Photofunctionalization Enhances Osteoconductivity of Medical Titanium Mesh

Hirota, Makoto

Photofunctionalization Enhances Osteoconductivity of Medical Titanium Mesh

Thursday, October 10, 2013

Makoto Hirota DDS, PhD, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Takayuki Ikeda DDS, PhD, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Masako Tabuchi DDS, PhD, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Kahori Nakagawa DDS, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Rajita Kanuru DDS, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Takahiro Ogawa DDS, PhD, Laboratory for Bone and Implant Sciences, Advanced prosthodontics, Weintraub center for reconstructive biotechnology, University of California - Los Angeles, School of Dentistry, Los Angeles, CA

Objective: Guided bone surgery using thin titanium materials, e.g., titanium mesh, faces many challenges. Bone augmentation surgery using titanium mesh is sometimes insufficient. Ultra Violet (UV)-mediated photofunctionalization has earned a considerable attention to enhance biological capability of dental implants. It is unknown, however, whether and how photofunctionalization is effective in enhancing titanium materials with machined, smooth surfaces as well as with structural discontinuity like mesh structures. This study examined the effects of UV treatment on titanium mesh materials in vitro and in vivo.

Method: Titanium mesh products were autoclaved and stored under dark ambient conditions for 4 weeks. UV treatment was performed by a combination of UVA and UVC for 15 min. Bone marrow derived osteoblast abilities, such as cell attachment, proliferation, ALP activity and mineralization were examined on titanium mesh with or without UV treatment. Osteoconductivity of titanium meshes was examined using scanning electron microscope and micro computed tomography in a rat femur model. The titanium mesh implanted into the rat femur bone and evaluated 2 and 3 weeks after surgery. For the comparison between UV-treated and untreated group, student t-test was used and P < 0.05 was considered statistically significant.

Results: The amount of osteoblasts attached to UV-treated mesh at 3 and 24 hours of incubation was significantly greater than that to untreated mesh. The BrdU incorporation on UV-treated meshes was significantly greater at day 2. The ALP activity significantly increased 2 times on UV-treated mesh at days 5 and 10. The mineralization significantly increased 1.5 times on UV-treated mesh at day 10. The coverage of new bone on the material surfaces as well as the percentage of bone occupation in the hole area significantly increased 100% by UV treatment.

Conclusion: The results from in vitro and in vivo studies collectively demonstrated that UV photofunctionalization of titanium mesh is effective in enhancing its osteoconductivity, which resulted in the increased bone formation not just on their surfaces but also hole areas of the material.

References:

Aita H, Hori N, et al: The effect of ultraviolet funcitionalization of titanium on integration with bone. Biomaterials 30: 1015-1025, 2009.

Att W, Ogawa T: Biological aging of implant surface and their restoration with ultraviolet light treatment: a novel understanding of osseointegration. International Journal of Oral and Maxillofaical Implants 27: 753-761, 2012.