Glass, Phillip

Phetharbital [357-67-5] pH Glass electrode Philips 2P Process Phillips catalysts... 

Crystd from hot water (4mL/g at 65°), then dried in a vacuum desiccator over CaS04. Phillips and Taylor [J Chem Soc 4242 7962] cooled an aqueous solution of KMn04, saturated at 60°, to room temperature in the dark, and filtered through a No.4 porosity sintered-glass filter funnel. The solution was allowed to evaporate in air in the dark for 12h, and the supernatant liquid was decanted from the crystals, which were dried as quickly as possible with filter paper. 

The first commercial grades were introduced by Phillips Petroleum in 1968 under the trade name Ryton. These were of two types, a thermoplastic branched polymer of very high viscosity which was processed by PTFE-type processes and an initially linear polymer which could be processed by compression moulding, including laminating with glass fibre, and which was subsequently oxidatively cross-linked. 

However, restorations made from this material could not be polished and were aesthetically very poor. Simmonds (1983) has pursued this idea, and a material has been placed on the market. But according to Moore, Swartz Phillips (1985) such cements have less resistance to abrasion than a simple glass polyalkenoate cement. 

Hinoura, K., Moore, B. K. Phillips, R. W. (1987). Bonding agent influence on glass ionomer-composite resin. Journal of the American Dental Association,... 

Swartz, M. L., Phillips, R. W. Clark, H. E. (1984). Long-term F release from glass ionomer cements. Journal of Dental Research, 63, 158-60. 

Dental silicate cement was once the most favoured of all anterior (front) tooth filling materials. Indeed, it was the only material available for the important task of aesthetic restoration from the early 1900s to the mid 1950s, when the not very successful simple acrylic resins made their appearance (Phillips, 1975). In the mid sixties there were some 40 brands available (Wilson, 1969) and Wilson et al. (1972) examined some 17 of these. Since that time the use of the cement has declined sharply. It is rarely used and today only two or three major brands are on the market. The reason for this dramatic decline after some 50 years of dominance is closely linked with the coming of modern aesthetic materials the composite resin from the mid 1960s onwards (Bowen, 1962), and the glass-ionomer cement (Wilson Kent, 1971) from the mid 1970s. 

Despite the failing of the dental silicate cement under acid conditions it is more resistant to acid attack than all other dental cements with the notable exception of the glass polyalkenoate cement (Norman, Swartz Phillips, 1959 Walls, McCabe Murray, 1985 Beech Bandyopadhyay, 1983 Kuhn, Setchell Teo, 1984 Wilson et al., 1986a). These studies have been confirmed by in vivo observations (Norman et al., 1969). A clinical study carried out by Robinson (1971) over many years showed that when carefully prepared and placed, the dental silicate cement was capable of giving good performance. Many of the failures of this material must be attributed to faulty preparation. 

Silicophosphate cement acts as an agent for the sustained release of fluoride, although different cements behave very differently (Wilson, Crisp Lewis, 1982). Silicophosphate cement has a disability in the mouth similar to that of dental silicate cement. It is less resistant to oral fluids than glass polyalkenoate cement, but more resistant than all other dental cements, as is shown by both in vivo studies (Norman et al., 1969 Ritcher Ueno, 1975 Clark, Phillips Norman, 1977 Mitchem Gronas, 1978 ... 

Phillips, C. J., 1948, Glass The Miracle Maker, 2nd Edn London, Pitmaa... 

Harris B., Morley J. and Phillips D.C. (1975). Fracture mechanisms in glass-reinforced plastics. J. Mater. Sci. 10, 2050-2061. 

Carroll, S. A., Bourcier, W. L. Phillips, B. L. 1994. Surface chemistry and durability of borosilicate glass. In Barkatt, A. Van Konynenbourg, R. A. (eds) Scientific Basis for Nuclear Waste Management XVII. Materials Research Society Symposia Proceedings, 333, 533-540. 

Phillips, D.C., Interfacial bonding and the toughness of carbon fibre reinforced glass and glass-ceramics , J. Mat. Sci., 9, 1847-1854 (1974). 

Sambell, R.A.J., Briggs, A., Phillips, D.C. and Bowen, D.H., (1972a), Carbon fibre composites with ceramic and glass matrices, Part I. Discontinuous fibres , J. Mater. Sci., 7, 663-675. 

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