| abstract |
1316129 Opal glass compositions for dental cement mixes NATIONAL RESEARCH DEVELOPMENT CORP 2 Dec 1970 [15 Dec 1969] 61041/69 Heading C1M [Also in Division C3] A surgical cement pack comprises as one component a fluoroaluminosilicate glass powder having either (a) a weight ratio of SiO 2 : Al 2 O 3 of 1À5-2À0 and a weight ratio of F: Al 2 O 3 of 0À6-2À5 or (b) a weight ratio of SiO 2 : Al 2 O 3 of 0À5-1À5 and a weight ratio of F: Al 2 O 3 of 0À25-2À0, and as another component a surgically acceptable water soluble poly-(carboxylic acid) having a relative viscosity of 1À05-2À00. The invention also relates to a novel fluoroaluminosilicate glass powder suitable for use in a surgical cement composition having (a) a weight ratio of SiO 2 : Al 2 O 3 of 1À6-1À9 and a weight ratio of F: Al 2 O 3 of 0À6-2À5, (b) a weight ratio of SiO 2 : Al 2 O 3 of 1À5-2À0 and a weight ratio of F: Al 2 O 3 of 1À05-1À5, or (c) a weight ratio of SiO 2 : Al 2 O 3 of 0À75-1À0 and a weight ratio of F: Al 2 O 3 of 0À25-2À0. The fluoroaluminosilicate glasses may be prepared by fusing mixtures of SiO 2 , Al 2 O 3 and CaF 2 optionally together with AlF 3 , AlPO 4 and Na 3 AlF 6 . Numerous examples of suitable fusing mixtures are specified. |