INTRODUCTION Colored compomers are a group of restorative materials that were introduced in 2002 to repair primary teeth, and they provide attractive color and ease of use in pediatric dentistry. The aim of this study was to evaluate the effect of QTH and LED light-curing units on the surface hardness of different colors of Twinky Star compomers. METHODS In this experimental study, a composit...

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...

OBJECTIVES To verify the effect of interposing different indirect restorative materials on degree of conversion (DC), hardness, and flexural strength of a dual-cure resin cement. METHODS Discs (2 mm-thick, n=5) of four indirect restorative materials were manufactured: a layered glass-ceramic (GC); a heat-pressed lithium disilicate-based glass-ceramic veneered with the layered glass-ceramic (L...

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...

The aim of the study was to determine and compare the reaction of rat subcutaneous connective tissue to resin composites polymerized with different lights curing and lightening methods. In this in vivo study, 20 mature Wister Albino rats were used. The composite discs, 4 mm in diameter and 2 mm thick, were cured by QTH or LED light curing units with 4 different lightning methods (full power QTH...

The aim of this study was to determine the effect of different ceramic thickness on heat generation during resin cement photo-activation by QTH (quartz-tungsten-halogen), LED (light emitting diode), and PAC (plasma arc-curing) LCUs (light curing units). The resin cement used was Rely X ARC (3M-ESPE), and the ceramic was IPS Empress Esthetic (Ivoclar-Vivadent), of which 0.7-, 1.4- and 2.0-mm thi...

The aim of this study was to evaluate the effect of light-curing units (LED or halogen) on the marginal adaptation of composite restorations performed with etch-and-rinse and self-etching adhesive. Class V cavities were prepared on bovine teeth with the gingival margin on dentin and the incisal margin on enamel. The cavities were restored with a micro-hybrid resin composite using an etch-and-ri...

The aim of this study was to evaluate the influence of different light sources on the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement. The superficial dentin of human third molars was exposed and acid-etched and an adhesive system was applied (Single Bond 2). Four-mm-thick indirect resin composite restorations (Gradia) were fabricated and cemented u...

The purpose of this study was to compare the polymerization shrinkage stress of composite resins (microfilled, microhybrid and hybrid) photoactivated by quartz-tungsten halogen light (QTH) and light-emitting diode (LED). Glass rods (5.0 mm x 5.0 cm) were fabricated and had one of the surfaces air-abraded with aluminum oxide and coated with a layer of an adhesive system, which was photoactivated...