title: Immediate versus delayed loading of dental implants in edentulous maxillae: a 36-month prospective study.
abstract: OBJECTIVE
  The aim of this study was to compare survival rates and radiographic outcomes of immediate and delayed implant loading in edentulous maxillae.
  
  
  METHODS
  Forty-nine patients in need of maxillary full-arch treatment were randomized into two groups: test group (n = 34) treated following the Columbus Bridge Protocol with 4 to 6 implants loaded within 24 hours and a control group (n = 15) treated following the ad modum Branemark protocol with 6 to 9 implants loaded a mean 8.75 months after surgery. Two hundred sixty implants (test: n = 163, control: n = 97) were placed, and subjects were treated with screw-retained full-arch prostheses. Bone levels were measured at baseline and at 1, 2, and 3 years and analyzed using repeated-measures analysis of variance.
  
  
  RESULTS
  All patients appeared at all scheduled recall visits. No differences in cumulative survival rates were found between groups at 36 months. Ten implants (6.1%) failed in the test group; four (4.1%) failed in the control group. At 36 months, no prosthetic failures were detected. Significantly less bone loss was found in the test group at all time intervals (P < .001). The average bone level from the implant-abutment connection was 1.3 mm in the test group and 1.9 mm in the control group at 12 months, 1.5 mm and 2.2 mm at 24 months, and 1.6 mm and 2.3 mm at 36 months, respectively.
  
  
  CONCLUSIONS
  In the edentulous maxilla, the Columbus Bridge Protocol involving immediate loading of implants placed in both healed and fresh extraction sites exhibited equivalent implant survival and less marginal bone loss at 3 years compared to the conventional two-stage delayed loading protocol. Int J Prosthodont 2011;24:294-302.
authors.forename: Tiziano
authors.initials: T
authors.lastname: Tealdo
authors.forename: Marco
authors.initials: M
authors.lastname: Bevilacqua
authors.forename: Maria
authors.initials: M
authors.lastname: Menini
authors.forename: Francesco
authors.initials: F
authors.lastname: Pera
authors.forename: Giambattista
authors.initials: G
authors.lastname: Ravera
authors.forename: Carl
authors.initials: C
authors.lastname: Drago
authors.forename: Paolo
authors.initials: P
authors.lastname: Pera
mesh_terms: D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D005500:Follow-Up Studies; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D011446:Prospective Studies
chemical_list: D015921:Dental Implants