When all of the teeth are missing in an arch,  we may recommend complete dentures.  With today's technology, we are able to stablize dentures with implants or even place fixed dentures that cannot be taken in and out to give a more natural appearance.   When implants are used the  bone is preserved, helping it stay healthy and in tact.  With implant suppported dentures,  there is no worry of the dentures coming out while chewing or talking as with conventional dentures.