Publicação
Influence of exposure time and light intensity on depth of cure of Bulk-fill resin composite
| Resumo: | Objectives: To evaluate influence of the light curing method on the microhardness and the depth of cure of six bulk-fill composite resins. To compare two methods used to determine the depth of cure of composite resins. Materials and Methods: Depth of cure was determined according to ISO-4049 and microhardness ratio. Specimens were divided by 24 experimental groups according to the possible combinations between composite [Tetric EvoCeram Bulk Fill (Ivoclar- Vivadent), x-tra base (Voco), x-tra fil (Voco), Filtek Bulk Fill (3M-ESPE), SonicFill (Kerr) and SDR (Dentsply) and curing method (600mW/cm2–20s; 1200mW/cm2–10s; 600mW/cm2–40s; 1200mW/cm2–20s)]. Using a teflon mould, specimens (2x2x7 mm) were made to analyse Knoop microhardness on the top of the specimens and depth of cure according to microhardness ratio (n=5). Two specimens per group were made to determine depth of cure by ISO-4049 instructions (n=2). Microhardness data were analysed with Kruskal-Wallis followed by LSD post-hoc tests (p<0.05). Results: Microhardness values ranged from 14.2 KHN (Filtek Bulk Fill, 1200mW/cm2– 10s) to 51.5 KHN (SonicFill, 1200mW/cm2–20s). Base composite resins (x-tra base, Filtek Bulk Fill e SDR) showed a statistically (p<0.05) lower microhardness then fill composites (x-tra fil, Tetric EvoCeram Bulk Fill and SonicFill). No significantly differences were found between the curing methods (p=0.244). ISO depth of cure ranged between 2.92 mm (Tetric Evoceram Bulk Fill – 600mW/cm2–20s) and 4.97 mm (x-tra base – 600mW/cm2–40s). Ratio depth of cure ranged from 4 mm [x-tra fill 1200mW/cm2-20s, Filtek Bulk Fill (600mW/cm2-20s; 600mW/cm2-40s; 1200mW/cm2- 20s)] to 1 mm [Tetric Evoceram Bulk Fill (600mW/cm2-20s; 1200mW/cm2-10s)]. Conclusion: Fill composite resins microhardness was higher than base composites. The top microhardness was not affected by the curing method. Not all composites yielded the depth of cure claimed by manufactures. ISO 4049 recommended method afforded higher depth of cure than the one obtained by microhardness ratio tests. |
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| Autores principais: | Catalão, Frederico de Almeida Portugal |
| Assunto: | Materiais dentários Teses de mestrado - 2013 |
| Ano: | 2013 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Objectives: To evaluate influence of the light curing method on the microhardness and the depth of cure of six bulk-fill composite resins. To compare two methods used to determine the depth of cure of composite resins. Materials and Methods: Depth of cure was determined according to ISO-4049 and microhardness ratio. Specimens were divided by 24 experimental groups according to the possible combinations between composite [Tetric EvoCeram Bulk Fill (Ivoclar- Vivadent), x-tra base (Voco), x-tra fil (Voco), Filtek Bulk Fill (3M-ESPE), SonicFill (Kerr) and SDR (Dentsply) and curing method (600mW/cm2–20s; 1200mW/cm2–10s; 600mW/cm2–40s; 1200mW/cm2–20s)]. Using a teflon mould, specimens (2x2x7 mm) were made to analyse Knoop microhardness on the top of the specimens and depth of cure according to microhardness ratio (n=5). Two specimens per group were made to determine depth of cure by ISO-4049 instructions (n=2). Microhardness data were analysed with Kruskal-Wallis followed by LSD post-hoc tests (p<0.05). Results: Microhardness values ranged from 14.2 KHN (Filtek Bulk Fill, 1200mW/cm2– 10s) to 51.5 KHN (SonicFill, 1200mW/cm2–20s). Base composite resins (x-tra base, Filtek Bulk Fill e SDR) showed a statistically (p<0.05) lower microhardness then fill composites (x-tra fil, Tetric EvoCeram Bulk Fill and SonicFill). No significantly differences were found between the curing methods (p=0.244). ISO depth of cure ranged between 2.92 mm (Tetric Evoceram Bulk Fill – 600mW/cm2–20s) and 4.97 mm (x-tra base – 600mW/cm2–40s). Ratio depth of cure ranged from 4 mm [x-tra fill 1200mW/cm2-20s, Filtek Bulk Fill (600mW/cm2-20s; 600mW/cm2-40s; 1200mW/cm2- 20s)] to 1 mm [Tetric Evoceram Bulk Fill (600mW/cm2-20s; 1200mW/cm2-10s)]. Conclusion: Fill composite resins microhardness was higher than base composites. The top microhardness was not affected by the curing method. Not all composites yielded the depth of cure claimed by manufactures. ISO 4049 recommended method afforded higher depth of cure than the one obtained by microhardness ratio tests. |
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