Even in the tightest pocket FAK it pays to insert a birthday candle or tiny stub of a candle.

The wax can be stuffed into the hole left by a missing filling or wrapped around the tooth stub of a broken tooth or where a crown has been lost. To be used this way you have to be careful about which candle you select. The modern plastic candles with a rubbery or stiff consistency don't work well. Beeswax based candles and others that will soften in the mouth sufficiently that they can be worked like putty with the fingers is what you want.

They also make a good fire starter, fuel for light and heat, solid-form lubricant and sealer. Warmed and thumbed into a leak in a rain fly or raincoat it can help keep you dry and eliminate the annoyance.

Its roll as stopgap in field expedient dentistry is another plus.