Effect of radiant heat and ultrasound on fluoride release and surface hardness of glass ionomer cements.
OBJECTIVE
The purpose of this investigation was to evaluate the influence of radiant heat and ultrasound on fluoride release and surface hardness of 3 glass ionomer cements (GICs).


METHODS
There were 3 experimental groups for each GIC; in group 1, the specimens were left to set without any treatment; in group 2, the specimens were irradiated for 2 minutes using a LED unit; and in group 3, ultrasound was applied using a scaler for 55 seconds on the specimen surface. Fluoride release measurements were performed daily for 7 days and at days 14 and 28. Surface hardness of the tested GICs was determined using Vickers method. The measurements were performed 24 hours and 7 days after mixing. Statistical analysis of the data was made using 1-way ANOVA and Tukey's and Bonferroni post hoc tests (α = 0.05).


RESULTS
Radiant heat during setting reduced the fluoride release and increased the surface hardness of GICs (p&lt;0.05). Ultrasonic treatment also reduced the fluoride release and increased the surface hardness (p&lt;0.05) of GICs but in lower extent. Among the GICs there were differences in fluoride release and surface hardness properties depending on their composition (p&lt;0.05).


CONCLUSIONS
Radiant heat and ultrasonic treatments may be useful methods for GIC restorations in order to achieve faster adequate initial mechanical properties.
Department of Operative Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki - Greece.
Kosmas
K
Tolidis
Department of Operative Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki - Greece.
Dimitrios
D
Dionysopoulos
Department of Operative Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki - Greece.
Paris
P
Gerasimou
Department of Operative Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki - Greece.
Thrasyvoulos
T
Sfeikos
D005459:Fluorides / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006358:Hot Temperature; D013499:Surface Properties; D000069453:Ultrasonic Waves
D005899:Glass Ionomer Cements; D005459:Fluorides