Effects of Two Different Mediums on Different Restorative Materials

Objectives: The aim of this study was to evaluate effects of water and cola on color stability, surface-roughness, microhardness, sorption and solubility of five different restorative materials.
Methods: Disc-shaped specimens (2mm thickness x 10mm diameter) were prepared for each material; giomer (Beautifil II, Shofu, Kyoto, Japan), bioactive resin-modified glass-ionomer cement (B-RMGIC) (Activa Bioactive, Pulpdent, Watertown, MA, USA), glass-carbomer (GCP Dental, Ridderkerk, Netherlands), high-viscosity glass-ionomer (Ketac-Molar, 3M-ESPE, Dental Products, St. Paul, MN, USA) and nanohybrid-composite (Filtek Z250, 3M-ESPE, Dental Products, St. Paul, MN, USA) (n=14). Baseline color (CIELab), mass (gr), microhardness (VHN) and surface-roughness (Ra) values were measured and specimens immersed in distilled water and cola for 28 days. Color, mass, surface-roughness and microhardness values were remeasured following immersion and color change (ΔE), sorption (%) and solubility (%) values were calculated for both mediums. Data were analyzed with two-way ANOVA and Tukey’s-HSD, Tamhane’s-T2 post hoc tests. Student-T, Paired-Sample-T and one-way ANOVA tests were performed (p<0.05).
Results: Color change, surface-roughness, microhardness, sorption and solubility values varied significantly among tested materials. B-RMGIC exhibited the lowest microhardness values (p<0.01), while high-viscosity glass-ionomer exhibited significantly higher surface-roughness values after immersion in both mediums (p<0.01). All groups demonstrated higher color-change values when immersed in cola compared to water (p<0.05). Nanohybrid-composite exhibited the highest color stability when immersed in cola and lowest sorption values in both mediums (p<0.01). Glass-ionomer exhibited significantly higher solubility in both mediums (p<0.01).
Conclusions: Water and cola caused significant alterations in tested properties of the materials. Within the limitations of this study, nanohybrid-composite demonstrated better values in tested properties than those of the other materials in both mediums. It was also important to note that glass-carbomer and giomer demonstrated comparable values of surface roughness, microhardness, water sorption and solubility.