IADR Abstract Archives
Titanium-Zirconium for Oral Implants: Comparison of Mechanical Properties with Titanium
Objectives: Titanium (Ti) has been widely accepted as biomaterial for orthopaedic and dental implants. It has been suggested that titanium-zirconium alloy (TiZr) has better mechanical properties than pure Ti, However, there are very few published reports on the mechanical properties of titanium when alloyed with 13-17% of zirconium. The objective of this study was to compare the mechanical properties (modulus of elasticity and hardness) of the TiZr, Ti and a proprietary TiZr implant material, Roxolid® (Straumann, Switzerland), using nanoindentation.
Methods: Five disks (10mm diameter x 1.5mm thickness) were cut from pure Ti (grade IV) and TiZr (Zr 13-17 wt %) rod. The Ti, TiZr and Roxolid® implant were embedded, sequentially ground, polished and cleaned. The specimens were subjected to nanoindentation using an Ultra Micro-Indentation System with a calibrated Berkovich indenter and a compliance correction of 0.0002 μm/N. Twenty-five indentations per sample (n = 25) were performed using a load of 200 mN with 50 μm spacing between indents. The Poisson’s ratio (0.37), required to calculate the hardness and elastic modulus, was standardised across the three materials and post-data analysis of the elastic modulus and hardness was performed using the IBIS 2 nanoindentation system software.
Results: The TiZr and Roxolid® were found to have significantly lower elastic modulus values than Ti (p<0.0001, one-way ANOVA). However, there was no statistically significant difference between the TiZr and Roxolid® (p= 0.8712, ANOVA) values. Both TiZr alloys had significantly higher (p<0.05) hardness than Ti with no significant difference between them.
Conclusions: A lower elastic modulus and significantly higher hardness for both TiZr and Roxolid® make them stronger biomaterial suitable for high load bearing implants. The results show that TiZr rod used in this study was sufficiently similar to Roxolid implants with respect to mechanical properties.
Methods: Five disks (10mm diameter x 1.5mm thickness) were cut from pure Ti (grade IV) and TiZr (Zr 13-17 wt %) rod. The Ti, TiZr and Roxolid® implant were embedded, sequentially ground, polished and cleaned. The specimens were subjected to nanoindentation using an Ultra Micro-Indentation System with a calibrated Berkovich indenter and a compliance correction of 0.0002 μm/N. Twenty-five indentations per sample (n = 25) were performed using a load of 200 mN with 50 μm spacing between indents. The Poisson’s ratio (0.37), required to calculate the hardness and elastic modulus, was standardised across the three materials and post-data analysis of the elastic modulus and hardness was performed using the IBIS 2 nanoindentation system software.
Results: The TiZr and Roxolid® were found to have significantly lower elastic modulus values than Ti (p<0.0001, one-way ANOVA). However, there was no statistically significant difference between the TiZr and Roxolid® (p= 0.8712, ANOVA) values. Both TiZr alloys had significantly higher (p<0.05) hardness than Ti with no significant difference between them.
Conclusions: A lower elastic modulus and significantly higher hardness for both TiZr and Roxolid® make them stronger biomaterial suitable for high load bearing implants. The results show that TiZr rod used in this study was sufficiently similar to Roxolid implants with respect to mechanical properties.