Glass phosphonate cement

In a later development of glass ionomer cements, glass phosphonate cements were introduced, in which the glass powder is combined with polyviityl phosphonic acid. These cements exhibit very favorable setting and working characteristics, and attain final compressive strengths of up to 200 MPa. 

H. M. Anstice, J.W. Nicholson, Investigation of the post-hardening reaction in glass-ionomer cements based on poly(vinyl phosphonic acid), J. Mater. Sci. Mater. Med. 6 (1995) 420-423. 

The polyelectrolytes used in practical glass-ionomers are polyaUcenoic acids, and two such substances are employed as the main polymer in these cements, namely the homopolymer poly(acrylic acid) and the 2 1 copolymer of acrylic acid and maleic acid. In addition, poly(vinyl phosphonic acid) has been studied as a potential cement former, but its practical use is restricted to a single brand, where it is used in a mixture with poly(acrylic acid) and effectively acts as a setting rate modifier. 

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