مقايسه ي آزمايشگاهي ميزان زبري سطحي و مقاومت به سايش دو ماده ي سرومر بلگلاس و گراديا

An Invitro Comparative Study on Abrasive Wear Resistance and Surface Roughness of two Ceromers: Belleglass and Gradia

Statement of problem: Surface changes of ceromers caused by tooth brushing are well established, meanwhile they have been improved and are now widely used for various kinds of prosthetics restorations. These materials have lower surface hardness than porcelain and may induce discoloration due to surface roughness. Since it is an important clinical problem, more investigations are needed to evaluate their surface roughness. Purpose: The aim of this study was to evaluate the effect of tooth brushing on abrasive wear and surface roughness of two current used ceromers. Material and method: Ten specimens of each type of the ceromer (Belleglass and Gradia) were prepared. All the specimens were examined and surface roughness (Ra) of each was recorded. Then tooth brushing abrasion test were performed with 500 gr weight applied, using a dentifrice containing calcium carbonate as the abrasive material. The surface roughness of each specimen after 20000 strokes were determined with Talysurf 10. Data were analyzed with two sample T test and non parametric Wilcoxon test. Results: Mechanical toothbrushing decreased the surface roughness of Gradia (p<0.05), but did not have any effect on the surface roughness of Belleglass (p>0.05). Conclusion: The results of this study showed that Belleglass is more resistant to abrasive wear but Gradia is a more polishable ceromer.