To evaluate the changes in enamel surface roughness and elemental concentrations following interproximal reduction (IPR), with and without polishing, in comparison with enamel without stripping. Selected premolars were randomly divided into a control group and four experimental groups; Group A (control): enamel without stripping, Group B: IPR with diamond bur, Group C: IPR with diamond disc, Group D: IPR with manual strip, Group E: IPR with mechanical oscillating strip. Each experimental group was divided into two subgroups where one subgroup was also polished with fine Sof-Lex discs. A total of 108 enamel samples (12 samples/subgroup and 12 samples for the control group) were used. Enamel was evaluated with atomic force microscope, energy-dispersive x-ray spectroscopy, and scanning electron microscope. The IPR produced higher average roughness (nm) in all groups compared with the enamel without stripping which measured 79.5 ± 17.4 nm. The only significant difference among the experimental groups was the higher roughness in the disc group compared to the oscillating strip group, p = 0.035. Polishing produced smoother enamel surfaces in all groups.The Ca/P weight (%) was 1.68 ± 0.45% when the enamel was not stripped and the ratio ranged from 2.03 ± 0.69% to 2.58 ± 0.47% in the IPR/IPR+polishing groups. Scanning electron microscope confirmed an increase in surface roughness following IPR with subsequent improvement after polishing. The IPR increased enamel surface roughness and affected the elements weight (%) and atomic (%). Polishing improved the surface quality. The IPR with oscillating strip followed by polishing with Sof-Lex strip produced the most favorable results.
Omar et al. (Mon,) studied this question.