Influence of storage humidity on hardness of light-cured glass polyalkenoate cements.
The influence of storage in various environments on the hardness of four commercial light-cured glass polyalkenoate cements and one conventional glass polyalkenoate cement was investigated. Specimens with or without light exposure were stored for 7 days in different humidity conditions. A hardness tester with a diamond indenter point was used and Vickers hardness numbers under minor load conditions were determined. Non-light-exposed specimens did not increase in hardness in either dry or wet conditions. Light-exposed specimens became harder with time in dry conditions. Light-exposed specimens stored in wet conditions hardened only slightly. To investigate the effects of humidity, some light-exposed specimens stored first in wet conditions were stored another 7 days in dry conditions. They became as hard as those first stored in dry conditions for 7 days. It is concluded that the hardness of these cements corresponds with the humidity of the storage environment.
Tsuruta
S
S
Department of Dental Material Science, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
Viohl
J
J
D000180:Acrylic Resins / Q000737:chemistry; D004356:Drug Storage; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006244:Hardness; D006813:Humidity; D008027:Light; D008298:Maleates / Q000737:chemistry; D008422:Materials Testing; D012117:Resins, Synthetic / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000180:Acrylic Resins; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D008298:Maleates; D012117:Resins, Synthetic; C081982:VariGlass VLC; D014867:Water; C067790:Vitrabond; C084541:Fuji glass-ionomer lining cement; C040964:Ketac-Fil