I do not know why it is so important to me, but it is.
I need Luffy's tooth to come back. I feel like the mising tooth takes away from his "good guy" appearance and makes him look more like a villian (like Blackbeard). Luffy has lost teeth before in a comedic fashion (Skypeia) and Usopp has lost teeth in battle (Alabasta, etc) and they have always come back. I was expecting the tooth to return right away as it has done in the past, but it seems like now that Luffy lost it in a serious fight it may be gone for good or just for a longer time.
I'm still hoping that it will come back when Sanji decides to return but I feel that since so much time has passed without the tooth it might be gone for good. Now when they get back to the crew they are going have to explain why Luffy is missing a tooth and that is going to be added to the list of things Sanji has to apologize for.