title: Marginal bone preservation in single-tooth replacement: a 5-year prospective clinical multicenter study.
abstract: BACKGROUND
  Few long-term studies are available comparing immediate and conventional loading protocols of implant-supported single-tooth replacement.
  
  
  OBJECTIVE
  The aim of the present randomized controlled clinical trial was to evaluate prospectively the 5-year clinical and radiological outcome of immediate functional loading implants used in single-tooth replacement.
  
  
  METHODS
  One hundred fifty-one subjects, who required single-tooth rehabilitation in the area from position 15 to 25 and from 35 to 45, were enrolled in eight private clinics in Italy. A randomization protocol was applied to allocate the implants in three treatment groups: one control group and two test groups. In the control group, implant placement was performed according to a conventional drilling procedure, and the implants were submerged for 3 months before abutment connection and loading. Implants allocated in the test group 1 and 2 followed an immediate functional loading protocol. While in test group 1, implant placement was performed according to conventional drilling procedure, in test group 2, a modified implant installation procedure (osteotome technique) was applied. Clinical and radiographic examinations were performed during the 5-year follow-up, and technical and biological complications were registered.
  
  
  RESULTS
  Although four implants (three in the test group 2 and one in the test group 1) were lost in the immediate functional loading groups in the first year of follow-up, no further implant loss occurred in any of the treatment groups in the following monitoring period up to 5 years. No significant differences on marginal bone level changes were observed between the treatment groups. About 52% of all implants showed bone gain in the period from 1-year to 5-year follow-up. The percentage of all implants that in the same interval of time showed bone loss was about 28%. Although few technical complications were recorded in the period of time up to 5 years, implants showing biological complication were 5.7%.
  
  
  CONCLUSIONS
  It is suggested that implants installed with a conventional installation technique together with an immediate functional loading protocol may be considered as a valid treatment alternative in a long-term perspective when used in a single-tooth replacement in an esthetic area.
authors.affiliation: Department of Periodontology, Institute of Odontology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.|private practice, Perugia, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Donati
authors.affiliation: private practice, Pistoia, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: La Scala
authors.affiliation: private practice, Palermo, Italy.
authors.forename: Rosario
authors.initials: R
authors.lastname: Di Raimondo
authors.affiliation: private practice, Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Speroni
authors.affiliation: private practice, Ravenna, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Testi
authors.affiliation: Department of Periodontology, Institute of Odontology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Tord
authors.initials: T
authors.lastname: Berglundh
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000209:etiology; D019250:Dental Implants, Single-Tooth; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading / Q000379:methods*; D007558:Italy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: OsseoSpeed; bone loss; dental implants; immediate loading; single tooth