Results 171 to 180 of about 24,238 (226)

Structure of Zinc Phosphate Dental Cement

Journal of Dental Research, 1971
The zinc phosphate cement structure consists of excess zinc oxide particles in a non-crystalline, amorphous phosphate matrix. Crystals of hopeite (Zn3(PO4) 2·4H2O) can grow from the cement surface if excess water is present. Extensive pores and surface layers of crystals, which are dependent on moisture conditions, affect the strength and adhesive ...
G E, Servais, L, Cartz
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Surface Structure of Zinc Phosphate Dental Cements

Journal of Dental Research, 1972
When zinc phosphate cement is formed enclosed between a glass plate and a tooth surface, it retains the excess moisture available at the time of setting. This causes the cement surfaces to become covered with weakly held crystals of hopeite (3 ZnO·P2 O5 · 4 H2O).
L, Cartz, G, Servais, F, Rossi
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Influence of phytic acid on zinc phosphate cement

Acta Odontologica Scandinavica, 1994
The influence of phytic acid on the properties of zinc phosphate cement was studied by adding 2-13 wt% phytic acid to the liquid. Improved mechanical strength and stability were found for some cements prepared from commercial powders when liquids with increased phytic acid content were used.
J, Li, S, Forberg, R, Söremark
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Enamel Corrosion Produced by Zinc Phosphate Dental Cement

Journal of Dental Research, 1976
The surface of tooth enamel that had been left in contact with a phosphoric acid solution or a zinc phosphate cement mix was studied by scanning electron microscopy. Both treatments modified enamel surface topography. The modifications were represented by cavities of varying extension and depth.
A, Abramovich, R L, Macchi, L M, Ribas
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Retention of cast posts cemented with zinc phosphate cement using different cementing techniques

Journal of Prosthodontics, 2001
Purpose This study compares the effect of different cementation techniques on the retention of cast posts and cores.Materials and Methods Twenty‐four extracted single rooted human teeth were used in this study. After routine preparation of the root canals, the canal space was enlarged with reamers.
Z, Fakiha, A, Al-Aujan, S, Al-Shamrani
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Laboratory strength of glass ionomer and zinc phosphate cements

Journal of Prosthodontics, 2001
Purpose The present in vitro study examined 3 mechanical properties, namely compressive, flexural, and diametral tensile strength, of various commercially available cements and core materials as a function of time after mixing.Materials and Methods The examined materials were 2 cermet cements (Ketac Silver [ESPE, Seefeld, Germany] and Chelon Silver ...
A, Piwowarczyk, P, Ottl, H C, Lauer
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Aspects of the chemistry of zinc phosphate cements

Australian Dental Journal, 1984
Abstract— Consideration of the ZnO‐P2O5‐H2O constitutional diagram gives some insights into the setting reaction of dental zinc phosphate cements, and clarifies the requirements of acid concentrations and clinical mixing procedure.
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Physical Properties of Some Zinc Phosphate and Polycarboxylate Cements

Acta Odontologica Scandinavica, 1983
Several physical properties were measured for two zinc phosphate and three polycarboxylate cements. The specimens were tested in compression 24 h after they had been made. Two series of specimens were examined. In one series the cement powders were given a correct treatment, protected from atmospheric humidity.
R, Branco, T, Hegdahl
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Zinc Phosphate Cements: Chemical Study of In Vitro Durability

Journal of Dental Research, 1970
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.
A D, Wilson, B E, Kent, B G, Lewis
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[Fatigue of dental zinc phosphate cement].

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices, 1992
The fatigue characteristics of a zinc phosphate cement were examined. Using a split mould made of stainless steel, 12 mm x phi 6 mm column shape specimens were prepared. Fatigue tests were done by loading partially repeated pulsating diametrical tensile stress of 1-20 Hz, minimum stress was 0.2 MPa (2.0 kgf/cm2) and maximum stress was 3.5-5.4 MPa (36 ...
K, Okazaki, F, Nishimura
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