Effect of polishing systems on the surface roughness of microhybrid composites.
OBJECTIVE
This study was undertaken to examine the effect of three different polishing systems on surface roughness of five newly developed resin composites.


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 microhybrid 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 microm and Sm ranged from 24 to 40 microm for the five composites; for Diagloss, Ra ranged from 0.24 to 0.34 microm and Sm from 38 to 74 pm; for Sof-Lex, Ra ranged from 0.06 to 0.10 microm and Sm ranged from 16 to 22 microm. Significant differences between materials and polishing systems were observed. Polishing systems had the most important role in determining the surface roughness of resin composites.


CONCLUSIONS
Of the polished systems tested, Sof-Lex discs provided the lowest roughness for polishing microfilled and microhybrid composites, and the microfilled resin composite showed the lowest roughness.
Lu
Huan
H
Houston Biomaterials Research Center, Department of Restorative Dentistry and Biomaterials, University of Texas Health Science Center at Houston, Dental Branch, Houston, TX 77030-3402, USA. huan.lu@uth.tmc.edu
Roeder
Leslie B
LB
Powers
John M
JM
D000704:Analysis of Variance; D002244:Carbon; D003188:Composite Resins / Q000737:chemistry*; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011109:Polymethacrylic Acids / Q000737:chemistry; D013499:Surface Properties
D003188:Composite Resins; C466112:Esthet-X; D011109:Polymethacrylic Acids; C452440:Vitalescence composite resin; C451741:point 4 composite resin; C444445:renamel microfill; D002244:Carbon