALP and Runx2). The immune/inflammatory phase was evidenced by an increased density of inflammatory cells, and high expression of cytokines (TNF, IL6, IL1) chemokines (CXCL3, CCL2, CCL5 and CXC3CL1) and chemokine receptors (CCR2 and CCR5). Also, iNOS expression remained low, while ARG1 was upregulated, indicating predominance of a M2-type response. At later points in time, the bone matrix density and volume were increased, in agreement with a high expression of Col1a1 and Col21a2. The remodelling process was marked by peaks of MMPs, RANKL and OPG expression at 14 days, and an increased density of osteoclasts. At 21 days, intimate Ti/bone contact was observed, with expression of final osteoblast differentiation markers (PHEX, SOST), as well as red spectrum collagen fibers.Conclusions:This study demonstrated a unique molecular view of oral osseointegration kinetics in C57Bl/6 mice, evidencing potential elements responsible for orchestrating cell migration, proliferation, ECM deposition and maturation, angiogenesis, bone formation and remodeling at the bone-implant interface in parallel with a novel microscopic analysis.

Coupling between Osseointegration and Mechanotransduction to Maintain Foreign Body Equilibrium in the Long-Term: A Comprehensive Overview

“…Recent studies on osseointegrated titanium oral implants demonstrate the presence of the M2 phenotype of the macrophage from the early stage of healing (days) [4,10,45,53]. However, the presence of other chemical elements on the surface of the titanium implant seems to be relevant for the bone balance of osseointegration [2].…”

Medication-related osteonecrosis of the jaws after tooth extraction in senescent female mice treated with zoledronic acid: microtomographic, histological and immunohistochemical characterization

“…Mice are considered a reliable in vivo system for immunological investigations and have conferred multiple advantages over other animal models therein [20]. Namely, the small size of the animal requires reduced amount of the drug, rapid cumulative effects due to rapid mice metabolism, and the possibility of using genetically-manipulated animals to determine a cause-and-effect relationship between the target disruption of a gene and its function [21][22][23]. Several MRONJ models have been developed using mainly C57BL/6 and other mice strains (S1 Table), [15,17,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39].…”

Is maxillary diastema an appropriate site for implantation in rats?

“…Some investigators placed implant out of oral cavity such as the femur [9] and the tibia [12], or not on the ridge of the alveolar bone, i.e., the ramus of mandibular [14] to achieve osseointegration which are able to have samples for osseointegration; however, these models are not closely relevant to clinical implant placement. Implantation at diastema has been reported in mice [30]. However, the pictures showed in the articles, large portion of the implant (0.6 mm × 1.5 mm) are clear projected into the maxillary sinus though some peri-implant bone was observed by the authors.…”