Figure 9.

Polished titanium implants (a) were for a long time considered the best choice for a hard tissue implant because of their superior elastic properties. Then it was discovered that adherence and internal proliferation of cells would require introduction of topographic irregularities (b) and macroporosity (c), respectively. Their non-biodegradability and the tendency to weaken the surrounding bone and cause its resorption have contributed to their substitution with softer, less biomechanically superior materials (d).