Osteoconductive Properties of a Volume-Stable Collagen Matrix in Rat Calvaria Defects: A Pilot Study
Karol Alí Apaza Alccayhuaman,
Stefan Tangl,
Stéphane Blouin,
Markus A. Hartmann,
Patrick Heimel,
Ulrike Kuchler,
Jung-Seok Lee,
Reinhard Gruber
Affiliations
Karol Alí Apaza Alccayhuaman
Department of Oral Biology, Dental School, Medical University of Vienna, Sensengasse 2a, 1090 Vienna, Austria
Stefan Tangl
Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, School of Dentistry, Medical University of Vienna, 1090 Vienna, Austria
Stéphane Blouin
1st Medical Department, Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, Hanusch Hospital, 1140 Vienna, Austria
Markus A. Hartmann
1st Medical Department, Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, Hanusch Hospital, 1140 Vienna, Austria
Patrick Heimel
Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, School of Dentistry, Medical University of Vienna, 1090 Vienna, Austria
Ulrike Kuchler
Department of Oral Surgery, Medical University of Vienna, 1090 Vienna, Austria
Jung-Seok Lee
Department of Oral Biology, Dental School, Medical University of Vienna, Sensengasse 2a, 1090 Vienna, Austria
Reinhard Gruber
Department of Oral Biology, Dental School, Medical University of Vienna, Sensengasse 2a, 1090 Vienna, Austria
Volume-stable collagen matrices (VSCM) are conductive for the connective tissue upon soft tissue augmentation. Considering that collagen has osteoconductive properties, we have investigated the possibility that the VSCM also consolidates with the newly formed bone. To this end, we covered nine rat calvaria circular defects with a VSCM. After four weeks, histology, histomorphometry, quantitative backscattered electron imaging, and microcomputed tomography were performed. We report that the overall pattern of mineralization inside the VSCM was heterogeneous. Histology revealed, apart from the characteristic woven bone formation, areas of round-shaped hypertrophic chondrocyte-like cells surrounded by a mineralized extracellular matrix. Quantitative backscattered electron imaging confirmed the heterogenous mineralization occurring within the VSCM. Histomorphometry found new bone to be 0.7 mm2 (0.01 min; 2.4 max), similar to the chondrogenic mineralized extracellular matrix with 0.7 mm2 (0.0 min; 4.2 max). Microcomputed tomography showed the overall mineralized tissue in the defect to be 1.6 mm3 (min 0.0; max 13.3). These findings suggest that in a rat cranial defect, VSCM has a limited and heterogeneous capacity to support intramembranous bone formation but may allow the formation of bone via the endochondral route.