Osteoprogenitor Cellular Response to Silicon-Based Anodic Spark Deposition Titanium Surface

Introduction: Surface Modification of Titanium (Ti) implants has generated much attention in the research field of dental implantology, aiming at increasing the osteoconductivity of implant materials. We have recently modified an anodic spark deposition (ASD), electrochemical treatment technique, to obtain a thickened Ti oxide layer doped with calcium (Ca), phosphorous (P), and silicon (Si). Objectives: To evaluate the biological response to this novel Si-based treated Ti surface. Biological activity was assessed using two human cell models; primary human osteoblast (HOB), and human mesenchymal stem cells (MSCs). Methods: Three different Ti surfaces were investigated: ASD with Si based (ASDSi), conventional ASD (BioSpark™, BS), and chemically etched surface (BiRough™, BR). Commercially pure Ti (cpTi) was the non-treated control surface. All samples were cut into discs and sterilized by γ-irradiation prior to the test. Each surface was scanned using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and atomic force microscopy (AFM) for topographic and physicochemical characterization. HOB cells and MSCs were cultured in complete medium and seeded with the cell density of 1 x 10⁵ cell/ml, directly onto the test discs (ASDSi, BS, BR, and cpTi), as well as, Thermanox^® as a negative control (non-toxic material), and polyvinylchloride (PVC), as a positive control (toxic material). They were incubated at 37^oC and 5% CO₂. Cells were fixed and processed for SEM to assess morphology, and cell proliferation was determined using the alamarBlue™ and total DNA assay. Results: SEM images showed abundant cell layers on all surfaces with active cell visible, and cell filopodia extending across surface. All test samples showed comparable proliferation for both cell types compared to the controls. Conclusion: This study has demonstrated that the novel modified Ti surface had a nano-topographic texture, and chemical composition, favoring cell attachment and growing. This property would be beneficial in assisting fasten osseointegration.