title: Fatigue surviving, fracture resistance, shear stress and finite element analysis of glass fiber posts with different diameters.
abstract: This study evaluated the shear stress presented in glass fiber posts with parallel fiber (0°) and different coronal diameters under fatigue, fracture resistance and FEA. 160 glass-fiber posts (N=160) with eight different coronal diameters were used (DT=double tapered, number of the post=coronal diameter and W=Wider - fiber post with coronal diameter wider than the conventional): DT1.4; DT1.8W; DT1.6; DT2W; DT1.8; DT2.2W; DT2; DT2.2. Eighty posts were submitted to mechanical cycling (3×10(6) cycles; inclination: 45°; load: 50N; frequency: 4Hz; temperature: 37°C) to assess the surviving under intermittent loading and other eighty posts were submitted to fracture resistance testing (resistance [N] and shear-stress [MPa] values were obtained). The eight posts types were 3D modeled (Rhinoceros 4.0) and the shear-stress (MPa) evaluated using FEA (Ansys 13.0). One-way ANOVA showed statistically differences to fracture resistance (DT2.2W and DT2.2 showed higher values) and shear stress values (DT1.4 showed lower values). Only the DT1.4 fiber posts failed after mechanical cycling. FEA showed similar values of shear stress between the groups and these values were similar to those obtained by shear stress testing. The failure analysis showed that 95% of specimens failed by shear. Posts with parallel fiber (0°) may suffer fractures when an oblique shear load is applied on the structure; except the thinner group, greater coronal diameters promoted the same shear stresses.
authors.affiliation: Graduate Program in Oral Science (Prosthodontic Unit), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: viniwan@hotmail.com.
authors.forename: Vinícius Felipe
authors.initials: VF
authors.lastname: Wandscher
authors.affiliation: Division of Prosthodontics, Department of Restorative Dentistry, Federal University of Pelotas, Rio Grande do Sul, Brazil. Electronic address: cesarbergoli@gmail.com.
authors.forename: César Dalmolin
authors.initials: CD
authors.lastname: Bergoli
authors.affiliation: Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: arifoliveira@hotmail.com.
authors.forename: Ariele Freitas
authors.initials: AF
authors.lastname: de Oliveira
authors.affiliation: Graduate Program in Oral Science (Prosthodontic Unit), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: obekaizer@terra.com.br.
authors.forename: Osvaldo Bazzan
authors.initials: OB
authors.lastname: Kaizer
authors.affiliation: Institute of Science and Technology, Univ Est Paulista Julio de Mesquita Filho, São José dos Campos, SP, Brazil. Electronic address: alexanborges@gmail.com.
authors.forename: Alexandre Luiz
authors.initials: AL
authors.lastname: Souto Borges
authors.affiliation: Faculty of Mechanical Engineering, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: oicanis@gmail.com.
authors.forename: Inácio da Fontoura
authors.initials: Ida F
authors.lastname: Limberguer
authors.affiliation: Graduate Program in Oral Science (Prosthodontic Unit), Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: lfvalandro@hotmail.com.
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
mesh_terms: D003764:Dental Materials; D020342:Finite Element Analysis; D005898:Glass; D008422:Materials Testing; D011312:Pressure; D013314:Stress, Mechanical; D013696:Temperature
chemical_list: D003764:Dental Materials; C009753:fiberglass
keywords: Fiber post; Finite element analysis; Fractographic analysis; Fracture strength; Mechanical cycling