The effect of standardised implantoplasty protocol on titanium surface roughness: an in-vitro study

To analyse the changes of surface characteristics of machined and moderately roughened titanium disks following a standardised implantoplasty protocol. Forty titanium discs (machined: n = 20; moderately roughened: n = 20) were instrumented with one half of each disc maintained as the control (non-instrumented). The standardised implantoplasty protocol was carried out using a custom jig with the sequential change of burs: 1) Regular grit diamond [10s], 2) Super-fine grit diamond [10s], 3) Brownie(tm) silicone polisher [15s], 4) Greenie(tm) silicone polisher [15s]. Surface topography was analysed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Energy dispersive x-ray spectroscopy (EDS) was used to measure the elemental profiles of each disc. Quantitative analysis showed similar changes in level of roughness between the machined and moderately roughened titanium discs. CLSM demonstrated an increased roughness (Ra and Sa values) after polishing with a regular grit diamond bur when compared to the uninstrumented surfaces. Although the roughness decreased after the further polishing with the super-fine grit diamond bur, subsequent instrumentation using silicon burs tended to increase the roughness, albeit being statistically insignificant. There was a residue of silicon particles despite the irrigation after each polishing stage. The proposed implantoplasty protocol did not achieve a sufficient level of smoothness on the machined or moderately roughened titanium surfaces when compared to the Ra threshold. Further research is recommended to test the efficacy of each bur on titanium surfaces with longer duration using actual oral implants to allow better comparison.