Disclosed are biodegradable glass substrates that are useful as functional elements of solid-state devices. In particular, biodegradable glass substrates having a rapidly degradable glass and a slowly degradable glass provide a structural platform that completely dissolves following a desired operational lifetime of devices such as implanted electronic devices, implanted sensor devices, and optical fibers.

Apparatus and methods for forming melt-formed fibres and melt-formed biosoluble fibers are disclosed. The apparatus comprises a spinning head comprising one or more rotors; a plurality of nozzles or slots disposed around at least part of the one or more rotors; a conveyor; and a barrier between the spinning head and the conveyor.

A glass based fibrous filler having bioactive particles such as hydroxyapatite deposited on a surface of glass fibers. Methods of preparing the fibrous filler are specified. A resin composite containing a polymerizable system reinforced with the fibrous filler, as well as a biomedical restoration based on the cured resin composite are also provided.

A sol is provided for the production of inorganic fibres comprising precursors for aluminium oxide, silicon oxide, strontium oxide, wherein the precursors are present in proportions suitable to yield inorganic fibres having a composition comprising: 70Al.sub.2O.sub.380 wt %; 10SiO.sub.220 wt %; 10SrO20 wt % wherein the sum of Al.sub.2O.sub.3, SiO.sub.2 and SrO is at least 95 wt %.

Mineral fibers that exhibit a chemical composition comprising the following constituents, as percentages by weight: TABLE-US-00001 SiO.sub.2 57.0 to 60.0%, CaO 25.0 to 30.0%, MgO >8.0 to 10.0%, B.sub.2O.sub.3 2.5 to 6.0%, R.sub.2O up to 2.5% Al.sub.2O.sub.3 0 to 2.0%, and an R.sub.2O/B.sub.2O.sub.3 molar ratio of 0.20 to 0.60.

Mineral fibers that exhibit a chemical composition comprising the following constituents, as percentages by weight:

TABLE-US-00001 SiO.sub.2 57.0 to 60.0%, CaO 25.0 to 30.0%, MgO >8.0 to 10.0%, B.sub.2O.sub.3 2.5 to 6.0%, R.sub.2O up to 2.5% Al.sub.2O.sub.3 0 to 2.0%,

and an R.sub.2O/B.sub.2O.sub.3 molar ratio of 0.20 to 0.60.

A glass based fibrous filler having bioactive particles such as hydroxyapatite deposited on a surface of glass fibers. Methods of preparing the fibrous filler are specified. A resin composite containing a polymerizable system reinforced with the fibrous filler, as well as a biomedical restoration based on the cured resin composite are also provided.

A sol is provided for the production of inorganic fibres comprising precursors for aluminium oxide, silicon oxide, strontium oxide, wherein the precursors are present in proportions suitable to yield inorganic fibres having a composition comprising:70Al.sub.2O.sub.380 wt %; 10SiO.sub.220 wt %; 10SrO20 wt % wherein the sum of Al.sub.2O.sub.3, SiO.sub.2 and SrO is at least 95 wt %.

The present invention relates Inorganic fibres having a composition comprising: 61.0 to 70.8 wt % SiO.sub.2; 27.0 to 38.9 wt % CaO; 0.10 to 2.0 wt % MgO; and optionally, an amount of other components providing a balance up to 100 wt %. A sum of SiO.sub.2 and CaO is greater than or equal to 97.8 wt % and wherein the amount of the other components, when present, comprise no more than 0.80 wt % Al.sub.2O.sub.3.

A bioactive glass composition including: 50 to 70% SiO.sub.2; 0.1 to 10% Al.sub.2O.sub.3, 5 to 30% Na.sub.2O, 0.1 to 15% K.sub.2O, 0.1 to 15% MgO, 0.1 to 20% CaO, and 5 to 10% P.sub.2O.sub.5, based on a 100 wt % of the composition. Also disclosed is a method of making the bioactive glass composition.