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Linear dimensional change during setting of a zinc phosphate cement
Author(s) -
ØILO GUDBRAND
Publication year - 1975
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/j.1365-2842.1975.tb01529.x
Subject(s) - cement , materials science , mercury (programming language) , zinc , zinc phosphate , dental cement , nuclear chemistry , metallurgy , composite material , chemistry , adhesive , layer (electronics) , computer science , programming language
Summary A method for studying the linear dimensional changes of dental cements during setting has been described. The measurements started 3 min after commencing the mix with specimens placed on a mercury bath. Measurements were performed at 37°C a.nd under various environmental humidity. The specimens were made of a fine grain zinc phosphate cement with high powder/ liquid ratio (3/1: g/ml) and low powder/liquid ratio (2/1: g/ml), and the measurements showed that the cement contracted during setting under both wet and dry conditions. Under wet conditions cements with both high and low powder/liquid ratio showed the same contraction, with 0.43% after 30 min reaching a maximum of 0‐66% after 1 day. Under dry conditions the contraction was more pronounced, and somewhat dependent on the powder/liquid ratio. The cement with the high powder/liquid ratio showed 1.33% contraction after 30 min with a maximum of 3.83% after 7 days, whereas the corresponding values for cement with low powder/liquid ratio were 0.79% and 4.76%.