title: Analysis of the color alteration and radiopacity promoted by bismuth oxide in calcium silicate cement.
abstract: The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC) was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO), determined by weight. Mineral trioxide aggregate (MTA) was the control group. The radiopacity test was performed according to ISO 6876/2001. The color was evaluated using the CIE system. The assessments were performed after 24 hours, 7 and 30 days of setting time, using a spectrophotometer to obtain the ΔE, Δa, Δb and ΔL values. The statistical analyses were performed using the Kruskal-Wallis/Dunn and ANOVA/Tukey tests (p<0.05). The cements in which bismuth oxide was added showed radiopacity corresponding to the ISO recommendations (>3 mm equivalent of Al). The MTA group was statistically similar to the CSC/30% BO group (p>0.05). In regard to color, the increase of bismuth oxide resulted in a decrease in the ΔE value of the calcium silicate cement. The CSC group presented statistically higher ΔE values than the CSC/50% BO group (p<0.05). The comparison between 24 hours and 7 days showed higher ΔE for the MTA group, with statistical differences for the CSC/15% BO and CSC/50% BO groups (p<0.05). After 30 days, CSC showed statistically higher ΔE values than CSC/30% BO and CSC/50% BO (p<0.05). In conclusion, the increase in radiopacity provided by bismuth oxide has no relation to the color alteration of calcium silicate-based cements.
authors.affiliation: Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, Universidade de São Paulo-USP, Bauru, SP, Brazil. marinangelica@usp.br
authors.forename: Marina Angélica
authors.initials: MA
authors.lastname: Marciano
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela
authors.forename: Rafael Francisco Lia
authors.initials: RF
authors.lastname: Mondelli
authors.forename: Ronald
authors.initials: R
authors.lastname: Ordinola-Zapata
authors.forename: Marco Antonio Hungaro
authors.initials: MA
authors.lastname: Duarte
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D000704:Analysis of Variance; D001729:Bismuth / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D003116:Color; D003738:Dental Cements / Q000737:chemistry*; D004338:Drug Combinations; D006801:Humans; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry; D017797:Prosthesis Coloring; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013997:Time Factors; D014075:Tooth Discoloration
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C033301:bismuth oxide; C031293:calcium silicate; D001729:Bismuth