| 摘要 |
1297303 Artificial teeth &c RESEARCH CORP 27 Feb 1970 [10 March 1969] 9501/70 Heading A5R [Also in Division C3] Compositions comprising a mixture of an acrylic polymer, e.g. polymethyl methacrylate, and powdered anorganic bone or cartilage, the latter not exceeding 30% by weight of the mixture are useful for forming artificial dental implants, for use as a coating material for metal implants and prostheses, and as human tissue or bone substitute, e.g. to fill defects or holes in the brain, skull &c. The compositions enable satisfactory fibrous interlock with bone or tissue to be achieved. The compositions may also include a foaming agent to provide additional porosity and, for dental implants, may also contain grated natural tooth (taken from the root so as to exclude any enamel). In a specific embodiment, Figs. 1 and 4 show an artificial tooth crown 10 mounted in a gum 12 by means of metallic pins or struts 14 arranged in a tripod formation. Each pin, as shown in Figs. 5 and 6, comprises an enlarged point at the front end 16, an enlarged cylindrical rear 18 and a reduced shaft portion 20 extending between front and rear. The shaft portion is provided with a plurality of notches 22 for promoting a strong bond between the shaft portion and coating 24 which is formed from the composition of the invention and is substantially flush with portions 16 and 18. The pins are preferably made of a chrome/ cobalt/molybdenum alloy. It is possible, alternatively, to completely coat the pins and dispense with the reduced shaft portion. |
