title: In vivo investigation on connective tissue healing to polished surfaces with different surface wettability.
abstract: OBJECTIVE
  Connective tissue in contact to transgingival/-dermal implants presents itself as tight scar formation. Although rough surfaces support the attachment they increase bacterial colonisation as well. In contrast to surface roughness, little is known about the influence of surface wettability on soft-tissue healing in vivo. We therefore investigated the influence of different surface wettabilities on connective tissue healing at polished implant surfaces in vivo.
  
  
  METHODS
  Three polished experimental groups (titanium, titanium coated with hydrophobic nano-crystalline diamond (H-NCD) and titanium coated with hydrophilic nano-crystalline diamond (O-NCD) were inserted into the subcutaneous connective tissue of the abdominal wall of 24 rats. Animals were sacrificed after 1 and 4 weeks resulting in eight specimen per group per time point. Specimen were subjected to histological evaluation (van Giesson's staining) and immunohistochemistry staining for proliferating cell nuclear antigen (PCNA), fibronectin and tumour necrosis factor-alpha (TNF-α).
  
  
  RESULTS
  Histological evaluation revealed dense scar formation at the titanium and H-NCD surfaces. In contrast, the connective tissue was loose at the O-NCD surface with a significantly higher number of cells after 4 weeks. O-NCD demonstrated a strong expression of PCNA and fibronectin but a weak expression of TNF-α. In contrast, the PCNA and fibronectin expression was low at the titanium and H-NCD, with a strong signal of TNF-α at the H-NCD surface.
  
  
  CONCLUSIONS
  Hydrophilicity influences the connective tissue healing at polished implant surfaces in vivo positively. The attachment of connective tissue and the number of cells in contact to the surface were increased. Moreover, the inflammatory response is decreased at the hydrophilic surface.
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Kloss
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Doris
authors.initials: D
authors.lastname: Steinmüller-Nethl
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Stigler
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ennemoser
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Rasse
authors.affiliation: Department for Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austriarho-BeSt Coating GmbH, Innsbruck, Austria.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hächl
mesh_terms: D000818:Animals; D002921:Cicatrix; D020099:Coated Materials, Biocompatible; D003238:Connective Tissue / Q000601:surgery*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003775:Dental Polishing; D004846:Epithelial Attachment / Q000502:physiology*; D007150:Immunohistochemistry; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D014025:Titanium / Q000737:chemistry; D017155:Wettability; D014945:Wound Healing / Q000502:physiology*
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D014025:Titanium