title: Single-tooth implants with different neck designs: a randomized clinical trial evaluating the aesthetic outcome.
abstract: OBJECTIVE
  To evaluate the aesthetic outcome of single-tooth implants in the aesthetic zone with different neck designs from a professional's and patient's perception.
  
  
  METHODS
  Ninety-three patients with a missing anterior tooth in the maxilla were randomly assigned to be treated with an implant with a smooth neck, a rough neck with grooves or a scalloped rough neck with grooves. Implants were installed in healed sites. One year after definitive crown placement (18 months post-implant placement), photographs were taken and the aesthetic outcome was assessed according to two objective aesthetic indexes: pink esthetic score/white esthetic score (PES/WES) and implant crown aesthetic index (ICAI). A questionnaire was used to assess the aesthetic outcome and general satisfaction from a patient's perception. standardized radiographs were taken to measure marginal bone level changes.
  
  
  RESULTS
  One implant was lost. Although there was a significant difference in marginal bone loss between the different implant neck designs (smooth neck 1.19±0.82mm, rough neck 0.90±0.57mm, scalloped neck 2.01±0.77mm), there were no differences in aesthetic outcome. According to the professional's assessments using PES/WES and ICAI, 79.3% and 62% of the cases showed acceptable crown aesthetics, and 59.8% and 56.5% of the cases showed acceptable mucosa aesthetics. Overall, patients were satisfied about the aesthetics of the mucosa (81.5%) and crown (93.3%), and general patient satisfaction was high (9.0±1.0 out of a maximum of 10). According to the professional's assessment, a pre-implant augmentation procedure was associated with less favorable aesthetics of the mucosa.
  
  
  CONCLUSIONS
  This study shows that the aesthetics of single-tooth implants in the maxillary aesthetic zone appears to be independent of the implant neck designs applied but dependent on the need for pre-implant surgery.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Groningen and University of Groningen, Groningen, the Netherlands. l.den.hartog@kchir.umcg.nl
authors.forename: Laurens
authors.initials: L
authors.lastname: den Hartog
authors.forename: Gerry M
authors.initials: GM
authors.lastname: Raghoebar
authors.forename: James J Huddleston
authors.initials: JJ
authors.lastname: Slater
authors.forename: Kees
authors.initials: K
authors.lastname: Stellingsma
authors.forename: Arjan
authors.initials: A
authors.lastname: Vissink
authors.forename: Henny J A
authors.initials: HJ
authors.lastname: Meijer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000145:classification; D000540:Alveolar Ridge Augmentation / Q000379:methods; D064592:Autografts / Q000637:transplantation; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation; D003442:Crowns; D059605:Dental Implant-Abutment Design; D019250:Dental Implants, Single-Tooth; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D004955:Esthetics, Dental; D005260:Female; D005881:Gingiva / Q000473:pathology; D006801:Humans; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D017060:Patient Satisfaction; D023861:Photography, Dental; D014025:Titanium / Q000737:chemistry; D016388:Tooth Loss / Q000534:rehabilitation; D016896:Treatment Outcome; D055815:Young Adult; D015040:Zirconium / Q000737:chemistry
chemical_list: D018786:Bone Substitutes; D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide