We apply terahertz (THz) time-domain spectroscopy for monitoring the curing process of three different light-curing dental composites. Exact knowledge of the sample thickness is required for a precise determination of the THz dielectric parameters, as the materials exhibit shrinkage when they are cured. We find very small but significant changes of the THz refractive index and absorption coeffi...

Three concrete mix proportions were designed and prepared, respectively, such as fly ash concrete (abbreviated as “FAC”) with 30% fly ash replacement ratio of cement, fly ash, and slag concrete (abbreviated as “FSC”) with each of 20% fly ash and slag replacement ratio and ordinary Portland cement concrete (abbreviated as “OPC”) for the research of carbonation and chloride resistance of concrete...

Purpose: This study evaluated the effect of a high-power solid-state light emitting diode (LED) curing unit on the dentin bond strength of a composite resin with self-etching primer adhesives by means of microtensile bond test. Materials and Methods: The flat dentin surfaces of the extracted human molars were prepared. Each surface was treated with either two self-etching adhesive systems (Clea...

The increasing use of composite materials has led to a greater demand for efficient curing cycles to reduce costs and speed up production cycles in manufacturing. One method to achieve this goal is in-line cure monitoring to determine the exact curing time. This article proposes a novel method through which to monitor the curing process inside closed tools by employing ultrasonic spectroscopy. ...

OBJECTIVES To determine the micro-hardness profile of two dual cure resin cements (RelyX-U100, 3M-eSPe and Panavia F 2.0, Kuraray) used for cementing fiberre inforced resin posts (Fibrekor-Jeneric Pentron) under three different curing protocols and two water storage times. MATERIAL AND METHODS Sixty 16 mm long bovine incisor roots were endodontically treated and prepared for cementation of th...

statement of problem: the degree of conversion depends on the material composition, light source properties, distance from light source, light intensity, curing time, and other factors such as shade and translucency. objectives: in the present study, we evaluated the effects of different light- curing modes and shades of methacrylate and silorane-based resin composites on the degree of conversi...

The literature describes transillumination as a means of curing orthodontic light-cured composite adhesive. The literature also recommends a 2 to 3 times increase in light exposure time when light curing using transillumination. The purpose of this study was to determine the transmittance of the curing light through human enamel and the effect of transillumination on the bond strength of orthod...

The concentrations of Ca, S, Al, Si, Na, and K in the pore solutions of ordinary Portland cement and white Portland cement pastes were measured during the first 28 d of curing at temperatures ranging from 5–50 jC. Saturation indices with respect to solid phases known to form in cement paste were calculated from a thermodynamic analysis of the elemental concentrations. Calculated saturation leve...

Prediction of compressive strength of concrete is very useful for economic constructions. The compressive strength can be estimated after 28 days of casting the specimen cubes or may be predicted based on the quantum and quality of ingredients used in making the concrete. When the first one requires a 28-day time, the second one does have problem of accuracy. Hence, a hybrid model is proposed i...