One of the main difficulties some people have with implants is that they are metal. I am not sure if titanium is a problem in bone unless you are allergic to it. We recommend being tested if such implants are desired or proposed. We also do not like dissimilar metals in the body as they set up galvanic cells and create electricity that is undesirable. It can interfere with normal electrical control circuits used to regulate bodily functions.
We now do provide zirconia ceramic implants. Straumann, a very big and reputable implant supplier, is a Swiss company with a very strong research base. They have released a very elegant and well engineered zirconia implant system. This was released in Germany in late 2014. We placed the first of these implants in Australia in December 2014. We are now regularly placing these restorations, so far with no particular or unusual problems.
Research suggests that they will be as successful as the conventional titanium implant that have been used for decades.
Staumann have a link http://www.straumann.co.uk/en/dental-professionals/straumann-products-and-solutions/implant-solutions/ceramic-implants.html that will give more information.