Atomic force microscopy analysis of different surface treatments of titanium

INTRODUCTION:The quality of the implant surface is very important to osseointegration, to the healing time, to tissue regeneration. The surface characterization of medical and dental materials has been conducted with the use of atomic force microscopy (AFM) in areas that range from biological crystal growth analysis to osseintegration of dental and medical implants. OBJECTIVES:To compare the morphology, roughness, and surface area of the samples, submitted to mechanically-induced erosion, chemical etching and a combination of both. MATERIALS AND METHODS:Titanium disks were preparated from 2 mm thick sheets of grade 2 unalloyed titanium. The disks had a diameter of 12 mm. The samples were polished to obtain a mirror finish surface were modified by either chemical etching or blasting. Four surfaces were investigated: machined (control), acid etched with hydrofluoric acid HF at 10% concentration for 10 minutes, blasted with Al₂O₃ particles of 110 µm, blasted and acid etched, all samples were submitted to chemical passivation using nitric acid (HNO₃ ) baths. The surface topography was performed with a atomic force microscopy (AFM), and the reported parameters were the average roughness (R_a), the RMS roughness (R_q), maximum vertical distance between the highest and lowest data points in the image (R_max), surface area. RESULTS:The averages parameters and areas for different surface treatments are the following: Machined:R_a140±0.025 µm, R_q179.4±0.015 µm, R_max 1807±0.1, area 2539.2 µm². Acid etched:R_a208±0.060, R_q268.6±0.039, R_max2753±0.15, area 2761.9 µm². Al₂O₃ blasted:R_a860.6±0.042, R_q1022±0.055, R_max4763±0.053, area 2892.0 µm². Al₂O₃ blasted and acid etched:R_a1370±0.096, R_q1639±0.1, R_max8005±0.069, area 3339.4 µm². CONCLUSIONS:The surface treatments have a strongly influence in the physical properties of samples. The surfaces that have undergone at Al₂O₃ blast and acid attack treatment present a higher area compared to those that were machined and chemically etched.