Fig 7. SEM and acquired elemental maps from EDS analysis.

A, B: machined surfaces (titanium displayed in red) showed sparse, dark-gray islets made of carbon (in green) that can be regarded as residues of the machining procedures, incompletely removed by subsequent cleansing. C, D: grit-blasted specimens examined after biofilm formation (highlighted by carbon presence, in red) showed aluminum traces (blue, arrows) corresponding to alumina particles embedded into the titanium surface (green) and still present after biofilm formation. E, F: Enamel surfaces (calcium in green) covered by biofilm structures (carbon in red). No contaminating agents derived from polishing procedures can be observed. G, H: high magnification of grit-blasted and laser-treated specimens, respectively, after biofilm formation. In laser-treated specimens, microorganisms show a colonization pattern where cocci, bacilli and extracellular matrix residues can be found on the edges of the pits. Reduced or no biofilm formation can be seen in the inner part of the pits, which were mostly colonized by streptococcal forms.