Methods: Fifteen specimens of enamel-MACOR® treated with Bioglass 45S5* (SS), aluminum tri-oxide** (AO) and Na-bicarbonate** (BS) were analysed using confocal (CLSM) and atomic force (AFM) microscopy for micro-and nano-roughness changes. A confocal laser microscope (Leica SP2 CLSM, Germany) equipped with a 20x, 1.4 NA oil immersion lens and a 514 nm argon/helium ion laser was used to examine the specimens in five different positions with a basic field of view of 750µm×750µm. The surface images were plane fitted into a 3D-thopograpich images and noise was filtered with a Gaussian filter. Configuration of the system was standardised for the entire experiment. The micro-roughness measurements were analysed using the image-processing software (Leica, Heidelberg, Germany). The same specimens were then analysed for nano-roughness evaluation using an AFM (Nanoscope III, Digital Instruments, Veeco, USA) with a basic field of view of 20µm×20µm. Five measurements were obtained from each surface and the data were analysed using the image-processing software (V530R35R Nanoscope). AFM and CLSM data were analysed statistically using the Mann-Whitney and the Kruskal-Wallis tests to assess the significance
Results: The roughness obtained with AO was significantly higher (p<0.05) then when BS and SS were used. BS and SS induced no significant changes compared to the untreated control surfaces (p> 0.05). The powder AO produced the greatest change on enamel profilomety. BS and SS produced similar profilometric changes (p> 0.05).
Conclusions: The air-polishing performed using SS and BS does not alter the roughness of the enamel during air-polishing procedures. [(*OSspray ltd, London, UK); (**DENTSPLY ltd, Addlestone, UK)].