Using Hydrofluoric Acid to Enhance Titanium Surface Topography

Purpose The aim was to explore the effect of different concentrations of HF acid etch on titanium surface topography (with different time interval). Materials and Methods Pure polished titanium discs were subjected to various concentration of HF acid etch (0.2 wt % and 0.5 wt %) for for four time intervals of 1.5 min, 2 min, 2.5 min and 3 min. at room temperature. After etching the discs were rinsed immediately with distilled water. Polished titanium surfaces were used as a control. Surface roughness was measured using profilometry. Topography was examined using scanning electron microscopy (SEM). Results Etching of titanium discs with 0.2 wt % or 0.5 wt % HF acid had a clearly visible effect on polished titanium surfaces. For etching with 0.5 wt % HF, a steady increase in Ra value with etching time was observed reaching a maximum value of 0.147 m at 3 min. Highly significant differences were found between Ra value in 3 min etching and both 1.5 and 2 min etching given in P= 0.001. For etching with 0.2 wt % of HF, a relatively different pattern was observed. The Ra values increased for 1.5 and 2 min acid exposure then slightly decreased at 2.5 min acid exposure before increasing again for a 3 min etching period. Highly significant differences were found between the 1.5 min group and both 2 min and 3 min group given P = 0.004, 0.001 respectively. SEM picture shows grain pattern (A honeycomb pattern) of the titanium surface following treatment with 0.5 wt % HF acid etching. Conclusions This research showed that a slight difference in concentration, or duration have significant impact on titanium surface topography. Titanium is an amenable material for designing of implant and it is possible to modify the surface using a variety of protocols. Roughness resulting from HF acid etching varied according to acid concentration, duration of acid etching procedure and original surface roughness of the substrate.