The influence of surface finish and in-vitro pellicle on contact-angle measurement and surface morphology of three commercially available composite restoratives.

Three commercially available composites (Concise, Occlusin and Heliomolar) had surface finishes of varying roughness. Concise and Occlusin were cured against glass and Mylar, or were polished with a white stone or Soflex discs, producing four different surface finishes. Heliomolar was cured against glass or finished with a Vivadent polisher. Each specimen was immersed in water (without pellicle) or artificial saliva (with pellicle) and photographed with a captive air bubble. The influence of pellicle on contact-angle measurements and hence adhesiveness was determined. Scanning electron microscopy of pellicle-free and pellicle-conditioned surfaces was also performed. The effect of the pellicle on all Concise specimens was profound, tending to increase adhesiveness of the smooth (glass and Mylar) surfaces and decrease adhesiveness of the roughened (white stone and Soflex disc) polished surfaces. The pellicle-conditioned smooth Occlusin surfaces behaved similarly, but not the polished specimens, having similar contact-angle measurements after pellicle deposition. Heliomolar had significantly reduced contact-angle measurements after pellicle formation, and thus increased adhesiveness. The influence of the pellicle on surface finish characteristics may be significant, and may vary according to the composite used.