The effect of light curing units, curing time, and veneering materials on resin cement microhardness
Background/purpose: Several factors may affects microhardness of resin cement under veneering materials. The aim of this study was to evaluate the effect of different veneering materials, light-curing units and curing times (20/3, 40/6) on the microhardness of dual-cured resin cement. Materials and...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2013-06-01
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| Series: | Journal of Dental Sciences |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1991790212001560 |
| _version_ | 1818930105811992576 |
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| author | Nurcan Ozakar Ilday Yusuf Ziya Bayindir Funda Bayindir Aysel Gurpinar |
| author_facet | Nurcan Ozakar Ilday Yusuf Ziya Bayindir Funda Bayindir Aysel Gurpinar |
| author_sort | Nurcan Ozakar Ilday |
| collection | DOAJ |
| description | Background/purpose: Several factors may affects microhardness of resin cement under veneering materials. The aim of this study was to evaluate the effect of different veneering materials, light-curing units and curing times (20/3, 40/6) on the microhardness of dual-cured resin cement.
Materials and methods: We pressed dual-cured resin cement specimens (Clearfil SA cement, 5 mm diameter, 1 mm thick) between two microscopic glass slides covered with transparent polystyrene matrix strips to remove excess material, then irradiated them through a ceramic disc and a composite disc (A2 Esthet X HD, Dentsply, Caulk) with three types of high-power light-curing units as follows: conventional halogen light (quartz tungsten halogen) for 20/40 s, light-emitting diodes for 20/40 s and xenon plasma arc for 3/6 s. The control group specimens were cured under two layer transparent polyester matrix strips (n = 5). After dry storage in the dark (24 h/37°C), we recorded specimens’ Vickers microhardness numbers (50 gF load/15 s) and made three indentations on the bottom surface of each one. Data were analyzed using analysis of variance and post-hoc comparisons using Duncan’s test and the Student t test with a significance level of 5%.
Results: Analysis of variance revealed significant differences in microhardness resulting from the different curing units, veneering materials and polymerization times (P < 0.05). The light-emitting diode curing unit produced higher microhardness values compared to the conventional halogen light and plasma arc light sources (P < 0.05). Both veneering materials, ceramic, and composite resin, exhibited significantly lower microhardness values than those of the control group (P < 0.05). Extended polymerization time increased mean surface microhardness values of the resin cement specimens (P < 0.05).
Conclusion: Light-curing units, curing time, and veneering materials are important factors for achieving adequate dual cure resin composite microhardness. High-intensity light and longer curing times resulted in the highest microhardness values. |
| first_indexed | 2024-12-20T03:55:25Z |
| format | Article |
| id | doaj.art-d3e6c5b844584ed5b9113f0a59d33731 |
| institution | Directory Open Access Journal |
| issn | 1991-7902 |
| language | English |
| last_indexed | 2024-12-20T03:55:25Z |
| publishDate | 2013-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Dental Sciences |
| spelling | doaj.art-d3e6c5b844584ed5b9113f0a59d337312022-12-21T19:54:21ZengElsevierJournal of Dental Sciences1991-79022013-06-018214114610.1016/j.jds.2012.09.014The effect of light curing units, curing time, and veneering materials on resin cement microhardnessNurcan Ozakar Ilday0Yusuf Ziya Bayindir1Funda Bayindir2Aysel Gurpinar3Department of Restorative Dentistry, Atatürk University, Erzurum, TurkeyDepartment of Restorative Dentistry, Atatürk University, Erzurum, TurkeyDepartment of Prosthodontics, Atatürk University, Erzurum, TurkeyDepartment of Restorative Dentistry, Atatürk University, Erzurum, TurkeyBackground/purpose: Several factors may affects microhardness of resin cement under veneering materials. The aim of this study was to evaluate the effect of different veneering materials, light-curing units and curing times (20/3, 40/6) on the microhardness of dual-cured resin cement. Materials and methods: We pressed dual-cured resin cement specimens (Clearfil SA cement, 5 mm diameter, 1 mm thick) between two microscopic glass slides covered with transparent polystyrene matrix strips to remove excess material, then irradiated them through a ceramic disc and a composite disc (A2 Esthet X HD, Dentsply, Caulk) with three types of high-power light-curing units as follows: conventional halogen light (quartz tungsten halogen) for 20/40 s, light-emitting diodes for 20/40 s and xenon plasma arc for 3/6 s. The control group specimens were cured under two layer transparent polyester matrix strips (n = 5). After dry storage in the dark (24 h/37°C), we recorded specimens’ Vickers microhardness numbers (50 gF load/15 s) and made three indentations on the bottom surface of each one. Data were analyzed using analysis of variance and post-hoc comparisons using Duncan’s test and the Student t test with a significance level of 5%. Results: Analysis of variance revealed significant differences in microhardness resulting from the different curing units, veneering materials and polymerization times (P < 0.05). The light-emitting diode curing unit produced higher microhardness values compared to the conventional halogen light and plasma arc light sources (P < 0.05). Both veneering materials, ceramic, and composite resin, exhibited significantly lower microhardness values than those of the control group (P < 0.05). Extended polymerization time increased mean surface microhardness values of the resin cement specimens (P < 0.05). Conclusion: Light-curing units, curing time, and veneering materials are important factors for achieving adequate dual cure resin composite microhardness. High-intensity light and longer curing times resulted in the highest microhardness values.http://www.sciencedirect.com/science/article/pii/S1991790212001560curing lightsmicrohardnessresin cementsveneering materials |
| spellingShingle | Nurcan Ozakar Ilday Yusuf Ziya Bayindir Funda Bayindir Aysel Gurpinar The effect of light curing units, curing time, and veneering materials on resin cement microhardness Journal of Dental Sciences curing lights microhardness resin cements veneering materials |
| title | The effect of light curing units, curing time, and veneering materials on resin cement microhardness |
| title_full | The effect of light curing units, curing time, and veneering materials on resin cement microhardness |
| title_fullStr | The effect of light curing units, curing time, and veneering materials on resin cement microhardness |
| title_full_unstemmed | The effect of light curing units, curing time, and veneering materials on resin cement microhardness |
| title_short | The effect of light curing units, curing time, and veneering materials on resin cement microhardness |
| title_sort | effect of light curing units curing time and veneering materials on resin cement microhardness |
| topic | curing lights microhardness resin cements veneering materials |
| url | http://www.sciencedirect.com/science/article/pii/S1991790212001560 |
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