In this scene, there is just the text object at 0/0/0 and a point light at 1/1/1. Mostly default settings and the cycles engine are used. (The world surface color is grey, not black, as to be seen in the background)
As you can see, there is are black lines on the edges of the letter. If I reduce the metallic value of the text object, the lines fade a bit, but even with metallic set to 0, they are still visible. Does anyone know what causes this?