Hi @Dr-Sassi, I copied and pasted the elements into a new document and now it's working, thank you very much! Now I've got another problem, the teeth material has lost all its reflection compared to the old document and I don't know why. I checked that all the textures and HDRI were uploaded and the settings on both documents are the same. I just noticed in the RS Asset Manager that these elements are missing and I don't know if that's the reason. Also the problem is on the teeth but the gum is the same as before, so it might be a texture problem. Do you have any ideas?