Impossible to modify koments in the frontend

Hi, even if I have given the possibility to change or to erase comments in the acl configuration to certain users, in the frontend the button for these purposes doesn't appear in my website (http://www.waterwind.it/new/it/report-articoli/articoli-di-waterwind/389-power-jibe-differenti-tecniche-a-confronto.html)

Why? Can you give me some suggestings?

Thanks