Y K Kim1, S K Kim, K H Kim, T Y Kwon. 1. Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea.
Abstract
AIM: To evaluate the degree of conversion of one dual-cured resin cement light-cured through three fibre posts within extracted human teeth. METHODOLOGY: Fifteen mandibular premolars were root filled and then divided into three groups. Variolink II was light-cured through the posts (LP, D.T. Light-Post; PP, FRC Postec Plus; SP, Snowpost) within the root canal. The degree of conversion was obtained at 1 mm intervals in 9 mm-deep longitudinally sectioned root canals using an optical microscope connected to an FTIR spectrophotometer (n = 10). The light transmission of each post tested was also examined using UV-Vis spectroscopy. Data were analysed using ANOVA and Tukey's test (alpha = 0.05). RESULTS: The LP and PP posts revealed a light transmission of 10.2% and 7.7%, respectively, whereas the SP post exhibited a significantly lower value of 0.5%. The degree of conversion mean value ranged from 32.78% to 69.73% depending on the depth and type of post. For all the groups, there were significant decreases in the degree of conversion values for the middle region when compared with those for the cervical region (P < 0.05). Except at a depth of 1 mm, the SP group consistently exhibited significantly lower degree of conversion values than the other groups (P < 0.05). The linear regression analysis revealed a strong correlation between the light transmission of the posts and the overall degree of conversion value for each group (R(2) = 0.9888). CONCLUSIONS: The decrease in the degree of conversion for Variolink II relative to the depth was dependent on the light transmission capacity of the posts tested.
AIM: To evaluate the degree of conversion of one dual-cured resin cement light-cured through three fibre posts within extracted human teeth. METHODOLOGY: Fifteen mandibular premolars were root filled and then divided into three groups. Variolink II was light-cured through the posts (LP, D.T. Light-Post; PP, FRC Postec Plus; SP, Snowpost) within the root canal. The degree of conversion was obtained at 1 mm intervals in 9 mm-deep longitudinally sectioned root canals using an optical microscope connected to an FTIR spectrophotometer (n = 10). The light transmission of each post tested was also examined using UV-Vis spectroscopy. Data were analysed using ANOVA and Tukey's test (alpha = 0.05). RESULTS: The LP and PP posts revealed a light transmission of 10.2% and 7.7%, respectively, whereas the SP post exhibited a significantly lower value of 0.5%. The degree of conversion mean value ranged from 32.78% to 69.73% depending on the depth and type of post. For all the groups, there were significant decreases in the degree of conversion values for the middle region when compared with those for the cervical region (P < 0.05). Except at a depth of 1 mm, the SP group consistently exhibited significantly lower degree of conversion values than the other groups (P < 0.05). The linear regression analysis revealed a strong correlation between the light transmission of the posts and the overall degree of conversion value for each group (R(2) = 0.9888). CONCLUSIONS: The decrease in the degree of conversion for Variolink II relative to the depth was dependent on the light transmission capacity of the posts tested.
Authors: Priscilla Cristoforides Pereira; Renata Marques de Melo; Carolina Chaves; Graziela A P Galhano; Marco Antonio Bottino; Ivan Balducci Journal: J Appl Oral Sci Date: 2010 Sep-Oct Impact factor: 2.698
Authors: João Fernando Bazzo; Maria Beatriz Bergonse Pereira Pedriali; Ricardo Danil Guiraldo; Sandrine Bittencourt Berger; Sandra Kiss Moura; Rodrigo Varella de de Carvalho Journal: J Conserv Dent Date: 2016 Nov-Dec