Effect of polishing systems on the surface roughness of microhybrid composites

Purpose : This study was undertaken to examine the effect of three different polishing systems on surface roughness of five newly developed resin composites.
Materials and Methods : Three microhybrid composites (Point 4™, Kerr, Orange, CA; Esthet-X™, Dentsply/Caulk, Milford, DE; Vitalescence®, Ultradent, South Jordan, UT, USA), one microfilled composite (Renamel Microfill®, Cosmedent, Chicago, IL, USA), and one experimental micro-hybrid composite (FZB, Ivoclar Vivadent, Schaan, Liechtenstein) were light cured with a Mylar strip. Fifteen specimens of each composite (6 mm in diameter and 3 mm in depth) were fabricated and randomly assigned to three groups. Specimens in each group were finished with a carbide bur (16 fluted) and three polishing systems (Astropol®, Ivoclar Vivadent; Diagloss®, Axis Dental, Irving, TX, USA; Sof-Lex™, 3M, ESPE, St. Paul, MN, USA). The average surface roughness (Ra) and the mean peak spacing (Sm) were measured with a surface profilometer after polishing. Five tracings at different locations on each specimen were made. Data were analyzed by analysis of variance.
Results : For Astropol, Ra ranged from 0.10 to 0.15 um and Sm ranged from 24 to 40 um for the five composites; for Diagloss, Ra ranged from 0.24 to 0.34 um and Sm from 38 to 74 urn; for Sof-Lex, Ra ranged from 0.06 to 0.10 um and Sm ranged from 16 to 22 um. Significant differences between materials and polishing systems were observed. Polishing systems had the most important role in determining the surface roughness of resin composites.
CLINICAL SIGNIFICANCE
Of the polished systems tested, Sof-Lex discs provided the lowest roughness for polishing microfilled and microhybrid composites, and the microfilied resin composite showed the lowest roughness.