You could probably use this forever if you really wanted to. It looks like an actual tooth and you can leave it in for days. One kit makes enough for at least 6 months. It's important to watch the instructional videos on Youtube. I had a molar that needed an implant, and this is what I used while waiting for my mold. I could have just saved myself the $ and used this forever, but missing a tooth bothered me being so young.