Influence of increment thickness on the similarity of composite shade: a pilot study.
The aim of this study was to evaluate the similarity in shade between increments of different composite thicknesses. Fifty test specimens 12 mm in diameter were fabricated and separated into five groups (n = 10) according to sample thickness: 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm. Specimens were polished with water abrasive papers and silicone points. Next, based on the CIE L*a*b* system, test specimens were submitted to color readouts, and the values obtained for the coordinates L*, a*, and b* for each thickness were compared using one-way ANOVA and a Tukey test (P < 0.05).  The results demonstrated that there was a reduction in coordinate L* as the test specimen thickness increased, with statistically significant differences (P < 0.05), except for 2.0 mm and 2.5 mm thicknesses (P > 0.05). Samples 1.5 mm thick presented less variation of a*, while a greater variation occurred for samples 2.5 mm thick, with a significant difference in comparison with the other thicknesses (P < 0.05), except for 2.0 mm (P > 0.05). Samples 0.5 mm thick presented a greater variation of b*, while the lowest variation in this coordinate occurred for samples 2.5 mm thick, which was significantly different from the other samples (P < 0.05). It was concluded that different composite thicknesses do not present similarity of color and have an influence on the final result of esthetic restorations.
Department of Dental Materials and Prosthodontics, Ribeirao Preto School of Dentistry, University of Sao Paulo, Brazil.
Lourenco de Moraes Rego
Lde M
Roselino
Lucas da Fonseca Roberti
Lda F
Garcia
Ana Beatriz Silva
AB
Sousa
Fernanda de Carvalho Panzeri
Fde C
Pires-de-Souza
D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008027:Light; D008422:Materials Testing; D010316:Particle Size; D055668:Photochemical Processes; D010865:Pilot Projects; D012828:Silicones / Q000737:chemistry; D013053:Spectrophotometry; D013499:Surface Properties
D003188:Composite Resins; D003764:Dental Materials; C444701:Filtek Z250; D012828:Silicones