Go to a pharmacist.
In Europe this is readily available

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John Chewter
http://www.keyneimage.co.uk
> On a trip and have a root canal tooth whose cap came loose and off after
> 20 years. Is there over-the-counter cement or would silicone adhesive
> sealant available to hold the cap with post in place until I can arrange
> to have a dentist take care of it?