title: Simplified procedure for the immediate loading of a complete fixed prosthesis supported by four implants in the maxillary jaw: a 2-year prospective study.
abstract: OBJECTIVE
  The aim of this study was to verify the reliability of a system for the fixed retention of complete maxillary prostheses supported by four implants with a follow-up of 2 years.
  
  
  METHODS
  Patients were treated between September 2009 and December 2010 with four Straumann Bone Level SLActive implants supporting a complete prosthesis (CPs). The two distal implants were positioned mesially to the maxillary sinus and with a mesio-distal inclination ≤ 30° in order to reduce the distal prosthesis cantilever. An immediate loading surgical protocol was used. The CPs were planned to be fixed to multibase abutments to test their retention for a fixed rehabilitation. Clinical and radiographic parameters as probing pocket depth (PPD), bleeding score (mBI), plaque index (PI), and marginal bone loss (MBL) were assessed at a 1- and 2-year follow-up visits. Moreover, any biological and prosthodontic maintenance events were recorded. Clinical and radiographic parameters changes were analyzed.
  
  
  RESULTS
  Twenty-one patients treated with a total of 84 implants completed the 2-year examination period. Four patients were lost to follow up. No technical complication was recorded. Also, no implant, reconstruction, or abutment failures were observed. Therefore, an implant and prosthetic survival rate of 100% were achieved after 2 years. The mean periodontal parameter scores after 2 years of function were 2.6 mm for PPD (SD 0.8 mm), 0.3 for mBI (SD 0.5 mm), and 1.2 for PI (SD 0.4 mm) indexes, respectively. In addition, the mean MBL score measured at the 2-year follow-up visit was -0.34 mm (SD of -0.45 mm). Furthermore, no peri-implant soft tissue inflammation or peri-implant infection was observed.
  
  
  CONCLUSIONS
  It has been shown that immediate loading of four implants positioned anteriorly to the maxillary sinus could be a reliable treatment procedure to support fixed complete restorations.
authors: Private practice, Genova, Italy.
authors: Sergio
authors: S
authors: Piano
authors: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors: Eugenio
authors: E
authors: Romeo
authors: Department of Oral Surgery, Dental Clinic, School of Dentistry, University of Padova, Padova, Italy.
authors: Luca
authors: L
authors: Sbricoli
authors: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors: Gianluca
authors: G
authors: Pisoni
authors: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors: Niccoló
authors: N
authors: Cea
authors: Department of Prosthodontics, Dental Clinic, School of Dentistry, University of Milan, Milan, Italy.
authors: Diego
authors: D
authors: Lops
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019094:Dental Prosthesis, Implant-Supported / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies
keywords: complete denture; fixed prosthesis; marginal bone loss; tilted implants