Thanks -- I can assure you, with the strong glues there really will be no danger of anything lifting --it`s surprisingly strong! As you will know from reading various posts, everyone`s body can react a bit differently to various glues -- it can take a little time to find one which suits your own needs [length of time you want your bond to last and whether you partake in activities such as gym etc ] You will easily be able to tell if your bond is weakening --- there is no need to panic as it`s a gradual process--------- it doesn`t suddenly fail. If by any chance you do feel part of the perimeter loosening, it won`t lift as such --after all, it`s custom - made, so it`s the shape of your skull and while the glue may weaken, that of itself will not make part of the perimeter lift clear of the skull -- you know what I mean I`m sure. It would not be obvious for that reason. Paul.