As above these screws, sticky worms and any other repair made externally should only be considered as a temporary get you home fix. Here in the UK there is a British Standard for puncture repairs (BSAU159) that specifies the tyre has to be removed from the rim and inspected for any secondary damage, it also specifies the repair as an internally fitted vulcanised mushroom patch.
That said I've run car tyres over 35,000 miles and motorcycle tyres over 8,000 miles on sticky worm puncture repairs, however, you roll at your own risk any puncture repair is only ever going to be as good as it is applied.