Fatigue surviving, fracture resistance, shear stress and finite element analysis of glass fiber posts with different diameters

2015 ◽  
Vol 43 ◽  
pp. 69-77 ◽  
Author(s):  
Vinícius Felipe Wandscher ◽  
César Dalmolin Bergoli ◽  
Ariele Freitas de Oliveira ◽  
Osvaldo Bazzan Kaizer ◽  
Alexandre Luiz Souto Borges ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Glass Fiber ◽  
Fracture Resistance ◽  
Element Analysis ◽  
Fiber Posts ◽  
Glass Fiber Posts ◽  
Different Diameters

scholarly journals Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

10.2341/08-73 ◽  
2009 ◽  
Vol 34 (2) ◽  
pp. 223-229 ◽  
Author(s):  
A. O. Spazzin ◽  
D. Galafassi ◽  
A. D. de Meira-Júnior ◽  
R. Braz ◽  
C. A. Garbin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Resin Composite ◽  
Resin Cement ◽  
Zirconia Ceramic ◽  
Element Analysis ◽  
Fiber Posts ◽  
Stress Levels ◽  
Glass Fiber Posts

Clinical Relevance According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.

scholarly journals Fractographical Analysis and Biomechanical Considerations of a Tooth Restored With Intracanal Fiber Post: Report of the Fracture and Importance of the Fiber Arrangements

2016 ◽  
Vol 41 (5) ◽  
pp. E149-E158 ◽  
Author(s):  
VF Wandscher ◽  
CD Bergoli ◽  
IF Limberger ◽  
TP Cenci ◽  
P Baldissara ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Fiber ◽  
Shear Stresses ◽  
Fiber Post ◽  
Element Analysis ◽  
Parallel Fibers ◽  
Tooth Structure ◽  
Anterior Teeth ◽  
Compressive Stresses

SUMMARY Objective: This article aims to present a fractographic analysis of an anterior tooth restored with a glass fiber post with parallel fiber arrangement, taking into account force vectors, finite element analysis, and scanning electron microscopy (SEM). Methods: A patient presented at the Faculty of Dentistry (Federal University of Santa Maria, Brazil) with an endodontically treated tooth (ETT), a lateral incisor that had a restorable fracture. The treatment was performed, and the fractured piece was analyzed using stereomicroscopy, SEM, and finite element analysis. Results: The absence of remaining coronal tooth structure might have been the main factor for the clinical failure. We observed different stresses actuating in an ETT restored with a fiber post as well as their relationship with the ultimate fracture. Tensile, compression, and shear stresses presented at different levels inside the restored tooth. Tensile and compressive stresses acted together and were at a maximum in the outer portions and a minimum in the inner portions. In contrast, shear stresses acted concomitantly with tensile and compressive stresses. Shear was higher in the inner portions (center of the post), and lower in the outer portions. This was confirmed by finite element analysis. The SEM analysis showed tensile and compression areas in the fiber post (exposed fibers=tensile areas=lingual surface; nonexposed fibers=compression areas=buccal surface) and shear areas inside the post (scallops and hackle lines). Stereomicroscopic analysis showed brown stains in the crown/root interface, indicating the presence of microleakage (tensile area=lingual surface). Conclusion: We concluded that glass fiber posts with parallel fibers (0°), when restoring anterior teeth, present a greater fracture potential by shear stress because parallel fibers are not mechanically resistant to support oblique occlusal loads. Factors such as the presence of remaining coronal tooth structure and occlusal stability assist in the biomechanical equilibrium of stresses that act upon anterior teeth.

scholarly journals Replacement of metallic parts for polymer composite materials in motorcycle oil pumps

2016 ◽  
Vol 36 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Sandro Donnini Mancini ◽  
Antídio de Oliveira Santos Neto ◽  
Maria Odila Hilário Cioffi ◽  
Eduardo Carlos Bianchi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Transition ◽  
Glass Fiber ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Neutral Medium ◽  
Element Analysis ◽  
Dynamic Mechanical ◽  
Oil Pump

A feasibility study was conducted to determine the use of polyphthalamide/glass-fiber and polyphthalamide/glass-fiber/polytetrafluoroethylene-based composites as substitutes for aluminum and steel, respectively, in the production of motorcycle oil pump parts (housing, shaft/inner gerotor and outer gerotor). New and used (80,000 km) oil pumps were subjected to performance tests, whose results indicated that the pressure and temperature of the used pump reached a maximum of 1.8 bar and 93℃, respectively. Thermogravimetric analysis indicated that the materials are stable at the maximum operating temperature, which is 20℃ lower than the minimum glass transition temperature obtained by dynamic mechanical analysis for both materials at the analyzed frequencies (defined after calculations based on rotations in neutral, medium and high gear). The pressure value was multiplied by a safety factor of at least 1.6 (i.e., 3 bar), which was used as input for a finite element analysis of the parts, as well as the elasticity modulus at glass transition temperatures obtained by dynamic mechanical analysis. The finite element analysis indicated that the von Mises stresses to which the composite parts were subjected are 7 to 50 times lower than those the materials can withstand. The results suggest that it is feasible to manufacture motorcycle oil pump parts with these composites.

scholarly journals Effect of post type and restorative techniques on the strain and fracture resistance of flared incisor roots

2011 ◽  
Vol 22 (3) ◽  
pp. 230-237 ◽  
Author(s):  
Gisele Rodrigues da Silva ◽  
Paulo César de Freitas Santos-Filho ◽  
Paulo Cézar Simamoto-Júnior ◽  
Luis Roberto Marcondes Martins ◽  
Adérito Soares da Mota ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Fracture Resistance ◽  
Composite Resin ◽  
Endodontically Treated Teeth ◽  
Biomechanical Behavior ◽  
Fiber Posts ◽  
Strain Fracture ◽  
Significant Difference ◽  
Catastrophic Failures ◽  
Glass Fiber Posts

Restoring flared endodontically treated teeth continues to be a challenge for clinicians. This study evaluated the effect of post types and restorative techniques on the strain, fracture resistance, and fracture mode of incisors with weakened roots. One hundred five endodontically treated bovine incisors roots (15 mm) were divided into 7 groups (n=15). The two control groups were (C) intact roots restored with Cpc (cast posts and core) or Gfp (glass fiber posts). The five experimental groups were (F) flared roots restored with GfpAp (Gfp associated with accessory glass fiber posts), GfpRc (anatomic Gfp, relined with composite resin), and GfpRcAp (anatomized Gfp with resin and accessory glass fiber posts). All teeth were restored with metal crowns. Mechanical fatigue was performed with 3x10(5)/50 N. Specimens were loaded at 45º, and the strain values (μS) were obtained on root buccal and proximal surfaces. Following that, the fracture resistance (N) was measured. One-way ANOVA and Tukey's HSD tests (α=0.05) were applied, and failure mode was checked. No significant difference in strain values among the groups was found. Cpc presented lower fracture resistance and more catastrophic failures in flared roots. Gfp associated with composite resin or accessory glass fiber posts seems to be an effective method to improve the biomechanical behavior of flared roots.

scholarly journals Fracture Strength and Stress Distribution in Premolars Restored with Cast Post-and-Cores or Glass-Fiber Posts Considering the Influence of Ferule

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Atais Bacchi ◽  
Ricardo Armini Caldas ◽  
Daniel Schmidt ◽  
Mauricio Detoni ◽  
Matheus Albino Souza ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Glass Fiber ◽  
Fracture Strength ◽  
Lower Percentage ◽  
Element Analysis ◽  
Mean Values ◽  
Failure Patterns ◽  
Fiber Posts ◽  
Glass Fiber Posts ◽  
Post And Core

Objectives. The aim of this study was to evaluate the influence of ferule and the post type on the fracture strength and stress distribution in premolars. Materials and Methods. Forty human mandibular premolars were decoronated, allocated in four groups, and restored as follows: CPC-NF: cast post-and-core and absence of ferule; CPC-F: cast post-and-core and presence of ferule; FPC-NF: glass-fiber posts and absence of ferule; FPC-F: glass-fiber posts and presence of ferule. The fracture strength (FS) and failure patterns were evaluated. Finite element analysis (FEA) evaluated the stress distribution. Results. FS did not differ between CPCs and FPC either in presence or in absence of ferule. The presence of ferule increased FS with both post types. Mean values of FS for ferule groups were higher than functional or parafunctional loads reported in literature, which was not the case for FPC-NF when compared to parafunctional loads. FEA with a functional load showed slightly higher compressive stresses in dentin in the group CPC-NF, which was much lower than the compressive strength of dentin. Lower percentage of catastrophic failures was observed in nonferule groups irrespective of post type, which was explained by the stress concentration in the cervical root region when FEA with the FS load was simulated. Conclusion. Ferule effect was shown to be more important than post type in the analysis. Both posts showed potential to withstand functional loads irrespective of presence of ferule. However, the mean FS was lower than parafunctional loads for FPC in the absence of ferule.

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