00 µm).\ ECJ: E-cadherin junction, HGK: human gingival keratinocyte, FITC: fluorescein isothiocyanate-labeled, DAPI: 0′, 0-diamidino-0-phenylindole dihydrochloride, S: smooth culture dish, R(0000): prepared with \#0000 sandpaper, R(0000): prepared with \#0000 sandpaper, R(000): prepared with \#000 sandpaper.](jpis-00-000-g000){#F0}  