Abstract: A process is provided for the production of dicalcium phosphate form a phosphate source material in which a solution of phosphoric acid is produced by the action of a suitable mineral acid, generally sulphuric acid, on a phosphate source material. Calcium fluoride is precipitated at a pH of between 3.5 and 4.5 followed by hydrolyzing the solution by diluting it with water to a ratio of approximately 1:7 to about 1:10 monocalcium phosphate to water at a temperature of approximately 40 degrees Centigrade to form a primary precipitate containing substantially all of the fluoride present as CaF2 together with some dicalcium phosphate and a primary calcium and phosphate containing solution. The primary precipitate is dissolved, the pH adjusted to form 3.5 to 4.5 and the hydrolyzation repeated to form a secondary precipitate containing substantially all of the fluoride present as CaF2 together with some dicalcium phosphate and a secondary calcium and phosphate containing solution.

Abstract: Methods of making porous calcium phosphate bone replacement materials are discussed.

Abstract: A bone replacement material and therapy comprises the combination of calcium phosphate compounds and two or more soluble fillers in the form of fibers, mesh or other materials which have the dual functions of reinforcing an in vivo implant while dissolving at a programmed rate to form macropores capable of receiving natural bone ingrowth.

Abstract: A zirconium phosphate compound having a Zr:P ratio of from about 1.80-2.0 to 1, which compound's H-form exhibits a single peak at ?13.7±0.5 ppm in the 31P NMR spectra. The compound is useful as a catalyst, catalyst support and ion exchange media having a high affinity for cobalt and nickel ions.

Abstract: A bone replacement material and therapy comprises the combination of calcium phosphate compounds and two or more soluble fillers in the form of fibers, mesh or other materials which have the dual functions of reinforcing an in vivo implant while dissolving at a programmed rate to form macropores capable of receiving natural bone ingrowth.

Abstract: The invention relates to zirconium phosphate of H form which is characterized by a 31P NMR spectra comprising peaks at ?4.7 ppm, ?12.8 ppm and ?17.0 ppm (all peaks being in a range of ±0.5 ppm). Also featured is a Na form of the material. The zirconium phosphate material is characterized by a unique surface area, pore size distribution and surface morphology, as well as by an affinity for NH4+ ions and moisture insensitivity. Also featured is hafnium phosphate characterized by moisture insensitivity. The zirconium phosphate may be amorphous and possess a framework-type structure. The inventive method of making zirconium phosphate includes the steps of heating an aqueous mixture including a zirconium compound and a phosphorous-containing reagent at a temperature of at least 120° C. to form a reaction product, and treating the reaction product with acid at a temperature of at least 60° C.

Abstract: The invention relates a process for producing an alkali metal nitrate and an alkali metal phosphate in the same process from a phosphate raw material and a nitrate raw material comprising the steps of: a) reacting the phosphate raw material with the nitrate raw material to provide an aqueous nitrophosphate feed, optionally followed by the separation of solid material, b) introducing the aqueous nitrophosphate feed into a first ion exchange step comprising an alkali metal-loaded cationic exchange resin for exchanging cations present in the feed with alkali metal ions present on the resin to obtain a stream enriched in alkali metal ions, c) subjecting the stream from step (b) to a first crystallization under such conditions that an alkali metal nitrate is crystallized and separating the crystallized alkali metal nitrate from the mother liquor, d) introducing the mother liquor from step (c) into a second ion exchange step comprising an alkali metal-loaded cationic exchange resin for exchanging cations present

Abstract: The invention relates to a hydroxylapatite material containing phosphate wherein the microporous structure of algae hard-tissue raw material is retained in the end product and which can be obtained by reacting an organic compound devoid of algae hard-tissue in an alkaline aqueous phosphate solution by adding magnesium ions at an elevated temperature. The invention also relates to a method for the production of said hydroxylapatite material containing tricalcium phosphate, which is characterized in that it is especially well resorbed in the body, is especially suitable as a bone substitute material or as a carrier material for active ingredients. Said material can also be used as a filter material.

Abstract: A method of making sodium zirconium carbonate is described which involves forming a mixture of zirconium oxychloride with soda ash and then heating at a sufficient temperature and for a sufficient time to form the sodium zirconium carbonate. Subsequent washing and filtration steps can further form parts of this process. A novel sodium zirconium carbonate is further described which contains from about 2 wt % to about 5 wt % Na+; from about 44 wt % to about 50 wt % ZrO2; from about 12 wt % to about 18 wt % CO32−; and from about 32 wt % to about 35 wt % H2O. Methods of making zirconium basic carbonate are further described which involve titrating an aqueous slurry of sodium zirconium carbonate to a pH of from about 3.5 to about 4.0 with an acidic agent wherein the sodium zirconium carbonate has a moisture content of from about 15% to about 25% LOD in solid form. The process further involves washing the aqueous slurry containing the formed zirconium basic carbonate with water.

Abstract: The present invention relates to a method for preparation of the supersaturated calcium and phosphate ions solution and a method for preparation of the thin film of calcium phosphate crystal on solid surface by using the said solution. Particularly, the lowered temperature and/or the use of suitable buffer system inhibit the nucleation of calcium phosphate in aqueous solution, and thereby highly supersaturated calcium and phosphate ions solution can be prepared. And the thin film of calcium phosphate crystal on solid surface can be prepared with rapidity and good quality of high reactivity and low crystallinity by using the said solution. Also the thin film of calcium phosphate crystal prepared according to the present invention has biocompatibility and can be applied as biomaterials.

Abstract: A silver ion sequester and release agent is described which comprises a silver ion exchangeable material of the formula: M(H1−x−yAgxM′yPO4)2.nH2O; where M is Zr, Ti, Sn, Ge or Hf or any combination thereof; M′ is an Alkali or alkaline earth metal; x is a number from 0.10 to 0.80; y is a number from 0.15 to 0.85; (x+y) is a number from 0.25 to 0.95; and n is a rational number between 0 and 10. Processes for preparing such silver ion sequester and release agent material are also described comprising combining in an aqueous medium a crystalline or amorphous metal hydrogen phosphate ion exchange host material of the formula M(HPO4)2.nH2O with less than 2 molar equivalents of silver ions relative to the amount of ion exchange host material such that silver ions are exchanged for protons in the host material, and adding a base compound to the aqueous medium to achieve a pH of at least 4.4 and sequester at least 95% of the combined silver ions into the host material.

Abstract: Process for the preparation of a vanadium phosphate catalyst comprising treatment of a vanadium compound with formic acid, water and a phosphorus compound.

Abstract: The present invention is directed to methods for preparing hydrous iron oxide spherules, hydrous iron oxide gels such as gel slabs, films, capillary and electrophoresis gels, iron monohydrogen phosphate spherules, hydrous iron oxide spherules having suspendable particles homogeneously embedded within to form composite sorbents and catalysts, iron monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent, iron oxide spherules having suspendable particles homogeneously embedded within to form a composite of hydrous iron oxide fiber materials, iron oxide fiber materials, hydrous iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, iron oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, dielectric spherules of barium, strontium, and lead ferrites and mixtures thereof, and composite catalytic spherules of barium or s

Abstract: A process for the preparation of a single phase magnesium- and carbonate-substituted hydroxyapatite composition, which process comprises the steps of (i) preparing an aqueous solution containing CO32− and PO43− ions in the substantial absence of cations other than H+ ions; (ii) mixing the solution from step (i) with an aqueous calcium- and magnesium-containing solution or suspension; and (iii) collecting and drying the precipitate formed in step (ii); the ratio of (Ca+Mg/P) in the calcium- and magnesium-containing solution or suspension and the phosphorus-containing solution, when mixed together, being maintained at 1.67, or above. The product of the process is novel and comprises up to 0.5% magnesium and up to 1% of carbonate substituted into the hydroxyapatite structure and which does not contain Na+ or NH4+ ions, the ratio of (Ca+Mg/P) being greater than 1.67.

Abstract: A process for the preparation of a single phase carbonate-substituted hydroxyapatite composition, which process comprises the steps of (i) preparing an aqueous solution containing Co32− and PO43− ions in the substantial absence of cations other than H+ ions: (ii) mixing the solution from step (i) with an aqueous solution or suspension of a calcium compound; and (iii) collecting and drying the precipitate formed in step (ii); the ratio of Ca/P in the calcium-containing solution or suspension and the phosphorus-containing solution, when mixed together, being maintained above 1.67. The product of the process is novel with a Ca/P molar ratio of greater than 1.67 and comprises up to 5% by weight of CO32− ions substituted in the B site or the B and A sites of the hydroxyapatite structure, with at least 50% of the CO32− ions being substituted on the B site. This product does not contain Na+ or NH4+ ions.

Abstract: The present invention provides a method of manufacturing calcium phosphate powder comprising the steps of preparing a mixed material by mixing calcium hydroxide (Ca(OH)2) powder and calcium hydrogenphosphate powder so that a molar ratio (Ca/P) of calcium to phosphor is set to a range of 1.45-1.72; conducting a mixing/milling treatment to the mixed material to cause a soft-mechanochemical compositing reaction thereby to prepare a calcium phosphate precursor; and conducting a heat treatment to thus obtained precursor at a temperature of 600° C. or more thereby to prepare calcium phosphate powder. According to the present invention, the manufacturing process is simple and the manufacturing cost can be remarkably reduced. In addition, fine calcium phosphate powder excellent in characteristics can be easily manufactured in a short time.

Abstract: A method for the conditioning of phosphoric acid containing solutions is described, wherein the solution is converted to a solid material by adding an aluminum compound. This solid material can readily be stored in disposal sites because it is not water-soluble. This method is particularly suited for the conditioning of phosphoric acid containing solutions from metal processing. An apparatus (10) for carrying out the method comprises a mixing tube (12) with a longitudinal axis (M) as well as an inlet (14) and an outlet (16). At least two liquid supply nozzles (18 and 20) opens into the mixing tube inlet (14) and, with respect to the inlet cross-sectional area of same, into a central area. Moreover, at least one gas supply nozzle (22) which is arranged radially outward of the liquid supply nozzles (18 and 22) opens into the mixing tube inlet (14). The longitudinal axis (G) of each gas supply nozzle (22) is inclined relative to the longitudinal centre axis (M) in such manner that said axes do not intersect.

Abstract: A method of manufacturing a phosphate-bonded refractory product entirely during the mixing cycle by reacting phosphoric acid and alumina derived from one or more sources of finely divided reactive alumina, for example &bgr;-alumina and/or alumina hydroxide to form a proto aluminum orthophosphate gel or paste binder in the pan of a high-intensity mixer at ambient temperatures.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like. Optionally the compositions may include proteins or serve as a depot for compositions of pharmacological interest.

Abstract: The present invention provides a synthetic silicon-substituted apatite or hydroxyapatite which comprises 0.1% to 5% by weight of silicon. The silicon-substituted apatite or hydroxyapatite may be used as a synthetic bone material for use in bone substitution, implants, fillers and cements, coatings for metallic implants, and for making hydroxyapatite-polymer composites. The silicon-substituted apatite is prepared by reacting a calcium salt or calcium hydroxide with orthophosphoric acid or a salt of orthophosphoric acid in the presence of a silicon-containing compound, the molar ratio of calcium ions to phosphorous-containing ions being from 1:0.5 to 1:0.7 and the molar ratio of calcium ions to silicon-containing ions being at least 1:0.2, whereby a precipitate of a silicon-substituted apatite is formed. On heating and/or sintering the silicon-substituted apatite at a temperature of from 500° C. to 1400° C.

Abstract: Methods comprise contacting apatite-forming-systems with partially alkylated xanthines. The methods include pharmaceutical applications of partially alkylated xanthines to mitigate the effects of hard tissue diseases. Products comprise apatite formed from apatite-forming-systems contacted with partially alkylated xanthines.

Abstract: A method of producing a ceramic material based on calcium phosphate compounds for use in dental medicine by adding a phosphate solution to a calcium salt solution, separating the precipitation formed in the reaction solution from the mother liquor, drying, crushing and sintering is characterised in that at least one orthophosphate and at least one diphosphate, each in solution, are added to the calcium salt solution, wherein the molar ratio of diphosphate to orthophosphate is in the region of 0.001 to 0.03:1, and keeps the pH-value of the reaction solution in which the precipitation is formed in the region of 7.5 to 12 until the end of the reaction.

Abstract: This invention is directed to the preparation of alloy articles consisting essentially of glass and high temperature organic thermoplastic or thermosetting polymers having working temperatures which are compatible with that of the glass and/or the precursor glass for the glass-ceramic. The glass and polymer are combined at the working temperature to form an intimate mixture; i.e., the glass and polymer are in a sufficiently fluid state to be blended together to yield a body exhibiting an essentially uniform, fine-grained microstructure wherein, desirably, there is at least partial miscibility and/or a reaction between the glass and the polymer to promote adhesion and bonding therebetween. A body is shaped from the mixture and cooled to room temperature.

Abstract: There is disclosed a novel process for preparing hemipotassium phosphate useful as an acidulant for beverages. An equimolar mixture of monopotassium phosphate and phosphoric acid is heated to a temperature above 100.degree. C. cooled with vigorous agitation whereby the liquid loses its free water and crystallizes to a relatively dry crystalline mass. When prepared by the process of this invention hemipotassium phosphate provides a dry, flowable, crystalline product which can be transported and handled easily.

Abstract: Setting times of calcium phosphate cement compositions are enhanced by the addition of phosphate or carbonate lubricant compositions. Methods for preparing the cement compositions are provided.

Abstract: A solution process for the purification of calcium hydroxide, particularly from hydrated carbide lime, which is subsequently used as a feed stock for a high-value calcium product, preferably calcium carbonate. Precipitated calcium carbonate is formed by reaction of the purified calcium hydroxide solution with carbon dioxide in a plug-flow reaction system.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like. Optionally the compositions may include proteins or serve as a depot for compositions of phrarmacological interest.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like.

Abstract: Products comprise apatite formed from apatite-forming-systems contacted with partially alkylated xanthines.

Abstract: Carbonated hydroxyapatite compositions and their preparation are described. The compositions are biologically resorbable and are prepared as flowable masses which can be administered by syringe to set in situ to serve as a support structure, filler, prosthesis or the like. Optionally the compositions may include proteins or serve as a depot for compositions of phrarmacological interest.

Abstract: Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 .mu.m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogenous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided.

Abstract: A solution process for the purification of calcium hydroxide, particularly from hydrated carbide lime, which is subsequently used as a feed stock for a high-value calcium product, preferably calcium carbonate. Precipitated calcium carbonate is formed by reaction of the purified calcium hydroxide solution with carbon dioxide in a plug-flow reaction system.

Abstract: Setting times of calcium phosphate cement compositions are enhanced by the addition of phosphate or carbonate lubricant compositions. Methods for preparing the cement compositions are provided.

Abstract: A method for the manufacture of phosphate glass comprising forming an aqueous slurry by mixing phosphoric acid, a zinc compound and other batch materials in the required proportions, heating the batch slurry to produce a molten phosphate glass that exhibits a P.sub.2 O.sub.5 /ZnO weight ratio range between about 1.2 to 2.0, and cooling the molten phosphate glass to room temperature.

Abstract: A process for producing spherical, non-porous hydroxyapatite particles having a size which does not exceed 250 microns and having a density of at least 3.00 g/cc. The process comprises agglomerating in the presence of water as the only additive hydoxyapatite powder feedstock having a purity of at least 97%, and having metallic impurities which do not exceed 500 ppm, to form hydroxyapatite particles having a size which does not exceed 350 microns. The particles are then dried and then sintered at a temperature from about 1,100.degree. C. to about 1,200.degree. C. to provide spherical, non-porous hydoxyapatite particles which do not exceed 250 microns and having a density of at least 3.00 g/cc. Such particles have a variety of medical uses, including bone replacement, implant coatings, and dental applications such as alveolar ridge augmentation, root extraction site fillings, restoration of periodontal osseous lesions, and soft tissue augmentations.

Abstract: A method for the production of condensed molasses solubles-enriched calcium phosphate includes the step of reacting, in an exothermic reaction, a predetermined amount of a calcium oxide-containing product with a predetermined amount of an aqueous solution of phosphoric acid and a predetermined amount of condensed molasses solubles to produce a reaction mixture containing calcium phosphate and condensed molasses solubles. The method, further, includes allowing the heat produced in the exothermic reaction to evaporate at least a part of the water present in the reaction mixture. The condensed molasses solubles-enriched calcium phosphate product is isolated in loose granular form and has a water content of 0-15% (mass/mass).

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calcium phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: A substantially pure hydroxyapatite filament provides the reinforcement for composite materials used for bone replacement and repair. Its biocompatibility and high strength reveal opportunities for strong, tough and biocompatible composites to replace diseased, fractured or missing areas of bone. One such opportunity is a hydroxyapatite fiber reinforced hydroxyapatite matrix composite. This composite has higher strength and toughness than sintered hydroxyapatite yet has excellent biocompatibilty and mechanical properties which can be tailored to mimic replaced bone. Methods for filament fabrication include low temperature extrusion of a precursor gel filament reinforced with hydroxyapatite whiskers, high temperature sinter-extrusion and high temperature glass filament formation followed by reconversion to hydroxyapatite by intermediate temperature heat treatment.

Abstract: Methods and compositions are provided for preparing storage stable partially neutralized acid compositions. The partially neutralized acid compositions are amenable to prolonged periods of storage. Following storage, the acids can be neutralized with a calcium neutralizing source and combined with a lubricant to form a rapidly setting calcium phosphate mineral suitable for a variety of purposes, e.g. bone replacement.

Abstract: Methods for producing a room temperature stable, phase pure .alpha.-C.sub.3 P product, and compositions derived therefrom, are provided. In the subject method, a tricalcium phosphate source is heated to a temperature sufficient to convert substantially all of said tricalcium phosphate source to a substantially phase pure .alpha.-C.sub.3 P product. The temperature of the resultant product is rapidly cooled to a temperature below about 700.degree. C., resulting in a room temperature stable, reactive .alpha.-C.sub.3 P product. The resultant .alpha.-C.sub.3 P product may be milled to provide an .alpha.-C.sub.3 P composition which may find use in the preparation of calcium phosphate cements.

Abstract: A process for enhancing the security of implantable surgical devices secured to bone tissue comprising implanting in bone tissue a surgical device with a biocompatible adhesive and/or sealant selected from the group consisting of: p1 (a) a material made from monomers of the formula:CHR.sup.1 .dbd.CX.sup.1 Y.sup.1wherein X.sup.1 and Y.sup.1 are each strong electron withdrawing groups, and R.sup.1 is hydrogen or, provided that X.sup.1 and Y.sup.1 are both cyano groups, a C.sub.1 -C.sub.4 alkyl group;(b) a semi-crystalline aliphatic poly(ester) of the formula:[--0--R.sup.11 --C(0)--].sub.y,wherein R.sup.11 is selected from the group consisting of --CR.sup.12 H--, --(CH.sub.2).sub.3 --0--, --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --, CR.sub.12 H--CH.sub.2, --(CH.sub.2).sub.4 --, --(CH.sub.2).sub.z --O--C(O)-- and --(CH.sub.2).sub.z --C(O)--CH.sub.2 --; R.sup.

Abstract: The invention includes methods and compositions relating to calcium phosphate cements, which self-harden substantially to hydroxyapatite at ambient temperature when in contact with an aqueous medium. More specifically the cements comprise a combination of one or more sparingly soluble calcium phosphates other than tetracalcium phosphate with an aqueous solution adjusted with a base to maintain a pH of about 12.5 or above and having sufficient dissolved phosphate salt to yield a solution mixture with phosphate concentration equal to or greater than about 0.2 mol/L.

Abstract: Two component, storage stable apatitic cement compositions, as well as methods for their production, are provided. The dry component of subject apatitic cements comprises basic calcium source particles at least partially coated with a partially neutralized acidic calcium phosphate. The dry component of subject compositions is prepared by combining basic calcium source particles with dissolved acidic phosphate in at least a partially aqueous medium, whereby the basic calcium source particles become partially coated with a partially neutralized acidic calcium phosphate. The reaction is terminated prior to completion of the reaction between the acidic phosphate and the basic calcium source by removing the available water from the reaction mixture. In a first mode, the subject cement may be produced by mechanically mixing an acidic phosphate source with basic calcium source particles in the presence of an aqueous solvent and stopping the reaction between the acid and base prior to completion.

Abstract: Novel aluminum phosphates, in particular amorphous aluminum phosphate powders having a BET specific surface no greater than 25 m.sup.2 /g, well suited as binders/hardeners or for the production of ceramic shaped articles, are prepared by reacting at least one aluminum compound, e.g., an aluminum oxide, hydroxide or oxyhydroxide, with phosphoric acid or an aluminum phosphate, e.g., an acid aluminum orthophosphate, in a liquid reaction medium devoid of inorganic acid anions other than of phosphoric acid, and then spray- or freeze-drying the suspension thus obtained.

Abstract: Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.

Abstract: The object of the present invention is to prepare a calcium hydrogen phosphate that has excellent binding properties, a large oil adsorption capacity and a specific surface area, and is therefore suitable as an excipient.A scale-like calcium hydrogen phosphate is prepared by reacting phosphoric acid with an alkaline calcium compound such as quick lime, in the presence of a multivalent organic acid with coordinating ability, such as citric acid, to obtain a columnar calcium hydrogen phosphate, and then hydrothermally treating the obtained columnar calcium hydrogen phosphate at a temperature of 60.degree. C. or higher.

Abstract: The instant invention describes a method for preparing a stable, anhydrous non-hygroscopic zinc phosphate compound which is suitable for use as a batch material in the preparation of zinc-phosphate glasses. This method comprises three basic steps: first, forming an aqueous slurry mixture by intimately mixing a mixture containing phosphoric acid and a zinc-containing compound whereby the so-formed slurry mixture is comprised of a mixture of zinc hydrogen phosphates and exhibits a P.sub.2 O.sub.5 /ZnO weight ratio range between about 1.2 to 2.0; second, heating the so-formed slurry mixture to a temperature and for a time sufficient to achieve both a removal of a sufficient amount of water and the phase transformation of the zinc hydrogen phosphates resulting in zinc-phosphate material comprised of granular solid mixture of zinc metaphosphates and zinc pyrophosphate and third, cooling the zinc-phosphate material to room temperature.

Abstract: This invention involves new compositions and methods of use and delivery of amorphous calcium compounds such as: amorphous calcium phosphate (ACP), amorphous calcium phosphate fluoride (ACPF), amorphous calcium carbonate phosphate (ACCP), amorphous calcium carbonate phosphate fluoride (ACCPF), and amorphous calcium fluoride (ACF) for use in remineralizing and fluoridating teeth. These amorphous compounds or solutions which form the amorphous compounds, when applied either onto or into dental tissue prevent and/or repair dental weaknesses such as dental caries, exposed roots and dentin sensitivity. The compounds have the highest solubilities, fastest formation rates and fastest conversion rates (to apatite) among all the calcium phosphates under physiological conditions. Moreover, in the presence to fluoride the amorphous compound convert rapidly to fluoride containing apatite.