ADRIANA BALAN, ANDREI-VICTOR SANDU, SIMONA STOLERIU, VERONICA SERBAN PINTILICIUC, VASILICA TOMA EFFECT OF DIFFERENT FINISHING AND POLISHING SYSTEMS ON THE SURFACE ROUGHNESS OF COMPOSITE RESINS The aim of the study was to compare using atomic force microscopy the surface roughness of three types of composite resins after finishing and polishing procedure with three different systems. A hybrid (Valux Plus, 3M ESPE), a microhybrid (Filtek Z 250, 3M ESPE) and a nonohybrid (Herculite XRV Ultra, Kerr) composite resins were chosen for this study. A number of 28 samples having 10 mm in long ,7 mm in width and 2 mm in high of each composite resin were obtained. The samples were equally split in 4 groups. In control group 7 specimens of each material received no finishing and polishing treatment after being cured under plastic matrix strip. In the first study group 7 samples of each material were finished using fine, safe end taper tungsten carbide bur, 7 samples were finished using superfine needle diamond bur and 7 samples used diamond impregnated one stage polisher. The surface of all composite samples was analyzed using atomic force microscopy. The results were expressed as root mean square surface roughness (nm). The results were statistically analysed using ANOVA and post hoc Bonferroni test at a 0.5 significance level. Significantly differences were obtained in the surface roughness of all three tested composite resins after finishing and polishing when comparing to surface roughness from control group. The one-step diamond abrasive polisher leaded to a significant lower surface roughness for all three composite resins when comparing to the surface roughness when tungsten carbide bur or diamond bur were used. Surface roughness of Valux Plus was higher than that observed for Filtek Z 250 or Herculite XRV Ultra, irrespective of the system used for finishing and polishing. The surface roughness of composite resins is in relation with the type of composite resin and the type of finishing and polishing system. The one-step diamond abrasive polisher was more efficient in obtaining smooth surface when comparing to tungsten carbide bur or diamond bur. The nanohybrid composite resin has a lower surface roughness when comparing to microhybrid and the hybrid composite resin after finishing and polishing.
Keywords: composite resins, surface roughness, AFM, finishing and polishing system