title: The role of glass composition in the behaviour of glass acetic acid and glass lactic acid cements.
abstract: Cements have recently been described, made from glass ionomer glass reacted with acetic and lactic acid instead of polymeric carboxylic acid. From their behaviour a theory relating to a possible secondary setting mechanism of glass ionomer has been adduced. However, only one glass (G338) was used throughout. In this study a much simpler glass ionomer glass (MP4) was compared with G338. This produced very different results. With acetic acid G338 formed cement which became resistant to water over a period of hours, as previously reported, MP4 formed cement which was never stable to water. With lactic acid G338 behaved similarly to G338 with acetic acid, again as reported, but MP4 produced a cement which was completely resistant to water at early exposure and unusually became slightly less resistant if exposure was delayed for 6 h or more. These findings indicate that the theories relating to secondary setting in glass ionomer maturation may need revision.
authors.affiliation: Department of Biomaterials in Relation to Dentistry, Barts and London School of Medicine and Dentistry, Queen Mary University of London, Mile End, London, UK. s.shahid@qmul.ac.uk
authors.forename: Saroash
authors.initials: S
authors.lastname: Shahid
authors.forename: R W
authors.initials: RW
authors.lastname: Billington
authors.forename: G J
authors.initials: GJ
authors.lastname: Pearson
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D001672:Biocompatible Materials; D003738:Dental Cements / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001672:Biocompatible Materials; D003738:Dental Cements; D019344:Lactic Acid; D019342:Acetic Acid