title: Comparison of alkaline phosphatase activity of MC3T3-E1 cells cultured on different Ti surfaces: modified sandblasted with large grit and acid-etched (MSLA), laser-treated, and laser and acid-treated Ti surfaces.
abstract: OBJECTIVE
  In this study, the aim of this study was to evaluate the effect of implant surface treatment on cell differentiation of osteoblast cells. For this purpose, three surfaces were compared: (1) a modified SLA (MSLA: sand-blasted with large grit, acid-etched, and immersed in 0.9% NaCl), (2) a laser treatment (LT: laser treatment) titanium surface and (3) a laser and acid-treated (LAT: laser treatment, acid-etched) titanium surface.
  
  
  METHODS
  The MSLA surfaces were considered as the control group, and LT and LAT surfaces as test groups. Alkaline phosphatase expression (ALP) was used to quantify osteoblastic differentiation of MC3T3-E1 cell. Surface roughness was evaluated by a contact profilometer (URFPAK-SV; Mitutoyo, Kawasaki, Japan) and characterized by two parameters: mean roughness (Ra) and maximum peak-to-valley height (Rt).
  
  
  RESULTS
  Scanning electron microscope revealed that MSLA (control group) surface was not as rough as LT, LAT surface (test groups). Alkaline phosphatase expression, the measure of osteoblastic differentiation, and total ALP expression by surface-adherent cells were found to be highest at 21 days for all three surfaces tested (P<.05). Furthermore, ALP expression levels of MSLA and LAT surfaces were significantly higher than expression levels of LT surface-adherent cells at 7, 14, and 21 days, respectively (P<.05). However, ALP expression levels between MSLA and LAT surface were equal at 7, 14, and 21 days (P>.05).
  
  
  CONCLUSIONS
  This study suggested that MSLA and LAT surfaces exhibited more favorable environment for osteoblast differentiation when compared with LT surface, the results that are important for implant surface modification studies.
authors.affiliation: Department of Prosthodontics, College of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Lin-Jie
authors.initials: LJ
authors.lastname: Li
authors.affiliation: CSM IMPLANT Surface Treatment Institute, Daegu, Republic of Korea.
authors.forename: So-Nam
authors.initials: SN
authors.lastname: Kim
authors.affiliation: Department of Prosthodontics, College of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Sung-Am
authors.identifier: 0000-0002-8315-7833
authors.initials: SA
authors.lastname: Cho
keywords: ALP activity; Laser and acid-treated surface; MC3T3-E1; Modified SLA; Roughness