title: Comparative in vitro study of cementing techniques for implant-supported restorations.
abstract: BACKGROUND
  Various techniques are used to cement implant-supported restorations. Excess residual cement is a concern.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate 3 techniques for cementing implant-supported restorations.
  
  
  METHODS
  Twelve crowns and implant-abutment complexes (IAC) were cemented with 3 techniques: technique 1, a certain amount of cement evenly placed and excess cement removed with an explorer; technique 2, a smaller amount of cement without removal of excess cement; technique 3, a resin abutment replica used for excess cement removal after using a large amount of cement. Each specimen was treated with each technique 3 times. Precementing discrepancies (predis) and postcementing discrepancies (postdis) between IACs and crowns and the postcementing linear roughness (Ra and Rz) on designated junction areas of each specimen were measured. Tensile strength of the specimens was recorded with a universal testing machine at a crosshead speed of 0.5 mm/min. Repeated measures analysis with mixed models was used for differences among the 3 cementing techniques (α=.05).
  
  
  RESULTS
  Compared with techniques 1 and 2, the specimens with technique 3 showed significantly lower mean differences between postdis and predis and Ra and Rz and higher mean tensile strength (P<.05).
  
  
  CONCLUSIONS
  The application of a resin abutment replica for the cementation of implant-supported restorations decreased the discrepancy between the restoration and abutment, reduced cement residue, and increased restoration retention.
authors.affiliation: Student, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Liang
authors.affiliation: Research Scientist and General Practitioner, The Forsyth Institute, Cambridge, Mass; and Adjunct Assistant Professor, Division of General Practice and Materials Science, The Ohio State University College of Dentistry, Columbus, Ohio.
authors.forename: Xingxue
authors.initials: X
authors.lastname: Hu
authors.affiliation: Student, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Research Scientist, Center for Biostatistics, The Ohio State University College of Medicine, Columbus, Ohio.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Pan
authors.affiliation: Professor, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Associate Professor, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China. Electronic address: liujianzhangdr@163.com.
authors.forename: Jianzhang
authors.initials: J
authors.lastname: Liu
mesh_terms: D002484:Cementation / Q000379:methods*; D003442:Crowns; D000044:Dental Abutments; D003738:Dental Cements / Q000009:adverse effects / Q000627:therapeutic use; D019094:Dental Prosthesis, Implant-Supported / Q000379:methods*; D003793:Dental Restoration, Permanent / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques
chemical_list: D003738:Dental Cements