This study evaluated the Knoop hardness of Enforce resin cement activated by the either chemical/physical or physical mode, and light cured directly and through ceramic (HeraCeram) or composite resin (Artglass). Light curing were performed with either conventional halogen light (QTH; XL2500) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. Bovine incisors had their buccal surfaces flatte...

The aim of this study was to evaluate the Knoop hardness after 15 min and 24 h of different shades of a dual-cured resin-based cement after indirect photoactivation (ceramic restoration) with 2 light-curing units (LCUs). The resin cement Variolink II (Ivoclar Vivadent) shade XL, A2, A3 and opaque were mixed with the catalyst paste and inserted into a black Teflon mold (5 mm diameter x 1 mm high...

OBJECTIVES The purpose of this study was to evaluate flexural strengths, moduli, and maximum deflection of Clearfil AP-X (APX) and Ceram-X Mono (CXM) when cured with a quartz-tungsten halogen (QTH) or an LED-light (LED). METHODS Specimens were made according to ISO 4049 and cured with QTH or LED for 10, 20 or 60s. Flexural strength, modulus, and deflection were determined after 24 h water sto...

The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and polymerized using different light-curing units and times: conventional QTH (quartz-tungsten-halog...

AIM The purpose of this study was to evaluate the activation of resin-modified glass ionomer restorative material (RMGI, Vitremer-3M-ESPE, A3) by halogen lamp (QTH) or light-emitting diode (LED) by Knoop microhardness (KHN) in two storage conditions: 24 hrs and 6 months and in two depths (0 and 2 mm). MATERIALS AND METHODS The specimens were randomly divided into 3 experimental groups (n = 10...

This study investigated the influence of curing distance on µ-flexural strength (µ-FS) a nano-hybrid composite, cured using manufacturer-recommended time (MCT), compared to consistent radiant exposure (CRE) three different light-curing units (LCUs). Beams (6×2×1 mm) were MCT or CRE with quartz-tungsten-halogen (QTH); single-emission-peak light-emitting-diode (SLED), multiple-emission-peak (MLED...

In the standard cold dark matter (CDM) theory of cosmic structure formation, CDM particles are assumed to be collisionless. The actual identity and microscopic nature of CDM is still unknown, however. It is important, therefore, to explore the consequences of varying this underlying assumption about CDM in the hope that astronomical observations can be used to place meaningful constraints. It h...

For a linear random field (linear p-parameter stochastic process) generated by a dependent random field with zero mean and finite qth moments (q > 2p), we give sufficient conditions that the linear random field converges weakly to a multiparameter standard Brownian motion if the corresponding dependent random field does so. 2000 Mathematics subject classification: 60F17, 60G15.

AIM This study evaluated the in vitro effect of 35% hydrogen peroxide (HP) on surface enamel change when activated with different light curing units (LCUs). MATERIALS AND METHODS Enamel blocks (4 × 4 × 2 mm) were obtained from bovine incisors. The initial microhardness of the enamel was determined for each specimen. After this enamel blocks were randomly divided into four groups (n = 10) and ...

OBJECTIVES The aim of this study was to evaluate the effects of different light sources and curing time on the degree of conversion and microhardness of two surfaces within a nanofilled composite resin. METHODS Four experimental groups (n=10) were formed in accordance with the light source (quartz-tungsten halogen (QTH - 600mW/cm(2)), or light-emitting-diode (LED - 800mW/cm(2))) and the time ...