Influence of light-exposure methods and depths of cavity on the microhardness of dual-cured core build-up resin composites
J. appl. oral sci
;
22(1): 44-51, Jan-Feb/2014. tab, graf
Artículo
en Inglés
| LILACS, BBO
| ID: lil-699917
ABSTRACT
Objective:
The purpose of this study was to evaluate the Knoop hardness number (KHN) of dual-cured core build-up resin composites (DCBRCs) at 6 depths of cavity after 3 post-irradiation times by 4 light-exposure methods. Material andMethods:
Five specimens each of DCBRCs (Clearfil DC Core Plus [DCP] and Unifil Core EM [UCE]) were filled in acrylic resin blocks with a semi-cylindrical cavity and light-cured using an LED light unit (power density 1,000 mW/cm2)at the top surface by irradiation for 20 seconds (20 s), 40 seconds (40 s), bonding agent plus 20 seconds (B+20 s), or 40 seconds plus light irradiation of both sides of each acrylic resin block for 40 seconds each (120 s). KHN was measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours, 24 hours, and 7 days post-irradiation. Statistical analysis was performed using repeated measures ANOVA and Tukey's compromise post-hoc test with a significance level of p<0.05.Results:
For both DCBRCs, at 0.5 hours post-irradiation, the 20 s and 40 s methods showed the highest KHN at depth of 0.5 mm. The 40 s method showed significantly higher KHN than the 20 s method at all depths of cavity and post-irradiation times, except UCE at depth of 0.5 mm (p<0.05). The 120 s method did not result in significantly different KHN at all depths of cavity and post-irradiation times (p>0.05). In DCP, and not UCE, at 24 hours and 7 days post-irradiation, the B+20 s method showed significantly higher KHN at all depths of cavity, except the depth of 0.5 mm (p<0.05).Conclusion:
KHN depends on the light-exposure method, use of bonding agent, depth of cavity, post-irradiation time, and material brand. Based on the microhardness behavior, DCBRCs are preferably prepared by the effective exposure method, when used for a greater depth of cavity. .
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Resinas Compuestas
/
Cementos de Resina
/
Curación por Luz de Adhesivos Dentales
/
Pruebas de Dureza
Tipo de estudio:
Estudios de evaluación
Idioma:
Inglés
Revista:
J. appl. oral sci
Asunto de la revista:
Odontología
Año:
2014
Tipo del documento:
Artículo
País de afiliación:
Japón
Institución/País de afiliación:
Nagasaki University Hospital/JP
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