Cracked tooth is a syndrome familiar to most dental professionals. The development of cracks is a common complication in restored posterior tooth. Usually, the crack originates in the deepest part of the of the occlusal box and runs diagonally out under a cusp. The signs and symptoms of a cracked tooth include sensitivity to temperature changes, to sugar, or tenderness on biting.Generally, a cracked tooth cannot be detected clinicallyor radiographically. Therefore, it can be difficult to diagnose or to localize the tooth or cusp. Dentistshave used various implements to locating a cracked cusp. These, among other things, include cotton rolls, wood sticks and metal instruments. All of these implements have limitations.Fracfinder is an indispensable instrument for the practice of modern dentistry. It is an instrument that simplifies locating cracks in tooth. Locating cracks with Fracfinder is quick and precise. To locate the crack, place the small indentation of the Fracfinder on suspected cusp. Ask the patient to apply pressure while gently biting on the suspected cusp(s). Fracfinder provides force when the patient bites down on the instrument. Cracked cusp is then located easily, rapidly and precisely.