| 摘要 |
1334685 Dental powder LABORATOIRE SPAD 14 Oct 1970 [20 Nov 1969] 48892/70 Heading C3N [Also in Division C4] Colophony, which has been modified by subjecting a mixture of colophony, zinc oxide and/or lead oxide and 1-5% wt. based on the colophony of trioxymethylene to an elevated temperature in the presence of air, can be used in making pastes with eugenol which set in less than 10 minutes, for use in filling root ducts of teeth. At least one of hydrated Al 2 O 3 , calcined Al 2 O 3 and barium sulphate may be added to the mixture prior to the modification treatment. Preferred mixtures comprise 25-50% wt. lead oxide or 100-400% wt. zinc oxide. Another preferred mixture which is subjected to the modification treatment comprises 10-15 g. hydrated Al 2 O 3 ; 4-8 g. calcined Al 2 O 3 ; 50- 60 g. ZnO; 4-8 g. red lead oxide; 15-30 g. colophony, and at least 0À2 g. trioxymethylene up to 5% wt. based on the colophony. |
