Artificial discs have been around long enough to go through several changes. Research is ongoing. As a result sizes, shapes, and materials keep changing for the better. As you say, the materials are metal, plastic, or ceramic.
Each disc is made up of two or three moveable parts. This could be metal on metal, metal and ceramic parts, or metal/plastic design. The all-metal implants can rub and cause tiny flecks of metal debris. Problems can develop as a result.
The ceramic parts can shatter or break without warning. Plastic wears out sooner than metal or ceramic. The good news is that discs last much longer than hip or knee replacements. It has freer motion in the spine with less stress.
Ask your doctor for his or her opinion as well. Many doctors tend to use one material more than another and have some experience with long-term results.