The first generations of rotationally symmetrical titanium implants had a relatively smooth, machine-polished surface structure. The clinical disadvantage of this generation of dental implants was that during the early healing phase (the first four weeks after insertion of the implant) there was an increased failure rate in softer bone structures, such as the posterior region of the upper jaw. The roughening of the titanium surface was a big breakthrough: the success rates of these implants increased in comparison with implants with smooth surfaces. Nowadays, it is a scientifically established fact that bone favours surface roughness and bonds better with rough surface structures than with smooth surfaces. The surface of modern implants made of titanium is now machined subtractively in the industrial machining process. Using etching and precisely controlled radiation, the surface is roughened so that the implant is properly prepared for a safe ossification process.
The surface of ceramic implants is also roughened during the manufacturing process. However, it is important to bear in mind that ceramic is an entirely different material with properties which must not be damaged. The latest material science research was able to demonstrate that damage to the surface in the form of micro-cracks resulted from radiation using corundum particles. For this reason, machining the surface of ceramic implants in order to roughen it demands the utmost care and should only be carried out through a safe manufacturing process. The Institut Straumann (Basel, Switzerland) has managed to achieve an implant surface topography that is unique to ceramic implants and appears almost identical to that of titanium implants when looked at under the electron microscope. Scientific evidence confirms that these ceramic implants are just as stable as titanium implants in the ossification process.
