The use of acoustic microscopy to study the mechanical properties of glass-ionomer cement L.A. Denisova a, *, R.G. Maev b , I.Ya. Poyurovskaya c , T.V. Grineva d , A.F. Denisov a , E.Yu. Maeva b , E.Yu. Bakulin a a The Emanuel’s Institute for BioChemical Physics of the Russian Academy of Science, 4, Kosygin Street, 119991 Moscow, Russia b The School of Physical Science of the Windsor University, 401 Sunset Avenue, Windsor Ontario, Canada N9B3P4 c The Central Research Dental Institute, 16, Frunze Street, Moscow 119840, Russia d “Stomadent Ltd”, 11, Garshin Street, Tomolino, Moscow Region, 140070, Russia Received 1 May 2002; received in revised form 28 April 2003; accepted 10 June 2003 KEYWORDS Non-destructive evaluation; Dental cement; Mechanical properties; Microstructure; Acoustic properties; Acoustic microscopy Summary Objectives. The aim of the study was to investigate the relationship between microstructure, acoustic and mechanical properties of hardened dental cement samples, prepared with different powder/water ratios. Methods. Glass-ionomer dental cement samples, prepared with a standard amount of cement powder and different amounts of water have been examined after being hardened. Surface microstructure and ultrasound, longitudinal and shear velocities were obtained with a scanning acoustic microscope. Conditional effective elastic modulus and Poisson’s ratio have been calculated using longitudinal and shear sound velocity values. Then on the same samples elastic modulus and microhardness have been determined by standard tests. Additional samples have been used to determine compressive strength. Results. Density; conditionally instantaneous elastic modulus; high-elasticity modulus and compression strength of the samples decrease when large amounts of water were used for their preparation. At the same time porosity and microhardness of the cement matrix increase. Acoustic parameters and parameters of elasticity, calculated on the basis of sound velocity, demonstrated changes, similar to those obtained in standard mechanical tests. Significance. The established relation between microstructure, acoustic and mechanical parameters demonstrated a high capacity of acoustic microscopy application for non-destructive characterization of dental materials. A particular advantage of the acoustic microscopy is the opportunity to evaluate microstructure and mechanical properties on the same sample. Q 2003 Published by Elsevier Ltd on behalf of Academy of Dental Materials. All rights reserved. Introduction Ultrasound methods are widely used in the evaluation of properties in construction cement Dental Materials (2004) 20, 358–363 http://intl.elsevierhealth.com/journals/dema 0109-5641/$ - see front matter Q 2003 Published by Elsevier Ltd on behalf of Academy of Dental Materials. All rights reserved. doi:10.1016/S0109-5641(03)00129-5 *Corresponding author. Tel.: þ7-95-137-83-47; fax: þ 7-95- 137-41-01. E-mail address: isi@com2com.ru