you have not mentioned how the tooth has come out. If it has come out due to trauma or accident then replantation is possible but if it has come out as it has become loose due to infection or gm problem then it is better to go for the replacement. You can visit the dentist to get the replantation done. If you want to know more about the replantation then you can visit the following link on our website.......http://www.identalhub.com/articlecategory-tooth-replantation-61.aspx