title: Early, delayed, or late single implant placement: 10-year results from a randomized controlled clinical trial.
abstract: OBJECTIVE
  The aim of this study was to present the 10-year clinical and radiographic data from a RCT on single-tooth implants placed early, delayed, or late after tooth extraction.
  
  
  METHODS
  Sixty-three patients were randomly allocated to three groups and received an implant on average 10 days (Ea), 3 months (De), or 17 months (La) after tooth extraction. Second-stage surgery was performed after 3 months of submerged healing; metal-ceramic crowns were cemented after one additional month. Standardized periapical radiographs were taken 1 week after implant placement (TP), 1 week (TC) and 1-1.5 year (T1) after crown delivery, and 10 years after implant placement (T10). Pocket depth (PD) and bleeding on probing were registered during controls (TC - T10).
  
  
  RESULTS
  Two Ea and one De implants failed to osseointegrate. Seven patients (4 Ea, 1 De, and 2 La) were not available at T10 . No significant differences were found among groups regarding implant survival or radiographic peri-implant marginal bone levels (Ea: 1.15 ± 0.77; De: 1.53 ± 1.06; La: 1.42 ± 1.07) at T10 . Similarly, no differences were observed among groups in the number of implants with PD ≥ 5 mm (Ea: 29%; De: 35%; La: 44%) or the average depth of the sites with PD ≥ 5 mm (Ea: 5.4 ± 0.7; De: 6.1 ± 1.4; La: 5.4 ± 0.5) at T10 . Peri-implant mucositis was found in 70% of the cases; peri-implantitis was diagnosed only in two implants (1 De, 1 La) corresponding to 4.3%.
  
  
  CONCLUSIONS
  Single-tooth implants placed early or delayed after tooth extraction show high survival rates and limited peri-implant marginal bone resorption or biological complications, similar to what is observed with implants placed according to the conventional (late) protocol.
authors.affiliation: Prosthetic Dentistry, Department of Dentistry, Aarhus University, Aarhus, Denmark; Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Schropp
authors.forename: Ann
authors.initials: A
authors.lastname: Wenzel
authors.forename: Andreas
authors.initials: A
authors.lastname: Stavropoulos
mesh_terms: D000328:Adult; D000368:Aged; D064592:Autografts / Q000637:transplantation; D016025:Bone Transplantation / Q000379:methods; D002484:Cementation / Q000379:methods; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000209:etiology; D016300:Radiography, Bitewing / Q000379:methods; D012907:Smoking; D013280:Stomatitis / Q000209:etiology; D016019:Survival Analysis; D014081:Tooth Extraction / Q000379:methods; D055815:Young Adult
chemical_list: D016876:Metal Ceramic Alloys
keywords: delayed implantation; dental implant; early implantation; late implantation; randomized controlled trial; single-tooth