How many implants are required to hold a bottom whole denture in?

The number of implants needed depends on several things: Your own bone density and width, your age, and of course check your budget and the protocol or technique your are looking for (removable, not removable, etc), because there are several solutions, if your want something removable the n you can start with 2, or even with snap On dentures (mini implant dentures) or if you want something fixed you can also think about an All-On-4 and All On 6. Think about the options and look for the right treatment for you. I hope this helps. Thank you. 

The answer is 2-5 to secure a lower denture and keep it from slipping around, especially while eating. The more implans are placed, the better. This is because the forces of chewing are spread out over more implants, which the denture more retentive and increases the longevity of each implant. Another factor to consider is the height, width, and density of the jaw bone. The better the quality and quantity of jaw bone available, the stronger the bond of the implant to jaw. I hope that you found this information to be helpful,Dr Champagne

You can use as few as 2 implants to hole in a bottom denture.  The more there are and spaced farther apart, the more stale the bottom denture will be.  You can always start with 2 and add more if you have the available bone.