title: Volumetric changes and peri-implant health at implant sites with or without soft tissue grafting in the esthetic zone, a retrospective case-control study with a 5-year follow-up.
abstract: OBJECTIVE
  To evaluate the volumetric changes and peri-implant health at implant sites with and without previous soft tissue grafting over a 5-year observation period.
  
  
  METHODS
  In 18 partially edentulous patients, dental implants were placed in the esthetic zone (15-25) with simultaneous guided bone regeneration, followed by submerged healing. During the healing phase, eight patients (test) received a subepithelial connective tissue graft, whereas 10 patients (control) did not receive any soft tissue augmentation. Subsequently, abutment connection was performed and final reconstructions were inserted. Impressions were taken 1 week after crown insertion and at 5 years. Obtained casts were scanned and superimposed for volumetric and linear measurements. The mean distance (MD) in the mid-buccal area between the two surfaces and the differences in buccal marginal mucosal level (bMMLchange) and in ridge width (RWchange) were evaluated. Peri-implant health was assessed using probing pocket depth (PPD) values, plaque index (PlI) and bleeding on probing (BOP).
  
  
  RESULTS
  At a median follow-up time of 60.5 months a median MD of -0.38 mm (Min: -0.94; Max: -0.03) (test) and of -0.51 mm (Min: -0.76; Max: 0.05) (control) was calculated. The level of the margo mucosae (bMMLchange) demonstrated a median loss of -0.42 mm (Min: -1.1; Max: -0.01) (test) and of -0.33 mm (Min: -1.02; Max: 0.00) (control). The median RWchangeranged between -0.44 mm and -0.73 mm (test) and between -0.49 mm and -0.54 mm (control). Mean PPD values slightly increased, whereas PlI and BOP remained stable over time in both groups. None of the comparisons between the groups revealed statistically significant differences (P > 0.35). A small sample size must be considered, however.
  
  
  CONCLUSIONS
  Limited by a retrospective case-control study design, implant sites with and without soft tissue grafting on the buccal side revealed only minimal volumetric and linear changes and stability of peri-implant parameters over 5 years.
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Bienz
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Vitor M
authors.initials: VM
authors.lastname: Sapata
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Christoph H F
authors.initials: CHF
authors.lastname: Hämmerle
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Hüsler
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Thoma
mesh_terms: D000328:Adult; D000368:Aged; D000069343:Bone-Implant Interface / Q000473:pathology* / Q000601:surgery; D016022:Case-Control Studies; D003758:Dental Implantation, Endosseous / Q000009:adverse effects; D004955:Esthetics, Dental; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000637:transplantation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010519:Periodontium / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies
keywords: dental implants; fixed partial denture; subepithelial connective tissue graft; volume stability; volumetric analysis