Effect of light-curing methods and indirect veneering materials in a resin cement Knoop hardness

Este estudo avaliou a dureza Knoop do cimento resinoso dual (Rely-x) ativado quimicamente (grupo controle) ou química/fisicamente (dual). Antes da ativação, uma faceta de 1,5mm de espessura da cerâmica {HeraCeram) ou compósito (Artglass) foi colocada sobre o cimento. No grupo dual, a fotoativação foi realizada com aparelho de luz de lâmpada halógena convencional (XL2500), por 40s (QHT); luz emitida por diodos (Ultrablue Is), por 40s (LED); e arco de plasma de Xenónio (Apollo 95E), por 3s (PAC). Um incisivo bovino teve sua face vestibular planificada e hibridizada. Sobre esta superfície, uma matriz de borracha (5mm de diâmetro e 1mm de altura) foi preenchida com cimento. Assentou-se uma tira de poliéster para fotoativação direta ou através de um disco dos materiais para faceta. Após armazenamento em ambiente seco e escuro (24h/37°C), as amostras (n=5) foram seccionadas para mensuração dos valores de dureza (KHN), obtidos em um aparelho microdurômetro (50gf/15s). Os dados foram submetidos à análise de variância e ao teste de Tukey (<x=,05). O cimento apresentou maiores valores de dureza Knoop com Artglass para QHT e LED, comparado ao HeraCeram. O grupo controle e grupo PAC/Artglass mostraram os valores de dureza mais baixos comparados aos grupos fotoativados com QHT e LED. A combinação PAC/HeraCeram resultou nos piores valores de dureza do cimento.This study evaluated the Knoop hardness of the dual-cured resin cement (Rely-X) activated by solely Chemical reaction (control group) or by chemical/ physical mode, light-cured through 1.5mm thick ceramic (HeraCeram) or composite (Artglass). Light curing was carried out using conventional halogen light (XL2500), for 40s (QHT); light emitted by diodes (Ultrablue Is), for 40s (LED); and Xenon plasma are (Apollo 95E), for 3s (PAC). A bovine incisor had its buccal face flattened and hybridized. On this surface a rubber mold (5mm in diameter and 1mm in height) was bulk filled with cement. A polyester strip was seated for direct light curing or through a disc of veneering material. After storage dry in dark (24h/37°C), samples (n=5) were sectioned for hardness (KHN) measurements, taken in a microhardness tester (50gf load/15s). Data were submitted to ANOVA and Tukey\u27s test (a=.05). The cement presented higher Knoop hardness values with Artglass for QHT and LED, compared to HeraCeram. The control group and PAC/Artglass group showed lower hardness values compared to groups light-cured with QHT and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values

Effect Of Light-curing Methods On Resin Cement Knoop Hardness At Different Depths.

This study evaluated, using Knoop hardness test, the polymerization depth of Rely-X dual-cured resin cement activated by chemical reaction alone (control group) or by chemical/physical mode with light curing through a 1.5-mm-thick ceramic layer (HeraCeram). Bovine incisors had their buccal surface flattened and hybridized. On this surface, a rubber mould (5 mm diameter; 1 mm high) was bulk filled with cement. Either a polyester strip or a 1.5-mm-thick disc of the veneering material was seated over this set. Light curing was performed with either conventional halogen light (QTH; XL2500) for 40 s, light-emitting diode (LED; Ultrablue Is) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. In a control group, cement setting occurred by chemical reaction alone. After storage dry in dark (24 h/37 degrees C), the specimens (n=5) were sectioned for hardness (KHN) measurements at three depths in a microhardness tester (50 gf load/15 s). Data were submitted to ANOVA and Tukey's test (alpha = 0.05). Rely-X cement presented higher Knoop hardness values when the QTH and LED LCUs were used, compared to the control group and PAC. Light curing with PAC resulted in lower hardness compared to the control group. Cement hardness was significantly lower in deeper regions.18305-

Effect of light-curing method and indirect veneering materials on the Knoop hardness of a resin cement

This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC) activated solely by chemical reaction (control group) or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram) or composite (Artglass) disc. Light curing was carried out using conventional halogen light (XL2500) for 40 s (QTH); light emitting diodes (Ultrablue Is) for 40 s (LED); and Xenon plasma arc (Apollo 95E) for 3 s (PAC). Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height) was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37°C), the samples (n = 5) were sectioned for hardness (KHN) measurements, taken in a microhardness tester (50 gF load 15 s). The data were statistically analyzed by ANOVA and Tukey's test (&#945; = 0.05). The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values

Effect Of Light-curing Method And Indirect Veneering Materials On The Knoop Hardness Of A Resin Cement.

This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC) activated solely by chemical reaction (control group) or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram) or composite (Artglass) disc. Light curing was carried out using conventional halogen light (XL2500) for 40 s (QTH); light emitting diodes (Ultrablue Is) for 40 s (LED); and Xenon plasma arc (Apollo 95E) for 3 s (PAC). Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height) was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37 degrees C), the samples (n = 5) were sectioned for hardness (KHN) measurements, taken in a microhardness tester (50 gF load 15 s). The data were statistically analyzed by ANOVA and Tukey's test (alpha = 0.05). The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values.23108-1