title: Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible.
abstract: OBJECTIVE
  Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated.
  
  
  METHODS
  A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data were evaluated to acquire implant survival rates, implant diameter, gender and age. Panoramic X-rays were analysed for marginal bone loss.
  
  
  RESULTS
  Average surveillance time was 1327 days. Cumulative survival rate (CSR) of short implants was 98% (1 implants lost) compared to 94% in the longer implants group without significance. Thirty-five of the short implants were Astratech (0 losses) and 12 were Camlog Screw Line Promote Plus (1 loss). Early vertical and two-dimensional marginal bone loss was not significantly different in short and regular length implant group with an average of 0.6 mm and 0.7 mm(2) in short implants over the observation period.
  
  
  CONCLUSIONS
  Within the limitations of this study, we conclude that short implants with a length of 9 mm or less have equal survival rates compared with longer implants over the observation period of 1-3 years.
authors.affiliation: Clinic for Oral & Maxillofacial Surgery, University of Mainz, Augustusplatz 2, 55131, Mainz, Germany. draenert@yahoo.com and florian
authors.forename: Florian G
authors.initials: FG
authors.lastname: Draenert
authors.forename: Keyvan
authors.initials: K
authors.lastname: Sagheb
authors.forename: Katharina
authors.initials: K
authors.lastname: Baumgardt
authors.forename: Peer W
authors.initials: PW
authors.lastname: Kämmerer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011862:Radiography, Panoramic; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants