Praise be to Allaah.
Please note that tattoos on the body are haraam, because it was reported that the Prophet (peace and blessings of Allaah be upon him) cursed the one who makes hair extensions and the one who asks for that to be done, and the one who does tattoos and the one who asks for them to be done. If a Muslim does that when he is unaware of the fact that it is haraam, or that is done to him when he is a child, then he has to remove it when he comes to know that it is haraam. But if removing it is too difficult or will cause him harm, then it is sufficient for him to repent and seek forgiveness, and it will not matter if he leaves the mark on his body. With regard to having a gold tooth fitted when it is not needed, this is not permissible, because gold is haraam for men, unless there it is necessary for some valid reason. I understood from your question that you did that for the purpose of beautification, so you have to remove it. You can have it replaced with something else that is made of permissible material, other than gold. May Allaah help us all to do that which pleases Him. Wa’l-salaamu ‘alaykum wa rahmat-Allaah wa barakaatuhu.