PENGARUH BAHAN BLEACHING IN-OFFICE TERHADAP PERUBAHAN KEKASARAN PERMUKAAN RESIN KOMPOSIT BULK FILL VISKOSITAS TINGGI DAN NANOFIL

In-office bleaching is one of a dental treatment that used to get back the colour of the discoloured teeth which applied by the dentist in the dentist�s office. Patient who need bleaching treatment, sometimes has already had composite resin restoration on their teeth. Composite resin have different types, such as bulk fill with high viscosity and nanofil composite resins. This research was conducted to determine changes in surface roughness after the procedure of in office bleaching on bulk fill with high viscosity and nanofil composite resin restorations. Thirty two cylinder-shaped specimens (5x2 mm) were prepared from each of the following materials: sixteen bulk fill with high viscosity composite resins and sixteen nanofil composite resins. Subjects was soaked in artificial saliva and put into incubator for 24 hours at 37 0 C. The initial surface roughness of composite resins were measured with a surface roughness measuring instrument (Surfcom 120A). After initial surface roughness measurement, subjects were applied with bleaching agent 40% hydrogen peroxide (Opalescense Boost, USA). Then, the final surface roughness were measured and the surface roughness change value was calculated. Data were analyzed using independent t-test at a 95% confidence level (α=0,05). The mean level in group I and II respectively 0,0662 ± 0,02705 µm and 0,0475 ± 0,02295 µm. T-test showed that there were difference in surface roughness change between bulk fill with high viscosity and nanofil composite resins (p