statement of problem: accurate impressions are one of the most critical factors in achieving acceptable restorations. when pouring the impressions of implant supported restorations, soft materials like silicone and polyether are used to reconstruct the gingival form around the implants. to the best of our knowledge, no study has been conducted on the comparison of the accuracy of these soft mat...

Two sets of segmented polyurethane (PU) elastomers were prepared from 4,4!-methylenebis(phenyl isocyanate) (MDI), 1,4-butanediol (BD) and a polyester or a polyether polyol, respectively. The molecular mass of both polyols was 1000 g/mol. The stoichiometric ratio of isocyanate and hydroxyl groups was 1 and the polyol/total diol ratio changed from 0 to 1 in 0.1 steps. One step bulk polymerization...

AIM This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. MATERIALS AND METHODS Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were st...

Polyether antibiotics are a large class of microbial secondary metabolites generally produced by soil actinomycetes of the genus Streptomyces'). Intensive search for new polyether antibiotics has in recent years revealed that other genera of streptomycetes also produce these antibiotics. Laidlomycin is produced by Streptoverticillum eurocidium'). Cationomycin'), antibiotics CP-47,433 and CP-47,...

Turbine oil plays an important role in supporting optimal steam turbine performance. Some additives in turbine oil can cause emulsification when the oil is contaminated by water, so demulsibility is a very important property of the steam turbine oil. In order to improve the demulsibility of steam turbine oil, two kinds of polyether-silicone comb copolymers are synthesized and used as steam turb...

BACKGROUND Ciguatera is a circumtropical disease produced by polyether sodium channel toxins (ciguatoxins) that enter the marine food chain and accumulate in otherwise edible fish. Ciguatoxins, as well as potent water-soluble polyethers known as maitotoxins, are produced by certain dinoflagellate species in the genus Gambierdiscus and Fukuyoa spp. in the Pacific but little is known of the poten...

OBJECTIVE The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. MATERIALS AND METHODS Polyether impression material samples...

Thermoplastic polyamide elastomer (PAE) [also PEBA: polyether block amide] is one of the most recently developed of the thermoplastic elastomers: a multiblock polymer with polyamide hard segments, it uses longchain polyether diol or polyester diol of low Tg for its soft segments. Polyamide 6 or polyamide 12 (PA12) is the main polyamide component used, while the soft segments are mostly provided...

AIM To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test. METHODOLOGY Human gingival fibroblasts were cultured ex vivo. Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 degrees C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluate...

Objective. To investigate the accuracy of dies obtained from single-step and 2-step double-mix impressions. Material and Methods. Impressions (n = 10) of a stainless steel die simulating a complete crown preparation were performed using a polyether (Impregum Soft Heavy and Light body) and a vinyl polysiloxane (Perfectim Blue Velvet and Flexi-Velvet) in two consistencies, in one or two (without ...