What are implant-supported dentures (overdentures)?

It is a method of placing 2~4 implants and connecting the denture on top with snap-on attachments. It comes loose less and offers stronger chewing than regular dentures.
When no teeth remain, a lower implant overdenture requires at least 2 implants and an upper overdenture requires at least 4. Fewer implants increase the risk of bone resorption around the implants and eventual implant loss.