Purpose: The purpose of this in vitro study was to evaluate the effect of simulated gastric acidity on surface roughness of different types of dental ceramics.
Methods: Fifty specimens were divided according to type of the material into five groups (n=10), as follows: Partially stabilized zirconia (PSZ) (Prettaue),Fully stabilized zirconia (FSZ) (Prettaue Anterior), lithium disilicate ceramics (IPS. Emax), Zirconia-containing lithium silicate ceramics (ZLS) (Vita Suprinity) and Hybrid ceramics (Vita Enamic). Specimens were cut using a low-speed diamond saw (Isomet) into a rectangular shape with the following dimension: 12mm width x 14mm length x 1 mm thickness. Surface roughness was evaluated by optical profilometer. Each specimen was immersed in 5 ml of the simulated acid of ph 1.2 for 96 h in a37◦C incubator. Surface roughness of all tested groups was revaluated. One-way ANOVA was used to compare mean difference between groups. Paired t-test was used for comparing (before and after) roughness in each group.
Results: There was significant difference (P=0.002) between all groups. There was increase in surface roughness for all materials tested, but it was non-significant (P>0.05) for Prettaue (P=0.607), Prettaue Anterior (P=0.273) and Vita Suprinty group (P=0.201). There was significant increase (P≤0. 05) for IPS. Emax group (P=0.007) and Vita Enamic groups (P=0.021). Prettaue Anterior group showed the least amount of surface roughness change (0.0006±0.002), while Vita Enamic group showed the highest surface roughness change (0.0100±0.011).
Conclusions: The gastric acid significantly increased the surface roughness of hybrid ceramics and lithium disilicate ceramics