title: Findings of a Four-Year Randomized Controlled Clinical Trial Comparing Two-Piece and One-Piece Zirconia Abutments Supporting Single Prosthetic Restorations in Maxillary Anterior Region.
abstract: The purpose of this randomized controlled study is to investigate the clinical results obtained over four years and incidence of complications associated with one- versus two-piece custom made zirconia anchorages, in single tooth implant-supported restorations of the maxillary anterior region. Sixty-five patients, with a total of 74 missing maxillary teeth, were selected in the period from February 2007 to July 2010. Two different ways of custom made zirconia abutment and final prosthetic restoration were evaluated: a standard zirconia abutment associated with a pressed layer of lithium disilicate with an all-ceramic cemented restoration versus one-piece restoration with the facing porcelain fired and pressed straight to the custom made zirconia abutment. In 29 cases, the restoration consisted of an all-ceramic restoration for cementation (two pieces); in 45 cases the restoration was a screw-retained restoration (one piece). Three all-ceramic restorations broke during the observation time. Two one-piece restorations fractured after 26 months. At follow-up examination there were no significant differences between one-piece and two-piece groups regarding the PI, BI, and MBL. Awaiting studies with longer follow-up times, a careful conclusion is that zirconia anchorages for single-implant restorations seem to demonstrate good short-term technical and biological results.
authors.affiliation: Private Practice, 80131 Naples, Italy.
authors.forename: Guerino
authors.initials: G
authors.lastname: Paolantoni
authors.affiliation: Division of Oral Surgery and Implantology, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Marenzi
authors.affiliation: Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Blasi
authors.affiliation: Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
authors.forename: Jolanda
authors.initials: J
authors.lastname: Mignogna
authors.affiliation: Division of Oral Surgery and Implantology, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Sammartino
mesh_terms: D019250:Dental Implants, Single-Tooth / Q000009:adverse effects*; D003764:Dental Materials / Q000009:adverse effects* / Q000627:therapeutic use; D003776:Dental Porcelain / Q000009:adverse effects / Q000627:therapeutic use; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000187:drug effects / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D015040:Zirconium / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D003764:Dental Materials; C493120:lithia disilicate; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide