Evaluation of the changes in the surface properties and bacterial retention of four different restorative materials with fluoride after tooth brushing simulator

Purpose: The aim of this study is to evaluate the surface roughness and bacterial adhesion of four different restorative materials that can be applied in one step and release high fluoride, at the beginning, after polishing and after brushing simulator. Method: In our study, four main groups were formed according to the restorative materials used; alkacid (CN), Hybrid glass ionomer cement (Eq), zinc-containing high viscosity glass ionomer cement (CR), and resin modified glass ionomer cement (Fj). According to the procedures applied these groups were also divided into 3 subgroups [control (K), polishing (P) and brushing (F) (n=12)]; An additional subgroup was created in the Eq group [varnish (V) (n=12)]. Samples of 6 mm diameter and 2 mm height were prepared from all subgroups, no surface treatment was applied to the control group, only polishing was applied to the polishing group, brushing was applied to the brushing group after polishing, and brushing was applied to the varnish group after the surface coating was applied. Surface roughness was measured with a profilometer device in all samples, and surface topography with AFM device, micro-imaging of the material surface and elemental content were evaluated with SEM-EDX in 2 samples from each group. Polymicrobial biofilm was formed on 10 samples from each group, the resulting biofilm in 2 samples from each group was evaluated by imaging with Confocal Scanning Laser Microscope. Total bacteria, S. mitis and S. mutans colony counts were determined and the obtained data were compared. Results: Surface roughness values ​​were measured highest in the Eq-V group and there was a statistically significant difference between this group and all other groups (p<0.05). There was no difference between the other groups in terms of surface roughness values ​​(p>0.05). The lowest surface roughness values ​​were obtained from the polishing groups of all materials. It was observed that brushing application increased the roughness in all materials, except for the Eq-V group. There was no correlation between the surface roughness values of the materials and the number of microorganisms (p>0.05). There was no statistically significant relationship between the groups in terms of total bacteria and S.mitis colony numbers (p>0.05). The lowest S. mutans colony numbers were obtained from the CN groups, and the highest numbers were observed in the Eq-K, Eq-P and CR-F groups. Conclusion: It was determined that polishing and brushing applications caused changes on the surface of all materials. No direct relationship was found between surface roughness and bacterial colonization. It is seen that the use of Cention-N material may be advantageous especially in terms of the involvement of S.mutans microorganism. Keywords: Surface roughness, polymicrobial biofilm, S.mutans