Biomaterial Database

The effects of additives on the thermal behaviour of gypsum-bonded casting investments. Part I. 1975

R Earnshaw

In the formulation of gypsum-bonded casting investments, small amounts of certain modifiers are sometimes added to increase the investment's thermal expansion. In the present investigation, a systematic study has been made of the effects on thermal expansion of adding boric acid and sodium chloride to the investment powder, and glycerol to the mixing water. The combination of 0.2 per cent of sodium chloride in the powder, and 10 per cent of glycerol in the mixing water, appears to offer most promise in the formulation of an investment with a high thermal expansion.

UI	MeSH Term	Description	Entries
D011791	Quartz	Quartz (SiO2). A glassy or crystalline form of silicon dioxide. Many colored varieties are semiprecious stones. (From Grant & Hackh's Chemical Dictionary, 5th ed)
D001888	Boric Acids	Inorganic and organic derivatives of boric acid either B(OH)3 or, preferably H3BO3.	Acids, Boric
D002133	Calcium Sulfate	A calcium salt that is used for a variety of purposes including: building materials, as a desiccant, in dentistry as an impression material, cast, or die, and in medicine for immobilizing casts and as a tablet excipient. It exists in various forms and states of hydration. Plaster of Paris is a mixture of powdered and heat-treated gypsum.	Dental Gypsum,Dental Stone, Artificial,Gypsum,Plaster of Paris,Alabaster,Anhydrous Sulfate of Lime,Artificial Dental Stone,Calcium Sulfate (1:1), Dihydrate,Calcium Sulfate (1:1), Hemihydrate,Calcium Sulfate (2:1),Calcium Sulfate Dihydrate,Calcium Sulfate, Anhydrous,Calcium Sulfate, Dihydrate,Calcium Sulfate, Hemihydrate,Calcium Sulphate,Drierite,Gypsite,Gypsum, Dental,Karstenite,Stone, Artificial Dental
D003734	Dental Casting Investment	Material from which the casting mold is made in the fabrication of gold or cobalt-chromium castings. (Boucher's Clinical Dental Terminology, 4th ed, p168)	Casting Investment, Dental,Casting Investments, Dental,Dental Casting Investments,Investment, Dental Casting,Investments, Dental Casting
D005990	Glycerol	A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, or sweetening agent.	1,2,3-Propanetriol,Glycerin,1,2,3-Trihydroxypropane,Glycerine
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D012822	Silicon Dioxide	Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.	Silica,Aerosil,Aerosil 380,Cristobalite,Quso G-32,Quso G32,Tridymite,380, Aerosil,Dioxide, Silicon,G32, Quso,Quso G 32
D012965	Sodium Chloride	A ubiquitous sodium salt that is commonly used to season food.	Sodium Chloride, (22)Na,Sodium Chloride, (24)NaCl