title: Biomechanical study in polyurethane mandibles of different metal plates and internal fixation techniques, employed in mandibular angle fractures.
abstract: The aim of this study was to perform a physicochemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures. Twenty-eight polyurethane mandibles were uniformly sectioned on the left angle. These were divided into 4 groups: group Eng 1P, one 2.0-mm plate and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates, the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the Ti-15Mo alloy. Each group was subjected to linear vertical loading at the first molar on the plated side in a mechanical testing unit. Means and standard deviations were compared with respect to statistical significance using ANOVA. The chemical composition of the Ti-15Mo alloy was close to the nominal value. The mapping of Mo and Ti showed a homogeneous distribution. SEM of the screw revealed machining debris. For the plates, only the cpTi plate undergoes a surface treatment. The metallographic analysis reveals granular microstructure, from the thermomechanical trials. A statistically significant difference was found (P < 0.05) when the comparison between both internal fixation techniques was performed. The 2P technique showed better mechanical behavior than 1P.
authors.forename: Fernando Pozzi
authors.initials: FP
authors.lastname: Semeghini Guastaldi
authors.forename: Eduardo
authors.initials: E
authors.lastname: Hochuli-Vieira
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Guastaldi
mesh_terms: D000497:Alloys / Q000737:chemistry; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D003799:Dental Stress Analysis / Q000295:instrumentation; D004867:Equipment Design; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008337:Mandibular Fractures / Q000601:surgery*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008953:Models, Anatomic; D017942:Nitric Acid / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D000497:Alloys; D011140:Polyurethanes; C525450:titanium molybdenum alloy; C031462:titanium alloy (TiAl6V4); D017942:Nitric Acid; D014025:Titanium; D006858:Hydrofluoric Acid