Influence of Human Blood Contamination on Microhardness of Glass-Ionomer Cements and Glass-Hybrid Material

Objectives: The objective of this study was to investigate microhardness of high-viscosity and resin-modified glass-ionomer cement (GIC) and glass-hybrid material, with and without protective coating, after exposure to human blood before and after hardening of the material.
Methods: Twelve experimental groups (n=10 per group) were prepared. For four control groups (1. Fuji IX GP Extra, 2. Fuji II LC, 3. EQUIA Forte HT and 4. EQUIA Forte HT + EQUIA Forte Coat), materials were mixed and placed into teflon molds (5mm x 2mm). In four groups, identical to the control groups, samples were exposed to human blood for 10 minutes after hardening. In last four experimental groups, materials were exposed to human blood before hardening. The microhardness of the samples was measured in Vickers microhardness tester before and after thermocycling for 10 000 cycles and data obtained was statistically analyzed (Kolmogorov-Smirnov test, ANOVA, Scheffe’s test).
Results: In the control groups, the highest microhardness was measured for EQUIA Forte HT + EQUIA Forte Coat before thermocycling (70.71±8.79) and after thermocycling (68.6±7.65), (p<0.05). Before thermocycling, Fuji II LC samples exposed to blood before hardening had the lowest microhardness (42.65±4.22), (p=0.01), for Fuji IX GP Extra and EQUIA Forte HT, the highest microhardness was measured in samples exposed to blood after hardening (p<0.01). After thermocycling, EQUIA Forte HT+EQUIA Forte Coat showed the highest microhardness in the group exposed to blood after hardening (73.07±8.85), (p<0.05).
Conclusions: Exposure of the material to human blood before hardening negatively affected the microhardness of resin-modified, high-viscosity GIC and glass-hybrid material with protective coating. Exposure of the material to human blood after hardening, increased the microhardness of high-viscosity GIC and glass-hybrid material without protective coating. When materials were aged, microhardness of the samples increased after exposure to human blood after hardening for high-viscosity GIC and glass-hybrid material with protective coating.