Assessment of Capability of Lithium Disilicate Glass Ceramics to Reproduce the A2 Shade and to Mask A4 Substrates

Abstract

Aim: Capability of lithium disilicate glass ceramics to reproduce the A2 shade and to mask A4 substrates.Materials and Method: 32 lithium disilicate ceramic specimens were classified materials into 8 groupsof 4 each. Group I- III high translucency (HT) monolayer discs, group IV- VI had low translucency (LT)monolayer discs, group VII- VIII had medium translucency (MO) bilayer discs. A2 shade tab shade guide(VITA classical A1-D4) was used for CIE L*a*b* measurements of control. Color differences using thresholdswas as follows: for imperceptible (?E < 1.0), perceptible (1.0 < ?E < 3.3), and clinically unacceptable (?E> 3.3) differences.Results: ?E in group IV exhibited highest (9.92±0.21) and group III lowest (8.08± 0.25) value. When thecomplex was compared to the A4 substrate, significant difference among all groups (p < 0.05) was found.?E values when the complex was compared to the A2 shade tab, group III exhibited highest (4.82±0.16)and group V lowest (0.72±0.06) value. In groups I specimens had acceptable differences, group II hadperceptible differences, group III had perceptible differences, group IV had acceptable differences, group Vhad imperceptible differences, group VI and VII had acceptable differences and group VIII had imperceptibledifferences.Conclusion: Authors suggested to use LT ceramics with less thickness in the range of 0.5 mm- 0.7 mm tomask discoloration.