Efficacity of Two Polishing Systems

Objectives: The aim of this laboratory study was to evaluate the polishing efficacy of two polishing system (one for resin composite, a second for ceramic) on two different composite resins (a mycrohybrid and a nanohybrid composite).

Methods: A microhybrid composite Herculite XRV® (Kerr) and a nano-hybrid composite Filtek Supreme® (3M) were polished using Sof-Lex® (3M) and StarTec® (Edenta). Four groups of 3 cylinders of 9 pits were performed. For 2 groups, (2 x n=9), pits were filled with Herculite XRV® et for 2 others with Filtek Supreme®. Then, they were light-cured (VALO), for 40s. All sample were polished with coarse and medium disc of Sof-Lex® (3M) for 10s, at 10 000 tr/min. For each composite, a group was polished by fine and super fine discs of Sof-Lex® (3M) and a second by StarTec® (Edenta), for 20s, at 15 000 tr/min. The surface of each sample were quantitatively evaluated by surface roughness and qualitatively evaluated by optical microscope (OM) and scanning electron microscopy (SEM).
Results: For both composite, surface roughness after polishing were significantly lower with Sof-Lex® than with Starctec®. Surface roughnes of Herculite was lower than that of Filtek, whatever the polishing system used. For Filtek Supreme, SEM observations showed more regular bands with StarTec than with Sof-Lex, but the global surface seemed to be smoother with Sof-Lex. For Herculite XRV, no band were observed at SEM with Sof-Lex, but fine bands with StarTec.

Conclusions: Whatever the composite, OM showed smoother and glosser surface with StarTec, while surface roughness was lower with système Sof-Lex®. StarTec could be adapted for polishing of resin composite. Clinical evalution of composite resin' s surface was not directly related to surface roughness.