| 1388 The Effects of Ultrasonically Setting Glass Ionomer Cements | ||||||||||||||||||||||||||||||||||||||||||||||
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M.R. TOWLER, Materials and Surface Science Institute, University of Limerick, Limerick, Ireland, E. TWOMEY, Department of Mechanical and Aeronautical Engineering, University of Limerick, Limerick, Ireland, C.M. CROWLEY, Materials Ireland Research Centre, National Technological Park, Limerick, Ireland, J. DOYLE, Materials Ireland Research Centre, Limerick, Ireland, and S. HAMPSHIRE, Materials Ireland Research Centre, National Technological Park, Limerick Objective: Determination of the influence of ultrasonic irradiation on the setting times and compressive strengths of Ketac Molar Quick1 (KMQ) and Fuji IX Fast2 (FIXF) glass ionomer cements (GICs). Methods: The encapsulated GICs were activated and mixed following the manufacturers' directions and the setting times and compressive strengths were examined in accordance with ISO9917. However, sample sizes were reduced (3mmŲ x 5mm height) to mimic the clinical situation. Ultrasound, imparted from a Piezon Master 400 dental scaler3, was applied to the base of each sample. Results: Ultrasonic irradiation reduced the setting time of the cements with command setting being achieved following 45 seconds exposure (Table 1). Table 1: The influence of ultrasound upon the setting time of GICs
Ultrasonic irradiation also resulted in an improvement in the compressive strength (Table 2), with a relative increase of 12% and 18% at 1 day and 15% and 12% at 7 days, being observed for KMQ and FIXF, respectively. Table 2: The influence of ultrasound upon the compressive strength of GICs
Conclusions: Ultrasonic irradiation reduces the setting time of KMQ and FIXF, with command setting being achieved following 45 seconds irradiation. Ultrasound also increases the compressive strength of GICs, although the relative improvement is cement and maturation time dependant. The study was supported by the 5th Framework of the European Union (G5RD CT2001 00475). 1ESPE, Germany (Batch #00150014); 2GC, Japan (Batch #0107165); 3EMS, Switzerland. * Standard deviation | ||||||||||||||||||||||||||||||||||||||||||||||
| Seq #147 - Prosthodontic Polymers and Cements 12:30 PM-2:30 PM, Thursday, 11 March 2004 Hawaii Convention Center 325-B | ||||||||||||||||||||||||||||||||||||||||||||||
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Back to the Dental Materials: VI - Polymer Materials-Mechanical Properties and Degradation Program
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