In vitro investigation of antimicrobial effects, nanohardness, and cytotoxicity of different glass ionomer restorative materials in dentistry.

Aims: The aim of this in vitro study was to investigate the antimicrobial effects, nanohardness, and cytotoxicity of different glass-ionomer restorative materials in dentistry.

Materials and Methods: The following glass-ionomer restorative materials were used in our study: Argion (VOCO, Germany), Zirconomer (Shofu Inc., Japan), EQUIA Forte (GC, Japan), Fuji II LC capsule (GC, Japan), and Fuji IX GP capsule (GC, Japan). For the cytotoxicity test, a cell culture without release liquids was used as the control group. Microdilution and a disk diffusion test were used to measure the antimicrobial activity. The MTT (3- [4,5-dimethylthiazol-2-yl] -2,5-diphenyltetrazolium bromide) assay was used to evaluate cytotoxicity. Nanohardness was measured using a nanoindenter device.

Results: Our study determined that all restorative materials used in this study inhibited bacterial growth in cultures containing 1 × 102 cfu/ml of the bacterial concentrations (Lactobacillus casei and Streptococcus mutans) and that all restorative materials inhibited fungal growth in the cultures containing <1 × 102 cfu/ml of the fungal strains (Candida albicans). IC50 values obtained for the cytotoxicity test were analyzed using the Chi-square test. After a 72-h incubation period, Zirconomer, EQUIA Forte, Fuji IX GP capsule, and Fuji II LG capsule showed statistically significant lower cell viability values. (P < 0.05). The Kruskal-Wallis analysis was performed on the values obtained from the nanohardness test; the differences between the groups were found to be significant (P < 0.05).

Conclusions: All materials tested showed low antimicrobial activity, and the antifungal activity of these materials was found to be lower than their antimicrobial activity. Only Argion showed non-cytotoxic effect. Beginning with the group with the highest nanohardness values and ending with the lowest, the groups are ranked in the following order: Fuji II LC capsule, EQUIA Forte, Argion, Fuji IX GP capsule, and Zirconomer.