Microtomographic reconstruction of mandibular defects treated with xenografts and collagen-based membranes: A pre-clinical minipig model / Reconstrucción microtomográfica de defectos mandibulares tratados con Xenoinjertos y membranas a base de colágeno: un modelo preclínico de minicerdo

ABSTRACT

Background: The goal of this study was to evaluate hard tissue response following guided bone regeneration us-ing commercially available bovine bone grafts and collagen membranes; bilayer collagen membrane and porcinepericardium-based membrane, by means of a non-destructive three-dimensional (3D) computerized volumetricanalysis following microtomography reconstruction.Material and Methods: Bone regenerative properties of various bovine bone graft materials were evaluated in theGöttingen minipig model. Two standardized intraosseous defects (15mm x 8mm x 8mm) were created bilaterallyof the mandible of eighteen animals (n=72 defects). Groups were nested within the same subject and randomlydistributed among the sites (i) negative control (no graft and membrane), (ii) bovine bone graft/bilayer collagenmembrane (BOB) (iii) Bio-Oss® bone graft/porcine pericardium-based membrane (BOJ) and (iv) cerabone® bonegraft/porcine pericardium-based membrane (CJ). Samples were harvested at 4, 8, and 12-week time points (n=6animal/time point). Segments were scanned using computerized microtomography (μCT) and three dimensionallyreconstructed utilizing volumetric reconstruction software. Statistical analyses were performed using IBM SPSSwith a significance level of 5% Results: From a temporal perspective, tridimensional evaluation revealed gradual bone ingrowth with the presenceof particulate bone grafts bridging the defect walls, and mandibular architecture preservation over time. Volumetricanalysis demonstrated no significant difference between all groups at 4 weeks (p>0.127). At 8 and 12 weeks therewas a higher percentage of new bone formation for control and CJ groups when compared to BOB and BOJ groups(p<0.039). The natural bovine bone graft group showed more potential for graft resorption over time relative to bo-vine bone graft, significantly different between 4 and 8 weeks (p<0.003)...(AU)