Abstract
Objective The aim of this study was to determine the effect of two acidic beverages (orange
juice and H3PO4-containing fizzy drink) on the surface topography and color stability of two commonly
used computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials.
Materials and Methods Sixty samples of two CAD/CAM ceramic materials, lithium disilicate (IPS e-max CAD)
and zirconia reinforced lithium silicate (Vita Suprinity), were prepared according
to the manufacturer's instructions. The samples were immersed in one of three media
(artificial saliva, orange juice and H3PO4-containing fizzy drink) and then stored in an incubator at 37 °C for 24 hours). Before
and after immersion in different media, the surface roughness (Ra) of the samples
was assessed using profilometer (JITAI8101 Surface Roughness Tester—Beijing Jitai
Tech Detection Device Co. Ltd, China) and the color parameters were measured using
VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). Surface topography was
observed using scanning electron microscope (SEM) and surface mineral content was
compared before and after immersion. Paired sample t-test was used to determine the change in Ra before and after immersion. Two-way analysis
of variance was used to determine the effect of different CAD/CAM materials and immersion
media on the mean ∆Ra and mean ∆E of the studied groups. Tukey's honest significant
difference posthoc test was used for multiple comparisons at a level of significance
(α = 0.05).
Results A significant increase in Ra and a decrease in the color stability of the two investigated
ceramic materials were detected after immersion in the acidic media than in artificial
saliva. SEM and energy-dispersive X-ray results revealed the dissolution of the glassy
matrix and the exposure of silicate crystals.
Conclusion The surface topography and color stability of glass ceramics are affected by the
pH of different acidic media.
Keywords
acidic media - glass ceramics - surface roughness - color stability
