title: Immediate versus delayed loading of strategic mini dental implants for the stabilization of partial removable dental prostheses: a patient cluster randomized, parallel-group 3-year trial.
abstract: BACKGROUND
  Acceptable short-term survival rates (>90 %) of mini-implants (diameter < 3.0 mm) are only documented for mandibular overdentures. Sound data for mini-implants as strategic abutments for a better retention of partial removable dental prosthesis (PRDP) are not available.
  
  
  METHODS
  The purpose of this study is to test the hypothesis that immediately loaded mini-implants show more bone loss and less success than strategic mini-implants with delayed loading. In this four-center (one university hospital, three dental practices in Germany), parallel-group, controlled clinical trial, which is cluster randomized on patient level, a total of 80 partially edentulous patients with unfavourable number and distribution of remaining abutment teeth in at least one jaw will receive supplementary min-implants to stabilize their PRDP. The mini-implant are either immediately loaded after implant placement (test group) or delayed after four months (control group). Follow-up of the patients will be performed for 36 months. The primary outcome is the radiographic bone level changes at implants. The secondary outcome is the implant success as a composite variable. Tertiary outcomes include clinical, subjective (quality of life, satisfaction, chewing ability) and dental or technical complications.
  
  
  CONCLUSIONS
  Strategic implants under an existing PRDP are only documented for standard-diameter implants. Mini-implants could be a minimal invasive and low cost solution for this treatment modality.
  
  
  BACKGROUND
  The trial is registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00007589 ( www.germanctr.de ) on January 13(th), 2015.
authors.affiliation: Department of Prosthodontics, Greifswald University Hospital, Gerodontology and Dental Materials, Greifswald, Germany. mundt@uni-greifswald.de.
authors.forename: Torsten
authors.identifier: http://orcid.org/0000-0001-6231-1902
authors.initials: T
authors.lastname: Mundt
authors.affiliation: Department of Prosthodontics, Greifswald University Hospital, Gerodontology and Dental Materials, Greifswald, Germany.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Al Jaghsi
authors.affiliation: Private Practice, Greifswald, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Schwahn
authors.affiliation: Private Practice, Drensteinfurt, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Hilgert
authors.affiliation: Department of Oral and Maxillofacial Surgery/Plastic Surgery, Greifswald University Hospital, Greifswald, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lucas
authors.affiliation: Department of Prosthodontics, Greifswald University Hospital, Gerodontology and Dental Materials, Greifswald, Germany.
authors.forename: Reiner
authors.initials: R
authors.lastname: Biffar
authors.affiliation: Department of Prosthodontics, Greifswald University Hospital, Gerodontology and Dental Materials, Greifswald, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schwahn
authors.affiliation: Department of Prosthodontics, Gerodontology and Dental Materials, Private Practice, Morsbach-Lichtenberg, Germany and Greifswald University Hospital, Greifswald, Germany.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Heinemann
mesh_terms: D016301:Alveolar Bone Loss; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005500:Follow-Up Studies; D005858:Germany; D006801:Humans; D008334:Mandible; D011788:Quality of Life; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants
keywords: Implant therapy; Mini dental implant; Partial removable dental prosthesis; Strategic implant; Supplementary abutment