title: Comparison of the Accuracy of Different Transfer Impression Techniques for Osseointegrated Implants.
abstract: The aim of this study was to evaluate 3 transfer techniques used to obtain working casts of implant-supported prostheses through the marginal misfit and strain induced to metallic framework. Thirty working casts were obtained from a metallic master cast, each one containing 2 implant analogs simulating a clinical situation of 3-unit implant-supported fixed prostheses according to the following transfer impression techniques: group A, squared transfers splinted with dental floss and acrylic resin, sectioned, and re-splinted; group B, squared transfers splinted with dental floss and bis-acrylic resin; and group N, squared transfers not splinted. A metallic framework was made for marginal misfit and strain measurements from the metallic master cast. The misfit between the metallic framework and working casts was evaluated with an optical microscope following the single-screw test protocol. In the same conditions, the strain was evaluated using strain gauges placed on the metallic framework. The data were submitted to one-way analysis of variance followed by the Tukey test (α = 5%). For both marginal misfit and strain, there were statistically significant differences between groups A and N (P < .01) and groups B and N (P < .01), with greater values for group N. According to the Pearson test, there was a positive correlation between the misfit and strain variables (r = 0.5642). The results of this study showed that the impression techniques with splinted transfers promoted better accuracy than the nonsplinted technique, regardless of the splinting material used.
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Bruno Massucato
authors.initials: BM
authors.lastname: Zen
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Eveline Freitas
authors.initials: EF
authors.lastname: Soares
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Mariana Agustinho
authors.initials: MA
authors.lastname: Rodrigues
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Leonardo Flores
authors.initials: LF
authors.lastname: Luthi
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Rafael Leonardo X
authors.initials: RL
authors.lastname: Consani
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Marcelo Ferraz
authors.initials: MF
authors.lastname: Mesquita
authors.affiliation: Department of Periodontology and Prosthodontics, Piracicaba Dental School, Campinas State University, São Paulo, Brazil.
authors.forename: Guilherme Elias Pessanha
authors.initials: GE
authors.lastname: Henriques
mesh_terms: D000077280:Bone-Anchored Prosthesis; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003760:Dental Impression Materials; D003761:Dental Impression Technique; D019094:Dental Prosthesis, Implant-Supported; D003765:Models, Dental
chemical_list: D015921:Dental Implants; D003760:Dental Impression Materials
keywords: Implant-supported prostheses; strain gauges; transfer technique