title: Soft tissue response to zirconia and titanium implant abutments: an in vivo within-subject comparison.
abstract: OBJECTIVE
  To compare the health of the soft tissues towards zirconia and titanium abutments in man, as observed using histological data.
  
  
  METHODS
  Twenty patients received two mandibular implants with either a zirconia or titanium abutment (split mouth study design, left-right randomization). After 3 months soft tissue biopsies were prepared for histological evaluation. They were subjected to blind evaluation. The number of blood vessels per surface unit and an inflammation grading scale score ranging from 1 to 4 were determined.
  
  
  RESULTS
  Paired samples from 17 patients were suitable for analysis, 3 with unsevered implant-abutment connections and 14 solely containing soft tissue. All showed a well-keratinized stratified squamous epithelium which was continuous with the barrier (junctional) epithelium that faced the abutment surface. The normal epithelial build-up could be recognized with little signs of inflammation. No statistically significant difference in tissues adjacent to zirconia and titanium abutment surfaces were seen with respect to vascular density (20.5 SD 4.4 and 20.7 SD 3.2) or inflammation grading scale scores (3.2 SD 0.7 versus 3.1 SD 0.7).
  
  
  CONCLUSIONS
  No differences in soft tissue health were seen in peri-implant mucosa adjacent to zirconia and titanium abutment surfaces.
authors.affiliation: Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Ralph
authors.initials: R
authors.lastname: van Brakel
authors.forename: Gert J
authors.initials: GJ
authors.lastname: Meijer
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Verhoeven
authors.forename: John
authors.initials: J
authors.lastname: Jansen
authors.forename: Cornelis
authors.initials: C
authors.lastname: de Putter
authors.forename: Marco S
authors.initials: MS
authors.lastname: Cune
mesh_terms: D000328:Adult; D000368:Aged; D000044:Dental Abutments; D015921:Dental Implants; D003764:Dental Materials / Q000494:pharmacology*; D019094:Dental Prosthesis, Implant-Supported; D003828:Denture, Overlay; D005260:Female; D005881:Gingiva / Q000187:drug effects; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008297:Male; D008334:Mandible; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects*; D016037:Single-Blind Method; D014025:Titanium / Q000494:pharmacology; D015040:Zirconium / Q000494:pharmacology
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide