I don't think that he even stopped using it ..
It's just that in the manga , the scan translators don't add it in the text .
say for example when Naruto yelled at Madara in the latest chapter saying " You were once dead , don't mess with the living now !! " , it would be weird and anti-climactic if they made it like : " You were once dead , don't mess with the living now'ttebayo !! " ..
see what I mean ?