Anyway, they no longer fill your mouth up with alginate – the gooey purple impression taking stuff – send the impression away, and then get you your new crown a couple of weeks later; instead they have a scanner linked to a miniature porcelain milling machine. Or they do at my dentist. Amazing. (Of course, they don’t have NHS treatment anymore at my dentist, but that another story. These few cubic millimetres of procelain are going to cost a fortune.)

This amazing tooth-milling machine is just like the key duplicating machines that were apparently going to appear in DIY sheds and elsewhere. Locksmiths (with vast budgets – not me) might have these as well. You put your key in, a three-dimensional scan is made, and your duplicate key is milled from solid brass.

Instead of having to have key blanks to cover all the different profiles and sizes, a solid piece of metal is milled giving not just the bitting (the jaggy bit) but the profile (the wavy, er, profile) as well.

The worry was that people would be able to duplicate keys that were supposed to be restricted sections. These are where your lock installer has assured you that only you can duplicate your key since only you have access to the only locksmith who has the blanks.

No-one I know, however, has actually seen such a scanner/miller in their local DIY shed.