In vitro effects of erosive challenge on the surface properties of sealants

Aim: To assess in vitro the surface roughness (Ra), Vickers hardness (VHN) and surface morphology of resin and glass ionomer materials used for sealants after dynamic erosive challenge.
Methods: Twenty specimens of each material were prepared and divided into experimental (erosive challenge) and control groups (n=10): Protect Riva (SDI), Opallis Flow (3M ESPE), Fluroshield (Dentsply), Filtek Z350 XT Flow (3M ESPE). The erosive challenge was performed 4 times per day (90 s) in cola drink and for 2 h in artificial saliva for 7 days. The control specimens were maintained in artificial saliva. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was evaluated by scanning electron microscopy (SEM). The data were analyzed by ANOVA, Tukey and paired t tests (α=0.05).
Results: After erosion and saliva immersion, there was an increase in Ra values for all groups and Riva group showed the highest Ra values. After erosive challenge, Riva and Filtek groups showed significant decrease in VHN values, but Filtek group showed the greatest %VHN. For all groups there was inorganic particle protrusion and matrix degradation after erosion visualized by SEM images.
Conclusions: Erosive challenge affected the surface properties of all materials used as sealants, particularly in the Riva and Filtek groups.