Introduction:Discoloration of the resin-based composites is a common problem in restorative dentistry. There are many factors associated with the discoloration of dental materials in the oral environment. The purpose of this study was to evaluate the color changes in a nano-composite cured with a quartz-tungsten-halogen (QTH) and light emitting diode (LED) unit. Methods:80 disk-shaped specim...

This study investigated the influence of ceramic thickness and curing unit on light transmission through leucite-reinforced material and polymerization of a dual-cured resin luting agent. Discs of Empress Esthetic (Ivoclar Vivadent) of 0.7-, 1.4- and 2-mm thickness were prepared. Variolink II (Ivoclar Vivadent) was placed in a 1-mm-thick cylindrical mold, and light-activated through ceramic for...

The aim of this study was to evaluate the polymerization shrinkage and shrinkage stress of composites polymerized with a LED and a quartz tungsten halogen (QTH) light sources. The LED was used in a conventional mode (CM) and the QTH was used in both conventional and pulse-delay modes (PD). The composite resins used were Z100, A110, SureFil and Bisfil 2B (chemical-cured). Composite deformation u...

The existence of a formal analogy between quantum energy spectra and discrete time series has been recently pointed out. When the energy level fluctuations are described by means of the n statistic, it is found that chaotic quantum systems are characterized by 1/ f noise, while regular systems are characterized by 1/ f2. In order to investigate the correlation structure of the n statistic, we s...

This study compared the compressive strength of a composite resin and compomer photoactivated with a conventional quartz-tungsten halogen-light (XL 3000, 3M/SPE) and a blue light-emitting diode (LED) (SmartLite PS; Dentsply/De Trey). Forty disc-shaped specimens were prepared using a split polytetrafluoroethylene matrix (4.0 mm diameter x 8.0 mm hight) in which the materials were inserted increm...

We have derived the first, fully-cosmological, similarity solutions for cold dark matter (CDM) halo formation in the presence of nongravitational collisionality (i.e. elastic scattering), which provides an analytical theory of the effect of the self-interacting dark matter (SIDM) hypothesis on halo density profiles. Collisions transport heat inward which flattens the central cusp of the CDM den...

In this article, we study the -stability in qth moment (.s.q.m) of hybrid neutral stochastic differential equations with infinite delay (HNSDEID) using Lyapunov techniques and method M-matrix. Finally, apply main result to some examples.

In order to research the special embankment (thermosyphon embankment) damages and distribution of permafrost under Qinghai–Tibet Highway (QTH) embankment. The section K2952–K2953, which is a typical representative QTH, was chosen for detection in determine sources damages. this study, performance characteristics embankment, active layer, table found ground-penetrating radar (GPR) images were re...