"putting an implant to sleep" means removing the stump on the implant, but leaving the implant itself in place and allowing the gum
tissue to grow over it, thus "burying it" under the gum
. again, the implant stays in the bone, it's just not going to be used anymore. in my humble opinion, if the implants are sound and properly aligned, and they are clean and maitaianable, you should not have to "bury" any of them.