Implants serve as a permanent alternative to removable dentures. A post is screwed or pushed into the jaw bone with a local or general anaesthetic and acts like the root of a natural tooth. The gum is stitched so that it heals over the implant and it takes several months for the bone underneath to grow around it to hold it firm. An extension (replacement tooth) is added at a later stage once this post is secure and the jaw has healed. Implants can also be used to support fixed bridges or dentures.