title: Influence of abutment material on peri-implant soft tissues in anterior areas with thin gingival biotype: a multicentric prospective study.
abstract: OBJECTIVE
  The aim of the present clinical trial was to analyze, through spectrophotometric digital technology, the influence of the abutment material on the color of the peri-implant soft tissue in patients with thin gingival biotype.
  
  
  METHODS
  Thirty-seven patients received an endosseous dental implant in the anterior maxilla. At time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold, titanium and zirconia abutment. Peri-implant soft-tissue color has been measured through a spectrophotometer after the insertion of each single abutment. Also facial peri-implant soft-tissue thickness was measured at the level of the implant neck through a caliper. A specific software has been utilized to identify a standardized tissue area and to collect the data before the statistical analysis in Lab* color space. ΔE parameters of the selected abutments were tested for correlation with mucosal thickness. Pearson correlation test was used.
  
  
  RESULTS
  Only 15 patients met the study inclusion criteria on peri-implant soft-tissue thickness. Peri-implant soft-tissue color was different from that around natural teeth, no matter which type of restorative material was selected. Measurements regarding all the abutments were above the critical threshold of ΔE 8.74 for intraoral color distinction by the naked eye. The ΔE mean values of gold and zirconium abutments were similar (11.43 and 11.37, respectively) and significantly lower (P = 0.03 and P = 0.04, respectively) than the titanium abutment (13.55). In patients with a facial soft-tissue thickness ≤2 mm, the ΔE mean value of gold and zirconia abutments was significantly lower than that of titanium abutments (P = 0.03 and P = 0.04, respectively) and much more close to the reference threshold of 8.74.
  
  
  CONCLUSIONS
  For peri-implant soft tissue of ≤2 mm, gold or zirconia abutments could be selected in anterior areas treatment. Moreover, the thickness of the peri-implant soft tissue seemed to be a crucial factor in the abutment impact on the color of soft tissues with a thickness of ≤2 mm.
authors.affiliation: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Lops
authors.affiliation: Department of Prosthetic Dentistry, School of Dentistry, University of Padova, Padova, Italy.|Department of Neuroscience, Dental Clinic, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Stellini
authors.affiliation: Department of Periodontology, School of Dentistry, University of Padova, Padova, Italy.|Department of Neuroscience, Dental Clinic, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Sbricoli
authors.affiliation: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors.forename: Niccolò
authors.initials: N
authors.lastname: Cea
authors.affiliation: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Romeo
authors.affiliation: Department of Prosthetic Dentistry, School of Dentistry, University of Padova, Padova, Italy.|Department of Neuroscience, Dental Clinic, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Eriberto
authors.initials: E
authors.lastname: Bressan
mesh_terms: D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D003764:Dental Materials; D005260:Female; D005881:Gingiva / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006046:Gold; D006801:Humans; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D011446:Prospective Studies; D013053:Spectrophotometry; D014025:Titanium; D015040:Zirconium
chemical_list: D003764:Dental Materials; D006046:Gold; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: CAD-CAM technology; implant abutment; peri-implant soft tissue; spectrophotometer