Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials.
OBJECTIVE
Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems.


METHODS
Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging.


RESULTS
The effects of aging on color parameters were statistically significant (p < 0.001), regardless of core thickness. For all systems, the CIE a* values increased as the thickness of the core increased. Conversely, such increases in core porcelain thickness were correlated with decreasing CIE L* and b* values. Core thickness had a statistically significant effect on color change among the groups.


CONCLUSIONS
Different core thicknesses (from 1.0-0.5 mm) and artificial aging affected color stability of the all-ceramic materials tested.
Department of Prosthodontics, Corlu Military Hospital , Tekirdag , Turkey.
Sibel
S
Dikicier
Simel
S
Ayyildiz
Julide
J
Ozen
Cumhur
C
Sipahi
D002516:Ceramics / Q000737:chemistry*; D003116:Color; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D003801:Dental Veneers; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation*; D013053:Spectrophotometry; D013499:Surface Properties; D013997:Time Factors; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
D003764:Dental Materials; C508050:IPS e.max Press; C483026:In-Ceram Alumina; C493120:lithia disilicate; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; C023506:Glass ceramics; D015040:Zirconium
aging; all-ceramic; color; core thickness