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...

Dragon's blood is a deep red resin which has been used for centuries by many cultures and much prized for it's rarity, depth of colour and alchemical associations. The original source of dragon's blood resin is believed to be Dracaena cinnabari from Socotra in Africa, but since mediaeval times there have been several alternatives from different geographical locations from the Canary Islands to ...

The role of separations in inorganic analysis is discussed and the advantages of various chromatographic techniques are stressed. Major separation methods include solvent extraction, column extraction chromatography, gas chromatography of volatile metal chelates, ionexchange chromatography, and column chromatography employing chelating resins and non-ionic sorptive resins. The use of each of th...

UNLABELLED The longevity and durability of composite resins are influenced by the actions of water, saliva, drinks, food and features of the oral environment. OBJECTIVE The aim of this study was to evaluate the effect of mouthwashes containing alcohol on the surface hardness, sorption and solubility of composite resins. METHODS Disc-shaped specimens were prepared with two composite resins Z...

OBJECTIVE This study evaluated the fracture toughness (FT) of denture base and autopolymerizing reline resins, with and without thermocycling (T). MATERIAL AND METHODS Specimens of each material (denture base acrylic resin - Lucitone 550 - L; autopolymerizing reline resins - Ufi Gel Hard-UH, Tokuyama Rebase II-TR, New Truliner-NT and Kooliner-K), were produced, notched and divided into two gr...

STATEMENT OF PROBLEM Provisional prostheses are subject to flexure under function. Selection of the appropriate material for their fabrication is difficult given the limited evidence-based information on the flexural strength of provisional resins. PURPOSE This study compared the flexural strength of 5 methacrylate-based resins and 8 bis-acryl resins used to fabricate provisional crowns and f...

In a previous report (1), the differences in the carbon number of the lower fatty acids contained in cutaneous secretions such as axillary sweat, smegma, and dandruff, were considered as factors responsible for the difference in odor between osmidrotic and non-osmidrotic subjects. Besides these there are ammonia constituents and volatile salts (trimethylamine, methylamine) which may take part i...

One method of reducing styrene emissions from vinyl ester (VE) and unsaturated polyester resins (UPE) is to replace some or all of the styrene with fatty acid-based monomers. Methacrylated fatty acid (MFA) monomers are ideal candidates because they are inexpensive, have low volatilities, and free-radically polymerize with vinyl ester. The viscosity of VE resins using these fatty acid monomers r...

Extraction of boron from aqueous solutions using selective resins is important in a variety of applications including desalination, ultrapure water production, and nuclear power generation. Today's commercial boron-selective resins are exclusively prepared by functionalization of styrene-divinylbenzene (STY-DVB) beads with N-methylglucamine to produce resins with boron-chelating groups. However...

This experimental study investigates the bioactive potential of filaments produced via hot melt extrusion (HME) and intended for fused deposition modeling (FDM) 3D printing purposes. The oleo-gum-resins from benzoin, myrrha, and olibanum in pure state and also charged with 10% of metal oxide nanoparticles, TiO2, P25, Cu2O, and MoO3, were characterized by ultraviolet-visible (UV-Vis) and Fourier...