Search results for "Versa"

In vitro comparison of flexural strength and elastic modulus of three provisional crown materials used in fixed prosthodontics

2013

Objectives: To evaluate and compare the flexural strength and the elastic moduli of three provisional crown materials (methyl methacrylate based autopolymerized resin, bis acryl composite based autopolymerized resin and urethane dimethacrylate based light polymerized resin) after storing in artificial saliva and testing at intervals of 24 hours and 7 days. Study design: A metal master mould with four slots of dimensions 25x2x2 mm was fabricated to obtain samples of standard dimensions. A total of 135 specimens were thus obtained with 45 each of three provisional materials. Further 15 samples of each group were tested after storing for one hour at room temperature and again at intervals of 2…

Impact of freezing rate on electrical conductivity of produce

2013

The aim of this work was to compare the effects of freezing rate on electrical conductivity of potatoes, carrots and apples. Electrical conductivity tests were conducted on a custom ohmic cell while samples texture was measured by means of a universal testing machine. The raw un-pretreated samples were used as control. This study showed that freezing pre-treatments lead to differences in electrical conductivity of considered samples, producing structural damage, the latter being relatively more severe when the tested products undergo ohmic treatment.

Role of coefficient of thermal expansion on bond strength of ceramic veneered yttrium-stabilized zirconia

2017

Background Incompatible coefficient of thermal expansion (CTE) is supposed to be a reason for chipping of ceramic veneered zirconia. This study evaluates the effect of veneering ceramic at varied CTE on bond strength to zirconia. Material and Methods Zirconia disks (Z, O 10 mm, 1.0 mm thickness) were prepared from Y-TZP (Cercon®) and sintered at 1350°C for 6 hours. All zirconia disks were veneered with ceramics ((O 7.0 mm, 1.5 mm thickness) with varied CTE including VITADur® alpha (VDα), VITAVM®7 (VM7), VITAVM®9 (VM9), Cercon® ceramkiss (CCK), IPSe.max® ceram (IeC), and IPS dSIGN® (IdS) (n=15). The specimens were thermo-cycled (5-55 °C, 500 cycles) prior to determine the shear bond strength…

Effect of different sintering process on flexural strength of translucency monolithic zirconia

2018

Background Sintering process is responsible for the strength of zirconia restoration. This study evaluated the effect of different sintering temperatures and sintered-holding times on flexural strength of translucency monolithic zirconia. Material and Methods One hundred and thirty five zirconia bar specimens (width-length-thickness = 10×20×1.5 mm) were prepared from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic and randomly divided into nine groups to be sintered at different temperatures [decreasing- (SD, 1350°C), regular- (SR, 1450°C), and increasing- (SI, 1550°C) sintering temperature] and different sintered-holding times [shortening- (HS, 60 min), regular- (HR, …

Fracture resistance of roots filled with three different obturation techniques

2012

Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was…

Influence of artificial aging and ZrO2 nanoparticle-reinforced repair resin on the denture repair strength

2019

Background The purpose of this study was to evaluate the effect of aging process on the tensile strength (TS) of repaired acrylic denture base using ZrO2 nanoparticles (nano-ZrO2)-reinforced autopolymerized resin. Material and Methods A total of 240 heat-polymerized acrylic resin specimens (n=10) were prepared and sectioned creating 2 mm-repair-gap. Autopolymerized acrylic resin, pure and modified with 2.5, 5, and 7.5wt% nano-ZrO2 were used for specimens repair. TS of repaired specimens were measured using the universal testing machine after water immersion at 37oC for 2, 7 and 30 days. At each time interval, half the immersed specimens underwent thermo-cycling aging process (5000 cycles at…

Health care financing through micro insurance in Cameroon : a prelude to Universalism

2014

Spazi di universalità. la dialettica della abstrakte Allgemeinheit in Hegel

2014

Universalità della Ragione. Pluralità delle Filosofie nel Medieoevo | Universalité de la Raison. Pluralité des philosophies au Moyen Âge | Universali…

2012

Universalità e analogia: metafisica e logica nel pensiero islamico

2012

Il discorso su universalità e analogia rispetto alla ragione, nell’orizzonte storico del pensiero islamico medievale, ha guadagnato l’esplicitazione dell’analogia ipotetica come analogia fondamentale ed è orientato verso la discussione sul rapporto analogico tra analogia logica ed analogia metafisica: è mediante l’analogia che la ragione estende l’universalità del suo dominio dall’esistente al principio sia dell’essere sia del conoscere, ma il passaggio dall’analogia logica all’analogia metafisica dell’esistente richiede la costruzione di una teoria generale dell’universalità, che renda possibile il discorso sull’analogia tra esistente e principio. L’esplicitazione dell’analogia ipotetica c…