title: Immediate versus delayed loading of dental implants in edentulous patients' maxillae: a 6-year prospective study.
abstract: OBJECTIVE
  This study compared the surgical protocol efficacy of immediate and delayed implant loading in edentulous maxillae opposed by natural or restored mandibular dentitions over an observational period of 6 years or longer. The selected outcome determinants included individual implant survival data, progressive measurements of peri-implant bone resorption, prosthodontic survival and success data, and report of complications.
  
  
  METHODS
  A convenience sample of 49 patients requiring fixed implant-supported maxillary prostheses was split into two groups. The test group (34 patients) was treated according to the Columbus Bridge Protocol, which prescribes the insertion of four to six implants, including distally tilted implants, and load within 24 hours. The control group (15 patients) was treated via a two-stage surgical protocol of 6 to 9 straight implants that were loaded a mean 8.75 months after stage-one implant surgery. Two hundred sixty implants (test: n = 163, control: n = 97) were placed, and all subjects were ultimately treated with screw-retained full-arch prostheses.
  
  
  RESULTS
  Two patients dropped out (one in the test group and one in the control group) by the time of the scheduled sixth annual visit. The other patients were followed up for 75.2 months (range: 72 to 90 months). At the 6-year follow-up, no differences in implant cumulative survival rates were found between groups. Significantly less bone loss was found in the test group (mean: 1.62 mm) compared with the control group (mean: 2.44 mm). All of the original prostheses were maintained throughout the study's observation period and were functioning satisfactorily at each patient's last recall appointment.
  
  
  CONCLUSIONS
  Patients who received immediate and delayed implant loading in their edentulous maxillae demonstrated similar survival outcomes. However, less marginal bone loss was recorded around the immediately loaded implants over the study's 6-year follow-up period.
authors.forename: Tiziano
authors.initials: T
authors.lastname: Tealdo
authors.forename: Maria
authors.initials: M
authors.lastname: Menini
authors.forename: Marco
authors.initials: M
authors.lastname: Bevilacqua
authors.forename: Francesco
authors.initials: F
authors.lastname: Pera
authors.forename: Paolo
authors.initials: P
authors.lastname: Pesce
authors.forename: Alessio
authors.initials: A
authors.lastname: Signori
authors.forename: Paolo
authors.initials: P
authors.lastname: Pera
mesh_terms: D016301:Alveolar Bone Loss / Q000145:classification; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants / Q000009:adverse effects; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation; D003827:Denture, Complete, Upper; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading / Q000009:adverse effects / Q000379:methods*; D007575:Jaw, Edentulous / Q000534:rehabilitation* / Q000601:surgery; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants