Comparison in in-vivo response between a bioactive glass and a non-bioactive glass

The authors report on the in-vivo comparison, in the rabbit, between the re sponse to a bioactive glass and the response to a non-bioactive glass. Impl ants have been performed in muscle and bone. Two different glasses were inv estigated, namely B01 and I02. B01 is a glass designed to be degradable and resorbable and has a percentual molar composition of: SiO2 49.6%; P2O5 2.7 %; CaO+MgO+Na2O+K2O+Al2O3 47.7% with a 1 : 1 CaO/Na2O ratio. I02 is a sodiu m-calcium-silicate non-resorbable glass lacking P2O5 and has a percentual m olar composition of: SiO2 70.7%; CaO+MgO+Na2O+K2O+Al2O3 29.3%. In-vivo test s were planned as: (a) intramuscular implants of glass cylinders in the rec tus femoris and retrievals took place at 2, 16 and 43 weeks; (b) intraosseu s implants of glass cylinders in the distal femural canal and retrievals to ok place at 8 and 43 weeks. Histology and light microscopy analysis followe d. Bioactive degradable glass elicits a favorable response both in muscle a nd bone; a gradual degradation process leads to disruption and partial reso rption of the material and a tight apposition is promoted with the newly fo rmed bone. The non-bioactive sodium-calcium-silicate glass (named I02) may elicit, like the bioactive degradable B01, a favorable response which is ch aracterized by the absence of inflammatory or other adverse reactions; anyw ay it does not change its structure at an optical microscopic level and it does not promote any tight apposition with bone. (C) 2000 Kluwer Academic P ublishers.