title: Comparison of Clinical and Radiographic Outcomes of Platform-Switched Implants with a Rough Collar and Platform-Matched Implants with a Smooth Collar: A 1-Year Randomized Clinical Trial.
abstract: OBJECTIVE
  The aim of this study was to evaluate and compare the clinical and radiographic outcomes of single implants with a platform-switched rough collar (PSRC) and a platform-matched smooth collar (PMSC).
  
  
  METHODS
  Twenty-six patients missing a tooth in the anterior maxilla (through the premolars) were randomly assigned to the PSRC or the PMSC group. All implants were placed in a flapless approach and restored with an early loading protocol. Clinical measurements were performed at surgery, loading, and at 3, 6, and 12 months after loading. In addition, radiographic evaluations were carried out using standardized periapical radiographs and cone beam computed tomography. Patient satisfaction surveys were completed, and microbial analysis with DNA probes was performed.
  
  
  RESULTS
  The implant survival rate was 100% for both groups. The mean marginal bone level (MBL) was significantly higher in the PSRC group compared to the PMSC group at all time points. From the 2-week postoperative visit to 1 year postloading, the mean MBL change in the PSRC group was 0.21 ± 0.56 mm and in the PMSC group it was 0.74 ± 0.47 mm. Soft tissue profiles were stable over time, with no significant differences between groups. There were no significant differences between groups in the number of microbial species seen. Patients in both groups were highly satisfied with postoperative and postprosthetic experiences.
  
  
  CONCLUSIONS
  In this study, the PSRC method preserved marginal bone by a mean of 0.53 mm more than the standard PMSC protocol. Within the limitations of the present study, it can be concluded that the PSRC protocol may be beneficial in marginal bone preservation. Longitudinal studies are needed to verify the long-term effects of this approach.
authors.forename: Yung-Ting
authors.initials: YT
authors.lastname: Hsu
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.forename: Ivan
authors.initials: I
authors.lastname: Rudek
authors.forename: Jill
authors.initials: J
authors.lastname: Bashutski
authors.forename: Won-Suk
authors.initials: WS
authors.lastname: Oh
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
authors.forename: Tae-Ju
authors.initials: TJ
authors.lastname: Oh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000382:microbiology; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003442:Crowns; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods; D019250:Dental Implants, Single-Tooth / Q000382:microbiology; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000000981:diagnostic imaging / Q000382:microbiology; D006801:Humans; D057893:Immediate Dental Implant Loading; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000382:microbiology / Q000601:surgery; D008875:Middle Aged; D017060:Patient Satisfaction; D016300:Radiography, Bitewing / Q000379:methods; D013499:Surface Properties; D016896:Treatment Outcome