scholarly journals Finite element analysis to study the effects of using CAD/CAM glass-fiber post system in a severely damaged anterior tooth

2015 ◽  
Vol 26 (s1) ◽  
pp. S519-S525 ◽  
Author(s):  
Aijie Chen ◽  
Xiaoli Feng ◽  
Yanli Zhang ◽  
Ruoyu Liu ◽  
Longquan Shao
2016 ◽  
Vol 41 (5) ◽  
pp. E149-E158 ◽  
Author(s):  
VF Wandscher ◽  
CD Bergoli ◽  
IF Limberger ◽  
TP Cenci ◽  
P Baldissara ◽  
...  

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Nagihan Guven ◽  
Ozgur Topuz ◽  
İhsan Yikilgan

Objective. The purpose of this study was to test different restoration combinations used for constructing fractured endodontically treated incisors by reattaching their fractured fragments. Methods. Seven types of 3-D FEM mathematical root canal-filled models were generated, simulating cases of (OB) reattaching fractured fragments; (CrPL) reattaching fractured fragments + ceramic palatinal laminate; (CmPL) reattaching fractured fragments + composite palatinal laminate; (CM) reattaching fractured fragments + coronal 1/3 of the root was filled using core material; (BP) reattaching fractured fragments + glass fiber post; (CP) composite resin restoration + glass fiber post; and (OC) composite resin restoration. A 100-N static oblique force was applied to the simulated teeth with 135° on the node at 2 mm above the cingulum to analyze the stress distribution at the tooth. Results. For enamel tissue, the highest stress values were observed in model BP, and the lowest stress values were observed in model CmPL. For dentine tissue, the highest stress concentrations were observed around the fracture line for all models. Conclusions. Reattachment of fractured fragments by bonding may be preferred as a restoration option for endodontically treated incisors; also, palatinal laminate decreases the stress values at tooth tissues, especially at the enamel and the fracture line.


2013 ◽  
Vol 21 (6) ◽  
pp. 511-517 ◽  
Author(s):  
Priscilla Cardoso LAZARI ◽  
Rodrigo Caldeira Nunes de OLIVEIRA ◽  
Rodolfo Bruniera ANCHIETA ◽  
Erika Oliveira de ALMEIDA ◽  
Amilcar Chagas FREITAS JUNIOR ◽  
...  

2016 ◽  
Vol 36 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Sandro Donnini Mancini ◽  
Antídio de Oliveira Santos Neto ◽  
Maria Odila Hilário Cioffi ◽  
Eduardo Carlos Bianchi

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.


2021 ◽  
Author(s):  
MER Gama ◽  
GS Balbinot ◽  
GC Ferreira ◽  
EG Mota ◽  
VCB Leitune ◽  
...  

SUMMARY This study aimed to evaluate the cementation and mechanical behavior of flared root canals restored with CAD/CAM milled glass fiber post-and-core systems. Sixty-six endodontically treated human canines with a flared root canal were divided into three different groups according to the type of post: GPF received prefabricated posts; GREL received relined glass fiber posts, and GMILLED received CAD/CAM milled glass fiber posts. Cementation was performed with self-adhesive resin cement. The samples were submitted to x-ray microcomputed tomography analysis for the analysis of voids and gaps. The roots were sectioned and submitted to the push-out bond strength test. The load-to-fracture was evaluated in post-and-core systems. GMILLED presented lower void and lower gap volumes when compared to GPF and GREL. On the load-to-fracture test, GREL presented statistically significant higher values than GMILLED. GPF values had no statistically significant difference from the two other groups. On the push-out bond strength test, GPF presented statistically significant lower values when compared to GREL and GMILLED. The most common failure pattern was between dentin and cement in all groups. CAD/CAM milled glass fiber post-and-core systems presented an enhanced adaptation of glass fiber posts to flared root canal systems. Their results were comparable to relined posts in bond strength, while load-to-fracture-results for GMILLED were lower than those for GPF.


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