title: The effect of casting and masticatory simulation on strain and misfit of implant-supported metal frameworks.
abstract: The influence of casting and masticatory simulation on marginal misfit and strain in multiple implant-supported prostheses was evaluated. Three-unit screw retained fixed dental prosthesis (FDP) and screw retained full-arch fixed dental prosthesis (FAFDP) frameworks were made using calcinable or overcasted cylinders on conical dental implant abutment. Four groups were obtained according to the cylinder and prosthesis type (n=10). Frameworks were casted in CoCr alloy and subjected to strain gauge analyses and marginal misfit measurements before and after 10(6) mechanical cycles (2 Hz/280 N). Results were submitted to ANOVA, Tukey's HSD and Pearson correlation test (α=0.05). No difference was found on misfit among all groups and times (p>0.05). Overcasted frameworks showed higher strain than the calcinable ones (FDP - Initial p=0.0047; Final p=0.0004; FAFDP - Initial p=0.0476; Final p=0.0115). The masticatory simulation did not influence strain (p>0.05). No correlation was observed between strain and misfit (r=0.24; p>0.05). In conclusion, the marginal misfit value in the overcasted full-arch frameworks was higher than clinical acceptable data. It proved that overcasted method is not an ideal method for full-arch prosthesis. Overcasted frameworks generate higher strain upon the system. The masticatory simulation had no influence on misfit and strain of multiple prostheses.
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil.
authors.forename: Cláudia Lopes Brilhante
authors.initials: CL
authors.lastname: Bhering
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil.
authors.forename: Isabella da Silva Vieira
authors.initials: Ida S
authors.lastname: Marques
authors.affiliation: Department of Prosthodontics, Health Sciences Graduate School, Amazonas State University, Manaus, Amazonas, Brazil.
authors.forename: Jessica Mie Ferreira Koyama
authors.initials: JM
authors.lastname: Takahashi
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil. Electronic address: vbarao@unicamp.br.
authors.forename: Valentim Adelino Ricardo
authors.initials: VA
authors.lastname: Barão
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil.
authors.forename: Rafael Leonardo Xediek
authors.initials: RL
authors.lastname: Consani
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil.
authors.forename: Marcelo Ferraz
authors.initials: MF
authors.lastname: Mesquita
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry*; D000044:Dental Abutments; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D008962:Models, Theoretical
chemical_list: D002858:Chromium Alloys
keywords: Cyclic loading; Marginal misfit; Multiple prostheses; Prosthetic cylinder; Strain gauges; Stress analysis