Brian E. Kent

Glass Ionomer Cement Formulations: I. The Preparation of Novel Fluoroaluminosilicate Glasses High in Fluorine

The preparation of a large number of novel fluorine-containing aluminosilicate glasses is reported along with the properties of cements formed by their reaction to aqueous solutions of poly- (acrylic acid) (PAA).

Glass-ionomer Cement Formulations. II. The Synthesis of Novel Polycarboxylic Acids

The synthesis of many polycarboxylic acids is reported. An account is given of their stability in aqueous solution and the properties of cements formed by their reaction with ion-leachable glasses. A copolymer of acrylic and itaconic acids was found to combine several favorable characteristics.

Dental Silicate Cements: V. Electrical Conductivity

The variation of the electrical conductivity of dental silicate cements with age is described, and the effects of varying temperature, powder-liquid ratio, and constitution of the liquid are discussed. A correlation with specification solubility is shown for a number of commercial brands.

Zinc Phosphate Cements: Chemical Study of In Vitro Durability

This study of the variation in chemical composition of material eroded from zinc phosphate cements in aqueous mediums establishes the effects of preparative variables and pH.

Dental Silicate Cements: IV. Phosphoric Acid Modifiers

The effects of aluminum, zinc, and boric acid modifiers of the phosphoric acid liquid on the properties of the final cement are discussed, and conclusions are drawn as to the optimum conditions required for a good cement. Several commercial brands are examined in the light of the constitution of the liquids.

Dental Silicate Cements: IX. Decomposition of the Powder:

The initial phase of the reaction between powder and liquid has been investigated. Electrophilic attack by protons in the liquid results in the decomposition of the powdered glass with liberation of cations and fluoride ions. The extent of the attack depends on the degree of acidity of the liquid.

Dental Silicate Cements: VIII. Acid-Base Aspect

The decrease in acidity of dental silicate cements with age was studied and was considered to be a major factor controlling the setting reaction. Liquid type, powder/liquid ratio, temperature, and storage conditions profoundly affected cement acidity.

Dental Silicate Cements: X. The Precipitation Reaction

The precipitation of ions during the setting and hardening of cements has been studied by extraction of soluble materials at different stages during the aging process, followed by chemical analysis. Cement formation arises from precipitation of aluminum, zinc, and calcium phosphates in conjunction with a siliceous gel phase.

Dental Silicate Cements: XV. Effect of Particle Size of the Powder

The effects of particle size of the powder on the physical and chemical properties of dental silicate cements were studied. Suggestions are given for improvement of these cements by changes in the particle size distribution of the powder.

Dental Silicate Cements: XI. Electron Probe Studies

Electron probe studies on polished sections of dental silicate cement show that it consists of well-defined particles embedded in a phosphate matrix. The matrix contains phosphorus, aluminum, and calcium but no silicon. The calcium and aluminum originate from the particle surface, which becomes an aluminosilica gel, whereas the phosphorus is derived from the cement liquid.