Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts

Purpose: The objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti. Materials and methods: Forty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-μm dimples at 10-μm intervals, and SM30 (n=16) had 5-μm dimples at 25-μm intervals in a 2 × 4 mm² area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences. Results: The adhesion strength of epithelial cells was higher on Ti surfaces with 5-μm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins. Conclusion: These findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment.