Effect of the increase of energy density on knoop hardness of dental composites light-cured by conventional QTH, LED and xenon plasma arc
The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and...
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Veröffentlicht in: | Brazilian dental journal 2005-12, Vol.16 (3), p.218-224 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and polymerized using different light-curing units and times: conventional QTH (quartz-tungsten-halogen; 700 mW/cm²; 20 s, 30 s and 40 s); LED (light-emitting diode; 440 mW/cm²; 20 s, 30 s and 40 s); PAC (xenon plasma arc; 1700 mW/cm²; 3 s, 4.5 s and 6 s). The specimens were stored at 37°C for 24 h prior to sectioning for Knoop hardness assessment. Three measurements were obtained for each depth: top surface, 1 mm and 2 mm. Data were analyzed statistically by ANOVA and Tukey's test (p |
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ISSN: | 0103-6440 0103-6440 |
DOI: | 10.1590/S0103-64402005000300009 |