title: Initial flow of tissue conditioners--influence of composition and structure on gelation.
abstract: The effects of the molecular weight of polymer powders, the ethyl alcohol content of the liquids, the type of plasticizer and the polymer powder/liquid ratio on viscoelastic properties during gelation of tissue conditioners were studied with an oscillating rheometer. The results showed that: (i) The gelation time decreased exponentially with increases in molecular weight of the polymer powder and with powder/liquid ratio. There were linear relationships between the log of gelation time, and both the molecular weight of the polymer powder and the powder/liquid ratio. (ii) In general, gelation time decreased exponentially with increases in ethyl alcohol content. However, the relationship between the log of the gelation time and ethyl alcohol content fitted a second-order polynomial. (iii) The type of plasticizer affected gelation time. The order of gelation times was: benzyl benzoate < dibutyl phthalate < butyl phthalyl butyl glycolate. The initial flow of tissue conditioners could be controlled over a wide range by varying the molecular weight of the polymer powders, the ethyl alcohol content, the powder/liquid ratio and the type of plasticizer.
authors: Department of Prosthetic Dentistry, Hiroshima University School of Dentistry, Japan.
authors: H
authors: H
authors: Murata
authors: H
authors: H
authors: Iwanaga
authors: N
authors: N
authors: Shigeto
authors: T
authors: T
authors: Hamada
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001565:Benzoates / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003822:Denture Liners; D003993:Dibutyl Phthalate / Q000031:analogs & derivatives / Q000737:chemistry; D000431:Ethanol; D005782:Gels; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry*; D010795:Phthalic Acids / Q000737:chemistry; D010968:Plasticizers / Q000737:chemistry*; D012044:Regression Analysis; D012212:Rheology / Q000295:instrumentation; D013997:Time Factors; D014016:Tissue Conditioning, Dental; D014783:Viscosity
chemical_list: D000180:Acrylic Resins; D001565:Benzoates; D003764:Dental Materials; D005782:Gels; D008689:Methacrylates; D008768:Methylmethacrylates; D010795:Phthalic Acids; D010968:Plasticizers; C073909:GC Soft-Liner; C069456:Hydro-Cast dental tissue conditioner; C043685:Coe Comfort; D003993:Dibutyl Phthalate; D000431:Ethanol; C048569:butyl phthalyl butyl glycolate; C009931:poly(ethylmethacrylate); C006723:benzyl benzoate