Methods: Environmental scanning electron microscopy (ESEM) was used to investigate surface topography as it enabled direct observations without metallization. Four groups of five specimen discs were prepared as followed: (group 1) no treatment, (group 2) carbide bur treatment, (group 3) soft brush wheel-mandrel mounted treatment, (group 4) perfectly polished. All specimens were viewed with a Philips XL30 ESEM (FEI Company) equipped with a lanthanum hexaboride (LaB6) electron gun and a gaseous secondary electron detector.
Results: Here we demonstrate that polishing such a “composite” material gives a homogeneous surface. For group 4 specimens, only glass charges were visible whereas bead polymerates had totally disappeared. For the 3 other groups, the topography observation showed both elements.
Conclusion: this new type of direct cold-cure relining based on composite technology needs a perfect polishing treatment to avoid roughness and therefore micro-organisms adhesion.