Edge chipping and translucency comparison among lithium silicate‐based ceramics
Essa A. Alghamdi, Geoffrey A. Thompson, Shengtong Han, Jeffrey M. Toth, David W. BerzinsAbstract
Purpose
Lithium disilicate glass‐ceramics have excellent esthetic characteristics, but lack the strength of zirconia. Some newer lithium silicates now contain zirconia and are marketed as “zirconia‐reinforced” with the implication that they are improved in strength. The purpose of this study was to determine the edge chip resistance/toughness and translucency of lithium silicate–based glass‐ceramics.
Materials and Methods
Four lithium silicate/disilicate glass‐ceramic materials, IPS e.max CAD‐HT/MT and GC Initial LiSi‐HT/LT blocks, and two zirconia‐lithium silicate glass‐ceramic materials, VITA Suprinity PC and Celtra Duo, were tested ( N = 20/group). Specimens (14 × 12 × 1.5 mm) were sectioned from commercially available chairside CAD‐CAM blocks, fired (if indicated), ground, and polished. Translucency was assessed via a spectrophotometer. For edge chipping, specimens were adhered to a resin bed. Edge chips were produced using a 120‐degree sharp, diamond indenter mounted in a universal testing machine with the specimen's edge positioned at distances ranging from approximately 0.4 to 1 mm horizontally from the indenter tip. Translucency was compared with one‐way ANOVA and edge chipping was evaluated with regression and Kruskal–Wallis tests.
Results
Significant differences in translucency parameter (TP 00 ) were found between the materials ( p ≤ 0.001). The statistical ranking of the TP 00 was: GC Initial LiSi‐HT > IPS e.max CAD‐HT > Celtra Duo > GC Initial LiSi‐LT > VITA Suprinity PC = IPS e.max CAD‐MT. For edge chipping, VITA Suprinity PC and Celtra Duo had significantly ( p < 0.05) lower edge chip resistance ( R eA ) than IPS e.max CAD HT, but all other comparisons were not significant.
Conclusions
The incorporation of zirconia in lithium silicate glass‐ceramics did not result in superior edge chip resistance. Moreover, VITA Suprinity PC was more opaque than the other tested ceramics except IPS e.max CAD‐MT.