title: A prospective randomized clinical study of changes in soft tissue position following immediate and delayed implant placement.
abstract: OBJECTIVE
  The purpose of this investigation was to compare the efficacy of two therapeutic options-immediate implant placement and ridge preservation with delayed implant placement-in maintaining the position of the soft tissue margins following tooth extraction.
  
  
  METHODS
  This randomized controlled study evaluated apicocoronal changes in the midbuccal and proximal mucosal positions at implant placement sites from tooth extraction to 3 and 6 months following extraction. Twenty-four patients (26 sites) randomly received either immediate implant placement or ridge preservation (grafting with freeze-dried bone allograft and a collagen membrane) followed by implant placement 3 months later. Immediate placement sites received bone grafting for horizontal defects > 2 mm (from implant to cortical wall). Soft tissue measurements, vertical measurements, and ridge width measurements were performed and compared for immediate versus delayed implants and thin versus thick biotype.
  
  
  RESULTS
  The midbuccal soft tissue margins showed minimal recession over 6 months from the time of extraction (mean 0.17 +/- 0.47 mm), with no differences between treatment groups. Interproximal tissue height decreased significantly from extraction to 6 months (mesial, 1.73 +/- 0.71 mm; distal, 1.48 +/- 0.80 mm), with no significant differences between immediate and delayed placement. Immediate implant sites had greater reductions in ridge width 6 months after extraction than delayed placement sites. Tissue biotype failed to show any significant relationship with the changes identified.
  
  
  CONCLUSIONS
  This randomized controlled study comparing soft tissue changes following extraction failed to identify differences between patients treated with immediate or delayed approaches for midbuccal or interproximal soft tissue margins, although greater decreases in ridge width were observed in sites lacking bone grafting. Both immediate and delayed treatment approaches appear to be appropriate following tooth extraction, with the preferred treatment based on factors other than resultant soft tissue changes.
authors.affiliation: Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: van Kesteren
authors.forename: John
authors.initials: J
authors.lastname: Schoolfield
authors.forename: Jason
authors.initials: J
authors.lastname: West
authors.forename: Thomas
authors.initials: T
authors.lastname: Oates
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology; D016025:Bone Transplantation; D003758:Dental Implantation, Endosseous / Q000009:adverse effects / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D019094:Dental Prosthesis, Implant-Supported; D005889:Gingival Recession / Q000209:etiology*; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery*