title: Different performance of platform switching in equicrestal position implant: an histological study.
abstract: OBJECTIVE
  In this study we tested two different type of implant systems that were selected on the basis of differences in macrogeometry of platform switching in order to evaluate the behavior in term of BIC on the platform.
  
  
  METHODS
  The patients were divided in two groups (Group I and II); group I was composed by 4 patients that each received in the posterior areas of mandible one type A implant (3,6 mm in diameter and 6,5 mm in length GTBPlan1Health Amaro (UD) Italy) one type B implant (4 mm in diameter and 8 mm in length OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). Group II was composed by 3 patients that each received in the posterior areas of jawsbone one type A implant [3,6 mm in diameter and 6,5 mm in length GTB- Plan1Health Amaro, (UD), Italy] one type B implant (4 mm in diameter and 8 mm in length OsseoSpeed Astra Tech, Dentsply Molndal, Sweden). All the implants were placed, by the same operator, in equicrestal position using "one stage" technique with a healing abutment at an adequate gingival height. After 12 weeks of healing all the implants of both groups were harvested with the peri-implant bone tissues. BIC upon platform was calculated considering as implant surface the platform length.
  
  
  RESULTS
  Our results showed that the mean percentage of BIC value related to platform surface placed in equicrestal position was higher in patients with type A implant than patients receiving type B implant independently from mandibular or maxillary positions. Moreover the mean percentage of BIC related to platform surface was significantly (p<0.05) higher in Group II/A than Group I/A.
  
  
  CONCLUSIONS
  Our data highlights that the particular features of the Bioplatform of Type A implant systems guarantee a higher value of BIC even if the implants were placed equicrestally.
authors.affiliation: Private Practice, Chieti, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Rocci
authors.affiliation: Department of Social Dentistry, National Institute for Health, Migration and Poverty, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Calcaterra
authors.affiliation: Private Practice, Chieti, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rocci
authors.affiliation: Private Practice, Chieti, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Rocci
authors.affiliation: School of Dentistry, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: DI Girolamo
authors.affiliation: Department of Social Dentistry, National Institute for Health, Migration and Poverty, School of Dentistry, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Baggi
keywords: histomorphometry; macrogeometry; microgeometry