Hello You should visit a dentist and get the problem sorted as soon as possible. There are various options but the most natural one is via braces( Invisalign ) they are invisible aligners and very comfortable. The other less invasive option is via composite restoration build up. You can also get crowns to close the gap in which tooth preparation is done and the size of the tooth is decreased. But all this depends on the distance of the gap and your occlusion/ bite. Please visit for consultation and get it treated soon.