Dynamic mechanical properties of amalgams

✍ Scribed by Kusy, R. P. ;Greenberg, A. R.

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 687 KB
• Volume: 15
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820150109

✦ Synopsis

A recently developed dynamic mechanical analysis technique was utilized to determine the setting rates of dental amalgams. Via a compound parallel beam apparatus the dynamic mechanical properties of five amalgam materials were continuously measured at 37°C within ca. 7 min after the start of trituration. Over a 15 h r period results showed that the modulus of elasticity ( L , ? ) increased from 1.2 X l o i o Pa to 6.5 X 10'" Pa-the latter generally approaching those values reported via ultrasonic techniques. Moduli results via compression tests o n microspecimens (3 X 2 X 1 m m ) paralleled previous reliable literature data, nominally yielding values for E, of 2-3 X IO'O Pa. The extent of E , scatter from both inter-and intrapreparer experiments appeared similar, although superior technique generally could be recognized by a systematic shift of the mean results to higher E,'s. In addition to modulus studies both compressive strengths (urnax) a n d their corresponding strains ( 6 ) were measured u n microspecimens at a strain rate (i) of 0.031 min-', with a significant increase being noted in omax for t h e one material tested at over a n order of magnitude increase in i .