title: Human gingival fibroblast (HGF-1) attachment and proliferation on several abutment materials with various colors.
abstract: OBJECTIVE
  An implant abutment should be soft tissue-compatible and resistant to plaque accumulation, and it is preferable for an implant abutment to have color harmony with the surrounding tissues. This study aimed to compare the in vitro fibroblast cell attachment and proliferation on several abutment materials of different colors.
  
  
  METHODS
  A total of 240 specimens in 6 experimental groups were used: titanium alloy (SM [smooth machined]; gray), cobalt-chrome-molybdenum alloy (CCM; gray), titanium nitride-coated titanium (TiN; yellow), anodic-oxidized titanium (AO; dark pink), composite resin-coated titanium (R; white), and zirconia (Zr; white). The culture plate surface was employed as a control (C). The surface roughness (Sa), developed interfacial area ratio (Sdr), and water contact angle (WCA) were measured. The human gingival fibroblast (HGF-1) attachment and proliferation at the third and seventh days were observed.
  
  
  RESULTS
  Sa values of all experimental groups were < 0.5 μm. Sdr values were between 5% and 8%, except for the Zr group (0.06%). WCA of all groups was greater than 40 degrees. More HGF-1 cells attached on the surfaces of the SM, TiN, and Zr groups than the C group, and the least number of cells were observed on the CCM group (P < .001). On the third day of proliferation, the C group showed significantly greater proliferation than all experimental groups (P < .001). On the seventh day of proliferation, the TiN, AO, Zr, and C groups exhibited twice the number of cells compared to the rest of the groups (P < .001).
  
  
  CONCLUSIONS
  Within the limitations of this study, zirconia abutments would be the best choice in the anterior region. Titanium nitride-coated titanium alloy abutments or anodic-oxidized titanium alloy abutments might also be good choices in areas of esthetic challenge or under high occlusal loads.
authors.forename: Young-Sung
authors.initials: YS
authors.lastname: Kim
authors.forename: Youngkyung
authors.initials: Y
authors.lastname: Ko
authors.forename: Seung-Beom
authors.initials: SB
authors.lastname: Kye
authors.forename: Seung-Min
authors.initials: SM
authors.lastname: Yang
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D003116:Color; D003188:Composite Resins; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D019232:Dental Restoration Failure; D005347:Fibroblasts / Q000502:physiology*; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D013499:Surface Properties; D014025:Titanium; D017155:Wettability; D015040:Zirconium
chemical_list: D003188:Composite Resins; C041500:titanium nitride; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide