title: Influence of platform switching on bone-level alterations: a three-year randomized clinical trial.
abstract: The concept of platform switching has been introduced to implant dentistry based on clinical observations of reduced peri-implant crestal bone loss. However, published data are controversial, and most studies are limited to 12 months. The aim of the present randomized clinical trial was to test the hypothesis that platform switching has a positive impact on crestal bone-level changes after 3 years. Two implants with a diameter of 4 mm were inserted crestally in the posterior mandible of 25 patients. The intraindividual allocation of platform switching (3.3-mm platform) and the standard implant (4-mm platform) was randomized. After 3 months of submerged healing, single-tooth crowns were cemented. Patients were followed up at short intervals for monitoring of healing and oral hygiene. Statistical analysis for the influence of time and platform type on bone levels employed the Brunner-Langer model. At 3 years, the mean radiographic peri-implant bone loss was 0.69 ± 0.43 mm (platform switching) and 0.74 ± 0.57 mm (standard platform). The mean intraindividual difference was 0.05 ± 0.58 mm (95% confidence interval: -0.19, 0.29). Crestal bone-level alteration depended on time (p < .001) but not on platform type (p = .363). The present randomized clinical trial could not confirm the hypothesis of a reduced peri-implant crestal bone loss, when implants had been restored according to the concept of platform switching.
authors.affiliation: Department of Prosthodontics, University of Berne, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Enkling
authors.forename: P
authors.initials: P
authors.lastname: Jöhren
authors.forename: J
authors.initials: J
authors.lastname: Katsoulis
authors.forename: S
authors.initials: S
authors.lastname: Bayer
authors.forename: P-M
authors.initials: PM
authors.lastname: Jervøe-Storm
authors.forename: R
authors.initials: R
authors.lastname: Mericske-Stern
authors.forename: S
authors.initials: S
authors.lastname: Jepsen
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D003442:Crowns; D059605:Dental Implant-Abutment Design; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D009910:Oral Hygiene; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic; D013524:Surgical Flaps / Q000601:surgery; D016019:Survival Analysis; D014945:Wound Healing / Q000502:physiology
keywords: alveolar bone loss; dental implant; dental implant-abutment connection; dental implant-abutment designs; dental implant-abutment interface; single-tooth dental implant