Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

2017 ◽  
Vol 68 (1) ◽  
pp. 94-100
Author(s):  
Oana Tanculescu ◽  
Adrian Doloca ◽  
Raluca Maria Vieriu ◽  
Florentina Mocanu ◽  
Gabriela Ifteni ◽  
...  

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

2009 ◽  
Vol 42 (7) ◽  
pp. 844-849 ◽  
Author(s):  
Filip Keulemans ◽  
Lippo V.J. Lassila ◽  
Sufyan Garoushi ◽  
Pekka K. Vallittu ◽  
Cornelis J. Kleverlaan ◽  
...  

2011 ◽  
Vol 27 (6) ◽  
pp. e107-e115 ◽  
Author(s):  
Anna-Maria Le Bell-Rönnlöf ◽  
Lippo V.J. Lassila ◽  
Ilkka Kangasniemi ◽  
Pekka K. Vallittu

2006 ◽  
Vol 7 (4) ◽  
pp. 1-8 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan K. Garoushi ◽  
Arzu Tezvergil

Abstract Aim The aim of this study was to determine the static load-bearing capacity of composite resin onlay restorations made of particulate filler composite (PFC) with two different types of fiber-reinforced composite (FRC) substructures. In addition, flexural properties of the material combination and the effect of polymerization devices were tested. Methods and Materials Specimens were prepared to simulate an onlay restoration, which consisted of 2 to 3 mm of FRC layer as a substructure (short random and continuous bidirectional fiber orientation) and a 1 mm surface layer of PFC. Control specimens were prepared from plain PFC. In Group A the specimens were incrementally polymerized only with a hand-light curing unit for 40 s, while in Group B the specimens were post-cured in a light-curing oven for 15 min before they were statically loaded with a steel ball. Bar-shaped test specimens were prepared to measure the flexural properties of material combination using a three-point bending test (ISO 10477). Results Analysis of variance (ANOVA) revealed all specimens with a FRC substructure have higher values of static load-bearing capacity and flexural properties than those obtained with plain PFC (p<0.001). Conclusion The load-bearing capacity of all the specimens decreased after post-curing and water storage. Restorations made from a material combination of FRC and PFC showed better mechanical properties than those obtained with plain PFC. Citation Garoushi SK, Lassila LVJ, Tezvergil A, Vallittu PK. Fiber-reinforced Composite Substructure: Loadbearing Capacity of an Onlay Restoration and Flexural Properties of the Material. J Contemp Dent Pract 2006 September;(7)4:001-008.


2012 ◽  
Vol 204-208 ◽  
pp. 995-998
Author(s):  
Yun Yun Li ◽  
Bao Sheng Yang

This paper studies the working mechanism, ductility, and ultimate load bearing capacity of the composite columns through axial load bearing capacity experiments on eight steel skeleton-steel pipes reinforced composite concrete columns. The results show that the collaborative work between the steel pipe, steel skeleton and concrete can effectively improve the bearing capacity of the column, delay or inhibit the spread of shear diagonal cracks in the concrete and improve the ductility of the column. In addition, the finite element software ANSYS is used to digitally simulate the whole process of axial pressure test, and the resulting load-displacement curves and experimental curves agree fairly well.


2007 ◽  
Vol 18 (10) ◽  
pp. 2025-2031 ◽  
Author(s):  
Ahmed Mansour Ballo ◽  
Lippo V. Lassila ◽  
Pekka K. Vallittu ◽  
Timo O. Närhi

Author(s):  
А.V. Perelmuter ◽  
◽  
V.V. Yurchenko ◽  

Abstract. The main purpose of the research was a deep analysis and verification of the consistency and completeness of the design code relating to calculation of load-bearing structural members made from cold-formed profiles. The work has been done in close connection with the implementation on the territory of Ukraine of this design code. The article has discussed and investigated the load-bearing capacity of structural members made of cold-formed profiles subjected to the action of central compression. A system of constraints has been presented, in which the strength and buckling constraints for thin-walled cold-formed column members are formulated, taking into account their possible post-buckling behavior, namely, the ability to resist external loads and effects even after the occurrence of the local buckling and/or distortional buckling phenomenon. The performed load-bearing capacity investigation has shown that for the mono-symmetric cold-formed profiles, the flexural-torsional buckling is determinative. For such cold-formed profiles, the effect of the overall dimensions ratio (flange width to web height) on the load-bearing capacity of cold-formed profiles has been estimated. It has been shown that for the same cross-sectional area the load-bearing capacity of a column structural member made from cold-formed profile and subjected to axial compression can be significantly increased by assigning an optimal ratio of flange width to web height. The paper also has presented the results of the load-bearing capacities for the structural cold-formed members subjected to central compression, calculated according to the design standard DSTU-N B EN 1993-1-3: 2012 and according to the design code DBN V.2.6-198: 2014. It has been shown that in some cases the difference in the assessment of the load-bearing capacity for such structural cold-formed members reached 25%. A comparison of the load-bearing capacities for the action of the central compression has been made for structural cold-formed members made from a C-shaped profile and with a composite section of two C-shaped profiles. It has been shown that the load-bearing capacity of the structural cold-formed member of the composite section exceeds the load-bearing capacity of the member with single C-shaped profile by more than 3 times, while cross-section areas of these structural members differ only doubly.


Author(s):  
Ana Piquer Vicent ◽  
David Hernández-Figueirido ◽  
Carmen Ibáñez Usach

In the past, many works to study the mechanical behaviour of concrete filled steel tubular (CFST) stub columns have been conducted. Some of the applications of these composite columns oblige to meet higher requirements of ductility and load-bearing capacity. Traditionally, circular and rectangular tubes have been employed but recently new cross-sectional shapes of these composite columns are being designed and investigated with the aim of optimizing their mechanical behaviour. In this line, concrete-filled round-ended steel tubular columns (CFRT) have appeared as an alternative. However, the number of experimental programs to characterize their mechanical response is still scarce. In order to contribute to the test results database, in this paper an experimental study of 9 concrete-filled round-ended steel tubular stub columns is presented. All the specimens were designed with the same cross-sectional round-ended shape and have the same dimensions. In this program, both normal and high-strength concrete were employed as infill. During the tests, the columns were subjected to axial compression loads but under different eccentricities. The influence of eccentricity and concrete strength on the ultimate load bearing capacity of the concrete-filled round-ended steel tubular are discussed. Besides, the combined action of both components in this type of concrete-filled tubes as well as the effect of the concrete infill are studied.


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