| 0620 Resistance to Aging and Polishability of Different Types of Composites Measured in Glossiness | ||
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O. NIHLAWI, S. ANDREANA, D.M. GOSPODARSKI, T.J. HILL, and G.W. TYSOWSKY, Ivoclar Vivadent, Amherst, NY, USA Aim: to assess the glossiness of different composites following curing, after polishing and different stages of aging. Methods: Five disks (2 cm diameter, 2 mm thickness) of microhybrid composite (Tetric Ceram (TC), Ivoclar Vivadent), reinforced microhybrid (Tetric Ceram HB (TC HB), Ivoclar Vivadent), microfilled (Heliomolar (He), Ivoclar Vivadent), reinforced microfilled (Heliomolar HB (He HB), Ivoclar Vivadent) and flowable microfilled (Heliomolar Flow (He Flow), Ivoclar Vivadent). The disks were prepared by applying composite materials against new clean glass slides, within Teflon rings. Gloss values were measured with a NOVOCURVE Small Area Glossmeter (Rhopoint Instrumentation LTD) and reported in gloss units (GU). Ten readings were recorded from different areas on each disk. Glossiness was measured at the following points: A: after curing (natural gloss); B: after polishing with a series of polishing burs (Astropol, Ivoclar Vivadent) to mimic polishing after final retouching of the restoration; C: after 48 hours of aging in Coca Cola, orange juice and unsweetened hot coffee for 8 hours intervals; D: after polishing following aging. Results: Table 1. Glossiness of Composites at different stages. Values in Gloss Units for TC, TC HB, HE, HE HB, HE Flow. Natural Gloss: 93.9, 92.5, 93.4, 92.3, 94; After Polishing: 75.7, 83.2, 84.0, 78.7, 79.7; After Aging: 61.3, 74.8, 85.5, 81, 78.1; Polishing After Aging: 81.8, 83.4, 84.0, 81.2, 79.6. The initial gloss value was not reached after polishing for any of the composites. Further, all the composites lost glossiness after being exposed to accelerated aging. All composites reached values similar to the glossiness after polishing. Once re-polished, the glossy values were similar prior to aging Conclusions: Polishing enables the clinician to regain the glossiness of the composites studied equal to a freshly placed restoration. | ||
| Seq #84 - Polymer Materials: Surface Characteristics; Surface Roughness and Polishing 3:45 PM-5:00 PM, Thursday, 13 March 2003 Henry B. Gonzalez Convention Center Exhibit Hall C | ||
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