Biomechanical properties of jaw periosteum-derived mineralized culture on different titanium topography.
OBJECTIVE
This study evaluated the biomechanical properties of periosteum-derived mineralized culture on different surface topographies of titanium.


METHODS
Titanium surfaces modified by machining or by acid etching were analyzed using scanning electron microscopy (SEM). Rat mandibular periosteum-derived cells were cultured on either of the titanium surfaces. Cell proliferation was evaluated by cell counts, and gene expression was analyzed using a reverse-transcriptase polymerase chain reaction. Alkaline phosphatase (ALP) stain assay was employed to evaluate osteoblastic activity. Matrix mineralization was examined via von Kossa stain assay, total calcium deposition, and SEM. The hardness and elastic modulus of mineralized cultures were measured using a nano-indenter.


RESULTS
The machined surface demonstrated a flat topographic configuration, while the acid-etched surface revealed a uniform micron-scale roughness. Both cell density and ALP activity were significantly higher on the machined surface than on the acid-etched surface. The expression of bone-related genes was up-regulated or enhanced on the acid-etched surface compared to the machined surface. Von Kossa stain showed significantly greater positive areas for the machined surface compared to the acid-etched surface, while total calcium deposition was statistically similar. Mineralized culture on the acid-etched surface was characterized by denser calcium deposition, more mature collagen deposition on the superficial layer, and larger and denser globular matrices inside the matrix than the culture on the machined surface. The mineralized matrix on the acid-etched surface was two times harder than on the machined surface, whereas the elastic modulus was comparable between the two surfaces.


CONCLUSIONS
The design of this study can be used as a model to evaluate the effect of implant surface topography on the biomechanical properties of periosteum-derived mineralized culture. The results suggest that mandibular periosteal cells respond to different titanium surface topographies differently enough to produce mineralized matrices with different biomechanical qualities.
Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, School of Dentistry, University of California at Los Angeles, USA. wael.att@uniklinik-freiburg.de
Wael
W
Att
Katsutoshi
K
Kubo
Masahiro
M
Yamada
Hatsuhiko
H
Maeda
Takahiro
T
Ogawa
D000134:Acid Etching, Dental / Q000379:methods; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001696:Biomechanical Phenomena; D002113:Calcification, Physiologic / Q000502:physiology*; D002118:Calcium / Q000032:analysis; D002452:Cell Count; D049109:Cell Proliferation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000032:analysis; D003764:Dental Materials / Q000737:chemistry*; D055119:Elastic Modulus; D006244:Hardness; D008334:Mandible / Q000166:cytology* / Q000502:physiology; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D010006:Osteoblasts / Q000502:physiology; D015675:Osteocalcin / Q000032:analysis; D053495:Osteopontin / Q000032:analysis; D010521:Periosteum / Q000166:cytology* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
D015415:Biomarkers; D024042:Collagen Type I; D003764:Dental Materials; C506897:Spp1 protein, rat; D015675:Osteocalcin; D053495:Osteopontin; D014025:Titanium; D000469:Alkaline Phosphatase; D002118:Calcium