<prompt> Which of the following tests is the least useful in endodontic diagnosis of children?PercussionPalpationElectric pulp testCold test  <response>: Electric pulp testL Until apical closure occurs, teeth do not respond normally to electric pulp testing. In addition, a traumatic injury may temporarily alter the conduction capability of nerve endings andor sensory receptors in the pulp. A patient with a vital pulp may not experience any sensation right after trauma. 