BACKGROUND Bisphenol A (BPA) is an endocrine disruptor with potential toxicity. Composite resins may not contain pure BPA, but its derivatives are widely used. Several studies found doses of BPA or its derivatives in saliva or urine of patients after composite resin placement. OBJECTIVE The aims of this study were to establish an exhaustive list of composite resins marketed in Europe and thei...

Computer-aided design and computer-aided manufacturing (CAD/CAM) denture base manufacturers claim to produce their resin pucks under high heat and pressure. Therefore, CAD/CAM dentures are assumed to have enhanced mechanical properties and, as a result, are often produced with lower denture base thicknesses than conventional, manually fabricated dentures. The aim of this study was to investigat...

Pyrolysis-gas chromatography-mass spectrometry (MS) was used to identify the major organic products produced by pyrolysis of three foundry sand resins: (i) Novolac and (ii) phenolic urethane (PU) (both phenol-formaldehyde based resins) and (iii) furan (furfuryl alcohol based resin). These resins are used in the metal casting industry as a "sand binder" for making cores (used to produce cavities...

Dental modeling resins have been developed for use in areas where highly precise resin structures are needed. The manufacturers claim that these polymethyl methacrylate/methyl methacrylate (PMMA/MMA) resins show little or no shrinkage after polymerization. This study examined the polymerization shrinkage of five dental modeling resins as well as one temporary PMMA/MMA resin (control). The morph...

This work describes the development and characterization of mechanical flexible epoxy resins based on epoxidized vegetable oils (EVO) sebacic acid. Different oil types (linseed oil, hempseed soybean oil) with varying equivalent weight (EEW) were used. Formulation processing parameters systematically optimized by differential scanning calorimetry Fourier-transform infrared spectroscopy. The effe...

BACKGROUND Natural resins were frequently employed as adhesives or as components of oleo-resinous media in paintings in the past. The identification of vegetable resins is still an open problem. The aim of this paper is to analyze by GC-MS some vegetable resins frequently employed in paintings, such as Venice turpentine, dammar, copal, elemi in order to identify their main component in raw and ...

The intimate marginal adaptation of composite resins is considered to be the most important requisite, and this is strongly influenced by polymerization shrinkage, thermal expansion or mechanical properties of the resins. The highly loaded composite resins, developed recently have yielded good results on thermal expansion and mechanical properties. Consequently, little attention has been paid t...

Ion-exclusion chromatography (IEC) has been widely used in the separation of carboxylic acids, finding applications in the analysis of food and beverages, pharmaceuticals, biological samples, and acid rain samples.' The retention mechanism of carboxylic acids in ion-exclusion chromatography has also been investigated in many studies, and the factors which affect retention can be divided into th...