Provided is a tooth crack observation tip comprising: a tip body inserted in a coupling tube of a light curing device from which a light guide tip has been separated； a crack observation guide tube formed to extend from the tip body by a predetermined length and inserted into the mouth； and a light conversion filter which is coupled to a rear end of the tip body and converts blue light into white light, the light conversion filter being formed by coating a red color and a green color on both surfaces of glass thereof, respectively.
