title: Comparison of two different abutment designs on marginal bone loss and soft tissue development.
abstract: OBJECTIVE
  To assess the response of soft tissues around two different abutment designs in healed sites in the esthetic zone.
  
  
  METHODS
  Twenty-six subjects received two endosseous implants in healed, bilateral implant sites in the esthetic zone in the maxilla or the mandible. After 17 to 19 weeks and left/right randomization, the implants were restored with either a conventional (control) or curved (experimental) titanium abutment and a provisional crown. Eight weeks after abutment placement, definitive crowns were cemented (T0). Soft tissue development was assessed based on peri-implant bone loss, Pink Esthetic Score (PES), and probing depths immediately after placement of the definitive crown and after 1 year (T12) and compared between sites. Possible confounding variables (abutment angle, plaque presence, gingival bleeding, width of attached mucosa) were also documented at T0 and T12.
  
  
  RESULTS
  The mean peri-implant marginal bone loss from T0 to T12 was 0.00 ± 0.37 mm in the experimental group and 0.12 ± 0.27 mm in the control group. Differences were not statistically significant (P = .25). At T12, the curved abutment scored a mean PES of 10 ± 2.3 and the straight abutment scored 9.7 ± 2.3. The difference was not significant (P = .46)). Probing depths were also not significantly different between the two groups (P = .85). Correlation and regression analysis showed no hints of predictive behavior for the possible confounding variables.
  
  
  CONCLUSIONS
  A titanium abutment with a circumferential curved design is of no additional benefit to soft tissue development and preservation of marginal bone compared to a conventional straight abutment design for the restoration of single-tooth implants in the esthetic zone.
authors.forename: Ratnadeep C
authors.initials: RC
authors.lastname: Patil
authors.forename: Laurens
authors.initials: L
authors.lastname: den Hartog
authors.forename: Christiaan
authors.initials: C
authors.lastname: van Heereveld
authors.forename: Aditi
authors.initials: A
authors.lastname: Jagdale
authors.forename: Anjali
authors.initials: A
authors.lastname: Dilbaghi
authors.forename: Marco S
authors.initials: MS
authors.lastname: Cune
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D003442:Crowns; D000044:Dental Abutments / Q000009:adverse effects*; D003758:Dental Implantation, Endosseous / Q000009:adverse effects* / Q000379:methods; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D014025:Titanium
chemical_list: D014025:Titanium