RESUMO
The aim of this study was to evaluate the amount of radiating energy transmitted through lithium disilicate discs of different thicknesses and opacities with different curing units (CU). Discshaped specimens 8 mm in diameter and 1.5 mm or 0.7 mm thick were designed with Zbrush® and Cura 3D® software, milled from HT and MO IPS e-maxCAD blocks (Ivoclar Vivadent) with Ceramill Mikro 4 (Amann Girrbach, Austria) and processed according to manufacturer instructions. Thickness was checked with a Mitutoyo (México) caliper. Four groups (n=4) were formed: G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm), and the effect of three CUs: Coltolux (Coltene- Whaledent), LED.C, (Woodpecker Medical Instrument Co.Ltd) and Deepcure L(3M-ESPE) was tested Measurements were taken with a halogen and LED radiometer (Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) after applying the guide of each CU directly on the reading window (d) and after interposing each of the specimens. The ratio of transmitted energy was determined in each case and data was analyzed with repeated measures ANOVA and Tukey test for multiple comparisons. LED.C: d:1600 mW/cm2, G1: 0.31(0.00), G2: 0.14(0.00) G3: 0.54(0.01), G4: 0.38(0.01); Deepcure L: d:1500 mW/cm2, G1: 0.34(0.01), G2: 0.20(0,00), G3: 0.56(0.01), G4: 0.41(0.02); Coltolux: d:1275 mW/cm2, G1: 0.44(0.01), G2: 0.24(0,00), G3: 0.65(0.01), G4: 0.47(0,00). Statistically significant differences were found among the curing units (P<0.001) and for the interaction CU-thickness (P<0.001) and CU-opacity (P=0.023). Within the conditions of this study, the ratio of light transmitted through lithium disilicate structures is related to their thickness and opacity, and to the curing unit employed.
Uno de los factores relacionados con éxito de las restauraciones y prótesis de cerámica de matriz vítrea es el logro de una fijación adhesiva para lo cual la correcta polimerización del medio de fijación es un requisito fundamental. El objetivo de este trabajo fue valorar la transmitancia de una cerámica a base de disilicato de litio de diferentes opacidades y espesores, con distintas unidades de curado. Probetas con forma de discos de 8mm de diámetro y dos diferentes espesores (1.5 mm y 0.7 mm) fueron diseñadas con Zbrush® y Cura 3D®, maquinadas a partir de bloques HT y MO de IPS e-maxCAD (Ivoclar Vivadent) con Ceramill Mikro 4 (Amann Girrbach, Austria) y procesadas según instrucciones del fabricante. Se obtuvieron cuatro grupos (n=4): G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm),los espesores se controlaron con un calibre (Mitutoyo, México). A continuación, se registró la irradiancia con cada una de las unidades de curado (UC) Coltolux (Coltene- Whaledent) LED.C, (Woodpecker Medical Instrument Co.Ltd) y Deepcure L(3M-ESPE), aplicadas sobre la ventana de un radiómetro (Halogen and led radiometer Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) en forma directa (d), y luego de interponer los diferentes especímenes y se calculó la proporción de energía transmitida en cada caso. Los datos se analizaron con ANOVA de medidas repetidas y prueba de Tukey para las comparaciones múltiples. LED.C: d:1600 mw/ cm2, HT/0,7mm: 0,54(0,01), HT/1,5mm:0,31(0); MO/0,7mm: 0,38(0,01), MO/1,5mm: 0,14(0,00); Deepcure L: d:1500 mW/ cm2, HT/0,7 mm: 0,56(0,01), HT/1,5 mm: 0,34(0,01), MO/0,7 mm: 0,41(0,02), MO/1,5 mm: 0,20(0,00); Coltolux: d:1275 mw/ cm2, HT/0,7 mm:0,65 (0,01), HT/1,5 mm:0,44(0,01), MO/0,7 mm: 0,47(0,00), MO/1,5mm: 0,24(0,00). Se encontraron diferencias estadísticamente significativas entre las diferentes unidades de curado (P<0,001), y en la interacción unidades de curado-espesor (P<0,001) y unidades de curado-opacidad (P=0,023). La proporción de energía luminosa transmitida por una estructura de cerámica de disilicato de litio depende del espesor y opacidad de la restauración y de la unidad de curado utilizada.
Assuntos
Porcelana Dentária , Cimentos de Resina , Cerâmica , Teste de MateriaisRESUMO
ABSTRACT The aim of this study was to evaluate the amount of radiating energy transmitted through lithium disilicate discs of different thicknesses and opacities with different curing units (CU). Discshaped specimens 8 mm in diameter and 1.5 mm or 0.7 mm thick were designed with Zbrush® and Cura 3D® software, milled from HT and MO IPS e-maxCAD blocks (Ivoclar Vivadent) with Ceramill Mikro 4 (Amann Girrbach, Austria) and processed according to manufacturer instructions. Thickness was checked with a Mitutoyo (México) caliper. Four groups (n=4) were formed: G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm), and the effect of three CUs: Coltolux (Coltene- Whaledent), LED.C, (Woodpecker Medical Instrument Co.Ltd) and Deepcure L(3M-ESPE) was tested Measurements were taken with a halogen and LED radiometer (Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) after applying the guide of each CU directly on the reading window (d) and after interposing each of the specimens. The ratio of transmitted energy was determined in each case and data was analyzed with repeated measures ANOVA and Tukey test for multiple comparisons. LED.C: d:1600 mW/cm2, G1: 0.31(0.00), G2: 0.14(0.00) G3: 0.54(0.01), G4: 0.38(0.01); Deepcure L: d:1500 mW/cm2, G1: 0.34(0.01), G2: 0.20(0,00), G3: 0.56(0.01), G4: 0.41(0.02); Coltolux: d:1275 mW/cm2, G1: 0.44(0.01), G2: 0.24(0,00), G3: 0.65(0.01), G4: 0.47(0,00). Statistically significant differences were found among the curing units (P<0.001) and for the interaction CU-thickness (P<0.001) and CU-opacity (P=0.023). Within the conditions of this study, the ratio of light transmitted through lithium disilicate structures is related to their thickness and opacity, and to the curing unit employed.
RESUMEN Uno de los factores relacionados con éxito de las restauraciones y prótesis de cerámica de matriz vítrea es el logro de una fijación adhesiva para lo cual la correcta polimerización del medio de fijación es un requisito fundamental. El objetivo de este trabajo fue valorar la transmitancia de una cerámica a base de disilicato de litio de diferentes opacidades y espesores, con distintas unidades de curado. Probetas con forma de discos de 8mm de diámetro y dos diferentes espesores (1.5 mm y 0.7 mm) fueron diseñadas con Zbrush® y Cura 3D®, maquinadas a partir de bloques HT y MO de IPS e-maxCAD (Ivoclar Vivadent) con Ceramill Mikro 4 (Amann Girrbach, Austria) y procesadas según instrucciones del fabricante. Se obtuvieron cuatro grupos (n=4): G1(HT/1.5 mm), G2(MO/1.5 mm), G3(HT/0.7 mm) y G4(MO/0.7 mm),los espesores se controlaron con un calibre (Mitutoyo, México). A continuación, se registró la irradiancia con cada una de las unidades de curado (UC) Coltolux (Coltene- Whaledent) LED.C, (Woodpecker Medical Instrument Co.Ltd) y Deepcure L(3M-ESPE), aplicadas sobre la ventana de un radiómetro (Halogen and led radiometer Woodpecker® LM-1-Guilin Woodpecker Medical Instrument Co.Ltd) en forma directa (d), y luego de interponer los diferentes especímenes y se calculó la proporción de energía transmitida en cada caso. Los datos se analizaron con ANOVA de medidas repetidas y prueba de Tukey para las comparaciones múltiples. LED.C: d:1600 mw/ cm2, HT/0,7mm: 0,54(0,01), HT/1,5mm:0,31(0); MO/0,7mm: 0,38(0,01), MO/1,5mm: 0,14(0,00); Deepcure L: d:1500 mW/ cm2, HT/0,7 mm: 0,56(0,01), HT/1,5 mm: 0,34(0,01), MO/0,7 mm: 0,41(0,02), MO/1,5 mm: 0,20(0,00); Coltolux: d:1275 mw/ cm2, HT/0,7 mm:0,65 (0,01), HT/1,5 mm:0,44(0,01), MO/0,7 mm: 0,47(0,00), MO/1,5mm: 0,24(0,00). Se encontraron diferencias estadísticamente significativas entre las diferentes unidades de curado (P<0,001), y en la interacción unidades de curado-espesor (P<0,001) y unidades de curado-opacidad (P=0,023). La proporción de energía luminosa transmitida por una estructura de cerámica de disilicato de litio depende del espesor y opacidad de la restauración y de la unidad de curado utilizada.
RESUMO
OBJECTIVE: This study evaluated the effect of beam homogeneity on the microtensile bond strength (µTBS) of two adhesive resins to dentin. METHODS: One polywave light-emitting-diode (LED) LCU (Bluephase Style, Ivoclar Vivadent AG) was used with two different light guides: a regular tip (RT, 1010 mW/cm2 emittance) and a homogenizer tip (HT, 946 mW/cm2 emittance). The emission spectra and beam profiles were measured from both light guides. Extracted third molars were prepared for µTBS evaluation using two adhesive systems: Excite F (EXF) and Adhese Universal (ADU). Bond strength was calculated for each specimen (n = 10) at locations that correlated with the output of the two LED chips emitting blue (455 nm) and the one chip that emitted violet light (409 nm) after 24-hs and after one-year water-storage. The µTBS was analyzed using a four-way analysis of variance (factors: adhesive system, light guide, LED wavelength, and storage time) and post-hoc Tukey test (α = 0.05). RESULTS: EXF always delivered a higher µTBS than ADU (p < 0.0001), with the µTBS of ADU being about 20% lower than EXF. The light guide (p = 0.0259) and storage time (p = 0.0009) significantly influenced the µTBS. The LED wavelengths had no influence on the µTBS (p > 0.05). SIGNIFICANCE: Homogeneity of the emitted light beam was associated with higher 24-h µTBS to dentin, regardless of the adhesive tested. Also, differences in the composition of adhesives can affect their compatibility with restorative composites and their ability to maintain bonding over one year.