title: Immediately restored one-piece single-tooth implants with reduced diameter: one-year results of a multi-center study.
abstract: OBJECTIVE
  The aim of the present multi-center study was to evaluate the treatment outcome of immediately restored one-piece single-tooth implants with a diameter of 3 mm after 1 year.
  
  
  METHODS
  A total of 57 one-piece implants (NobelDirect 3.0) were inserted in 47 patients (26 females, 21 males) with a mean age of 31 years (range: 17-76 years) at five different centers. The implants replaced maxillary lateral incisors and mandibular incisors. The implants were placed either in conjunction with tooth extraction or in healed sites, and all implants were immediately restored with a provisional resin crown. If needed, the abutment part of the implant was prepared before crown cementation. The permanent crown was placed after 1.9-14.5 months. Radiographs were taken at implant insertion as well as after 6 and 12 months to evaluate the peri-implant marginal bone level and bone loss. Moreover, plaque, bleeding on probing and complications were assessed.
  
  
  RESULTS
  A total of 44 patients (23 females, 21 males) with 54 implants were available for the 1-year follow-up. One implant was lost, thus the 1-year implant survival was 98%. A statistically significant mean marginal bone loss was observed between baseline and 6 months (1.1 mm, range: -0.7 to 4.4 mm; n=49) and between baseline and 12 months (1.6 mm, range: -0.8 to 4.6 mm; n=50). A total of 18% of the implants were characterized by a bone loss of more than 3 mm. No bleeding on probing was observed around 83% of the implants. Plaque was registered at 15% of the implants. The most common complications were related to the provisional crown, i.e. fracture (n=3) and loss of retention (n=3).
  
  
  CONCLUSIONS
  A high 1-year implant survival was observed in the present study. However, the excessive peri-implant marginal bone loss around several implants indicates that this implant should be used with caution until further studies have been conducted.
authors.affiliation: Department of Fixed and Removable Prosthodontics and Dental Material Science, School of Dental Medicine, University of Zurich, Zurich, Switzerland. anja.zembic@zzmk.uzh.ch
authors.forename: A
authors.initials: A
authors.lastname: Zembić
authors.forename: L H
authors.initials: LH
authors.lastname: Johannesen
authors.forename: S
authors.initials: S
authors.lastname: Schou
authors.forename: P
authors.initials: P
authors.lastname: Malo
authors.forename: T
authors.initials: T
authors.lastname: Reichert
authors.forename: M
authors.initials: M
authors.lastname: Farella
authors.forename: C H F
authors.initials: CH
authors.lastname: Hämmerle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology; D003094:Collagen; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003794:Dental Restoration, Temporary; D005260:Female; D006801:Humans; D007180:Incisor / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008903:Minerals; D011138:Polytetrafluoroethylene; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013524:Surgical Flaps; D014081:Tooth Extraction; D016896:Treatment Outcome
chemical_list: C106416:Bio-Gide; C077540:Bio-Oss; D008903:Minerals; D011138:Polytetrafluoroethylene; D003094:Collagen