In-vitro assessment of the effect of surface coating on different glass ionomer restorative materials on the biofilm formation and secondary caries

The aim of this study was to in vitro evaluate the effect of applying surface coating agent (Equia Forte Coat/GC) on three different glass ionomer restorative materials (Ketac Molar Easymix/3M, ChemFil Rock/Dentsplay, Equia Forte/GC) on biofilm formation and secondary caries. For each of the two experiments carried out in the study, 3 surface coated experimental and 3 surface uncoated control groups were formed with 8 samples for each material. The Streptococcus mutans biofilm on the materials was measured by the colony forming unit (cfu) method. One sample of each group was imaged with a Scanning Electron Microscope (SEM). For the secondary caries test, prepared teeth were placed in the demineralization solution and images were taken with a stereomicroscope for analysis. In this study statistical analysis was performed with Kruskal Wallis test, Dunn's multiple comparison test, Mann-Whitney-U test, chi-square test. The results were evaluated as p<0.05 significance. The quantity of S.mutans biofilm formation of the coated subgroup of Equia Forte material were statistically significantly lower than the coated subgroup of ChemFil Rock material (p<0.05). There was no statistically significant difference between the other study groups (p>0.05). The B type lesion values of coated subgroup of ChemFil Rock material was significantly higher than the other coated subgroups. There was no statistically significant difference between the A, C and D type lesion values ​​of the groups in the evaluation of the secondary caries (p>0.05). As a conclusion, it is determined that surface coating application on glass ionomer restorative materials does not have a significant effect on S.mutans biofilm formation and secondary caries. It is suggested that the surface coating agent should be applied on glass ionomer materials.