EFFECT OF LACTIC AND ACETIC ACIDS ON THE MICROHARDNESS OF TWO CERAMIC BASED NANOHYBRID COMPOSITES
The organic matrix of the resin-based composite (RBC) restoration in the subject is susceptible to degradation by acids. Newer RBC have incorporated organically modified ceramics into their formulations. The objective of the study was to document the effect of lactic and acetic acids on the microhardness values of two ceramic based nanohybrid composites (CBNC) after different immersion periods. This experimental laboratory-based study was conducted on 60 specimens, 30 in each of the two CBNCs (Tetric N-Ceram and Ceram-X). The test specimens were made in a standard split mold having dimensions of10 mm diameter and 2 mm thickness. The specimen was cured and the baseline Vickers hardness number (VHN) was measured and the remaining microhardness assessment was done after the various immersion periods of 2 days, 7 days and 21 days. The data were analyzed in statistical program (SPSS version 25.0). Descriptive statistics along with repeated measures ANOVA was used for the comparison of microhardness. The level of p-value to be significant was set as 0.05. The change in microhardness of both Tetric N-ceram (p=0.671) and Ceram-X (p=0.530) after baseline, 2 days, 7 days and 21 days after immersion in various media were statistically insignificant. It can be concluded that there was no effect of acids on surface microhardness of both test materials.