Cemented Versus Screw-Retained Implant-Supported Single-Tooth Crowns: A 4-year Prospective Clinical Study

Purpose: The purpose of this controlled prospective clinical study was to compare cemented and screw-retained implant-supported single-tooth crowns followed for 4 years following prosthetic rehabili-tation with respect to peri-implant marginal bone levels, peri-implant soft tissue parameters, and pros-thetic complications. Materials and Methods: Twelve consecutive patients were selected from a patient population attending the Implantology Department at the University of Padova. They all pre-sented with single-tooth bilateral edentulous sites in the canine/premolar/molar region with adequate bone width, similar bone height at the implant sites, and an occlusal scheme that allowed for the establishment of identical occlusal cusp/fossa contacts. Each patient received 2 identical implants (1 in each edentulous site). One was randomly selected to be restored with a cemented implant-sup-ported single-tooth crown, and the other was restored with a screw-retained implant-supported single-tooth crown. Data on peri-implant marginal bone levels and on soft tissue parameters were collected 4 years after implant placement and analyzed to determine whether there was a significant difference with respect to the method of retention (cemented versus screw-retained). Results: All patients com-pleted the study. All 24 implants survived, resulting in a cumulative implant success rate of 100%. Sta-tistical analysis revealed no significant differences between the 2 groups with respect to peri-implan