The aim of this study was to evaluate the ability to resist disinfection of a polymicrobial association contaminating the surface of dental impressions obtained with two different elastomers: a polyether (Impregum) and an addition-polymerized silicone (Elite). Impressions were contaminated with a mixture of three biofilm-forming microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa and ...

Medical polyurethanes have shown good bio-stability and mechanical properties and have been used as coating for implantable medical devices. However, despite their excellent properties, they are relatively permeable to liquid water and water vapour which is a drawback for electronic implant encapsulation. In this study polyether polyurethanes with different soft segment molecular weights were m...

W hen preparing a single-unit crown, or multiple unit bridge, dentists inevitably follow a similar routine. The prepared tooth/ teeth are impressed in a good quality impression material such as a polyether, or the most widely used impression material, an addition silicone vinyl polysiloxane (VPS),1 which accounts for 95% of the impressions sent to the dental laboratory.2 The impressions are tak...

Our previous studies have demonstrated that surfaceactive copolymers of Pluronic® surfactants and tertiary amino polycations such as poly (2-dimethylaminoethyl methacrylate) (PDMA) possess an enhanced DNA transfection efficiency compared to PDMA homopolymers. In order to understand the mechanism of such action, we conducted model studies of the interaction of polymer with phospholipid vesicles ...

  Despite promising results observed using silicone rubber chamber, no previous comprehensive work was performed on behavior of the conduit. Present study aimed at further functional, histomorphometrical and immunohistochemical assessment of nerve regeneration in the same animal along a 10-mm rat sciatic nerve gap. Fifty- four male Wistar rats were divided into three experimental groups (n = 1...

Highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (N) or of copolymerizing them with ethene (E) or propene (P). The polymers obtained show exciting structures and properties. E-N copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their micr...

Permeability of block copolymers is an important feature for a broad range of applications including packaging, bio-materials (e.g. for controlled release or encapsulating membranes), barrier materials, high performance impermeable breathable clothing and membrane separation processes. This paper reviews the literature on permeability of block copolymers to pure or mixed vapors and liquids for ...

4-chloromethyl styrene homopolymer and its copolymers with styrene were prepared from their corresponding 4-chloromethyl styrene and styrene monomers at 1:0, 1:1, 1:3 and 1:5 mole ratios. these homo- and copolymerswere synthesized by radical polymerization in presence of aibn as initiator and dry toluene as solvent. then, chloromethyl groups were converted into azidomethyl groups on the homo- a...