The physical-mechanical performance of the new Ketac Molar Easymix compared to commercially available glass ionomer restoratives.
OBJECTIVE
To evaluate the time dependence of physical-mechanical performance of glass ionomer restoratives.


METHODS
The physical-mechanical properties of Ketac Molar Easymix in comparison to four handmix glass ionomer restoratives were evaluated by testing the compressive and flexural strength, acid erosion and solubility. By testing the properties in the early and late setting phase it was determined how fast the level of material characteristics is achieved. IR spectroscopy was used for monitoring the acid-base reaction.


RESULTS
The compressive strength after 1 and 24h setting time show that Ketac Molar Easymix and Fuji IX demonstrate a significantly higher performance. Ketac Molar Easymix exhibits by far the highest flexural strength 1h after start of setting. After 24h, it remains at this high level and only Vitro Molar and Fuji IX come close. Ketac Molar Easymix and Fuji IX show the lowest solubility in neutral media after 24h and 7d. It is remarkable that the solubilities of Ionofil Molar, Vitro Molar and Vidrion R stored in water for 24h are higher than those of Ketac Molar Easymix and Fuji IX obtained after 7d water immersion. In acidic media Ketac Molar Easymix is least prone to acid erosion.


CONCLUSIONS
For clinical success of a filling material the early achievement of a high physical-mechanical performance is mandatory to minimize the risk of early damage to a restoration. With the high flexural strength reached after 1h combined with the lowest susceptibility for acid-attack and solubility in water, Ketac Molar Easymix, from 3M ESPE, provides the best performance of any materials tested.
3M ESPE AG, ESPE Platz, 82229 Seefeld, Germany. robert.peez@mmm.com
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Peez
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Frank
D000704:Analysis of Variance; D019245:Compressive Strength; D003343:Corrosion; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements / Q000737:chemistry; D007101:Immersion; D019344:Lactic Acid; D018583:Pliability; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
D005899:Glass Ionomer Cements; C515713:Ketac Molar Easymix; D019344:Lactic Acid