title: Inward-inclined implant platform for the amplified platform-switching concept: 18-month follow-up report of a prospective randomized matched-pair controlled trial.
abstract: OBJECTIVE
  This prospective randomized matched-pair controlled trial aimed to evaluate marginal bone levels and soft tissue alterations at implants restored according to the platform-switching concept with a new inward-inclined platform and compare them with external-hexagon implants.
  
  
  METHODS
  Traditional external-hexagon (control group) implants and inward-inclined platform implants (test group), all with the same implant body geometry and 13 mm in length, were inserted in a standardized manner in the posterior maxillae of 40 patients. Radiographic bone levels were measured by two independent examiners after 6, 12, and 18 months of prosthetic loading. Buccal soft tissue height was measured at the time of abutment connection and 18 months later.
  
  
  RESULTS
  After 18 months of loading, all 80 implants were clinically osseointegrated in the 40 participating patients. Radiographic evaluation showed mean bone losses of 0.5 ± 0.1 mm (range, 0.3 to 0.7 mm) and 1.6 ± 0.3 mm (range, 1.1 to 2.2 mm) for test and control implants, respectively. Soft tissue height showed a significant mean decrease of 2.4 mm in the control group, compared to 0.6 mm around the test implants.
  
  
  CONCLUSIONS
  After 18 months, significantly greater bone loss was observed at implants restored according to the conventional external-hexagon protocol compared to the platform-switching concept. In addition, decreased soft tissue height was associated with the external-hexagon implants versus the platform-switched implants.
authors: Department of Orthodontics and Prosthodontics, University of Bonn, Germany. luigicanullo@yahoo.com
authors: Luigi
authors: L
authors: Canullo
authors: Jose Carlo
authors: JC
authors: Rosa
authors: Vicente Souza
authors: VS
authors: Pinto
authors: Carlos Eduardo
authors: CE
authors: Francischone
authors: Werner
authors: W
authors: Götz
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D001696:Biomechanical Phenomena; D016723:Bone Remodeling / Q000502:physiology*; D001938:Brazil; D059605:Dental Implant-Abutment Design; D015921:Dental Implants / Q000009:adverse effects*; D003773:Dental Plaque / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy; D008297:Male; D016555:Matched-Pair Analysis; D008437:Maxilla; D008875:Middle Aged; D016348:Osseointegration; D011446:Prospective Studies; D011859:Radiography; D012907:Smoking; D018709:Statistics, Nonparametric
chemical_list: D015921:Dental Implants