Surface geometry of three packable and one hybrid composite after finishing

This study compared the effects of different finishing techniques on the surface of a traditional hybrid composite and three packable composites. Four composites were used in the study (Herculite XRV/Kerr, Definite/Degussa, SureFil/Dentsply and Solitaire/Heraeus-Kulzer). Fifty specimens were made of each material, sized 7 x 7 x 4 mm. Fifteen specimens of each material were subjected to the following finishing procedures: (1) a 30 microm diamond, (2) a 30 microm and a 20 microm diamond and (3) a 30 pm diamond followed by a tungsten carbide finishing bur. As a reference, five specimens of each material were treated by Sof-Lex discs (3M). For quantitative surface evaluation, laser-stylus profilometry was used. Roughness parameters included average roughness (Ra) and profile-length-ratio (LR). Statistical analysis was performed with one- and two-way Anova and Scheffé post-hoc tests. Qualitative surface evaluation in SEM was performed at a tension of 25kV. Significant effects were found with both the composites and the finishing methods with respect to surface roughness (p < 0.001 for Ra and LR). A 30 microm diamond caused the greatest roughness on all composites, with Ra ranging from 2.015-2.079 microm (p<0.001). After finishing using methods 2 and 3, the Solitaire surfaces were significantly smoother (p < 0.001 for LR). The lowest roughness values were achieved after using disks; again, the Solitaire specimens yielded the lowest Ra and LR values (p < 0.001 except for Sure-Fil). With scanning electron microscopy, surface areas with signs of destruction were found after using a 30 microm diamond on Definite specimens.