Proliferation of mouse fibroblast-like and osteoblast-like cells on pure titanium films manufactured by electron beam melting.

The physical characteristics and biological compatibility of surfaces produced by electron beam melting (EBM) are not well known. In particular, there are not many reports on biocompatibility qualities. In this study, pure Ti films were manufactured using EBM. While it is reported that moderately hydrophilic biomaterial surfaces display improved cell growth and biocompatibility, contact angle measurements on the EBM-produced pure Ti films showed slight hydrophobicity. Nonetheless, we found the cell count of both fibroblast-like cells (L929) and osteoblast-like cells (MC3T3-E1) increased on pure Ti films, especially the MC3T3-E1, which increased more than that of the control. In addition, the morphology of L929 and MC3T3-E1 was polygonal and spindle-shaped and the cytoskeleton was well developed in the pure Ti surface groups. Upon staining with Alizarin red S, a slight calcium deposition was observed and this level gradually rose to a remarkable level. These results indicate that pure Ti films manufactured by EBM have good biocompatibility and could be widely applied as biomedical materials in the near future.

Antimicrobial efficacy of gutta-percha supplemented with cetylpyridinium chloride.

To develop a root canal filling material with high antimicrobial activity, we prepared gutta-percha supplemented with the cationic surfactant cetylpyridinium chloride (CPC). Thermoplastic gutta-percha was supplemented with 0.05%, 0.2%, or 0.8% CPC. The gutta-percha containing CPC was tightly packed at the bottom of a 24-well plate. Its antimicrobial activity against eight representative endodontic pathogens-including gram-positive and gram-negative bacteria and fungi-was evaluated by adding 0.5 mL of liquid samples containing pathogens to the wells. After 24 h of cultivation under appropriate conditions, microbial growth was analyzed by counting colony-forming units (CFU). Gutta-percha alone (without CPC) partially inhibited microbial growth, probably through the antimicrobial effect of some of its components, such as zinc oxide. Addition of CPC dose-dependently increased the antimicrobial efficacy of gutta-percha. Addition of 0.05%, 0.2%, and 0.8% CPC reduced the viable microbial number to below the lower limit of detection (20 CFU/mL) for all tested pathogens except Pseudomonas aeruginosa, which was detected in 0.8% CPC-containing gutta-percha, although the viable number significantly decreased. Gutta-percha with CPC might be useful for preventing microbial infections during root canal therapy. (J Oral Sci 58, 277-282, 2016).