Just reading this thread reminded me of something that might be useful to folks.
A few years back, my wife broke a crown when we were away camping. Miles from anywhere, Saturday night on a bank holiday weekend. Drove to the nearest town the following morning only to be directed to another town a few miles further on. Found a phone number for the dentist but still had to wait until Tuesday then pay an absolute fortune to get it fixed.
I now keep a pack of temp tooth filler in my big first aid kit as well as another one in the car kit. Give your teeth/mouth a quick clean, cut of a little bit of the filler and roll it in a ball before pressing it into the gap. Sets really quickly and kills the pain pretty rapid too. After an hour or so you can eat/drink/be merry.
This is the type I use...
http://www.amazon.co.uk/gp/product/B0017JPRV0/ref=oh_o03_s00_i00_details
This type is already mixed and ready to be used. Avoid the types which have a sachet of powder and some solution as they're a pain to use and to get the consistency right, especially if you're in pain at the time.
They will last for a few days if needs be and are great for short term relief till you can get to a dentist.
No connection, no affiliations, blah blah...