Metallization and Ar-O plasma effects on dental enamel roughness evaluated with SEM and MeX™ for 3D reconstruction.

The MeX™ software is a useful tool for tridimensional data collection for surface evaluation and could be relevant to evaluate the same specimen in different phases of the study, assuming repeated measures of dental enamel roughness. The aim of this study was to evaluate the influence of sample metallization for dental enamel roughness analysis with 3D images reconstructed using MeX™ software from Scanning Electron Microscopy (SEM) images. The influence of 74.98% (%mol/mol) argon-oxygen plasma for carbon layer removal on surface roughness of the metallized specimen was also evaluated. Dental enamel specimens were prepared for SEM analysis with and without carbon metallization using conventional or environmental modes. Argon-oxygen plasma for carbon layer removal was used and surface roughness was re-evaluated. Roughness obtained by SEM and MeX™ reconstructed images, with or without metallization, did not differ. No significant alteration on surface roughness after carbon layer removal using plasma was found. SEM baseline evaluation using conventional mode without sample preparation and in environmental mode were not comparable. Roughness of enamel 3D images reconstructed with MeX™ software from SEM images, with or without metallization was similar. The 74.98% (%mol/mol) argon-oxygen plasma removed the carbon layer with no effect on enamel roughness.

Effect of surface treatments on staining and roughness of bleached enamel.

BACKGROUND: The objectives were to evaluate the effect of surface treatments and waiting time before contact with dye on bleached enamel staining and surface treatments on roughness. METHODS: One hundred bleached teeth were randomly assigned to G1 artificial saliva, G2 2% sodium fluoride (Flugel, Nova DFL), G3 casein phosphopeptide-amorphous calcium phosphate fluoride paste (MI Paste Plus, GC America), G4 rinse for bleached color maintenance (Keep White Rinse, DMC), and G5 polishing with impregnated disks (SuperBuff Disk, Shofu). Fifty specimens were immersed in coffee immediately after treatment; the others 1 h after. Color difference (ΔE) was evaluated with a spectrophotometer (Vita EasyShade) and roughness (Ra, Rq) with an optical profilometer (NewView 7300). Effects were analyzed with two-way ANOVA, Friedman, and Kruskal-Wallis test (P < 0.05). RESULTS: Surface treatments (P = 0.878), waiting time (P = 0.105), and interaction (P = 0.145) were not significant to bleached color maintenance. Roughness was different among the evaluation time points (2nd evaluation >1st evaluation >3rd evaluation) (P < 0.001); not among surface treatments (G1, G2, G3, G4, G5) (P > 0.05). CONCLUSIONS: Surface treatments were similar to saliva for bleached enamel color maintenance. Immediate or 1-h postponed contact with coffee did not affect bleached enamel color. Bleaching increased enamel roughness; surface treatments and artificial saliva decreased it.