The power of ultrasonic vibrations has been harnessed in the field of dentistry—evolving in its use and purpose—for just over 60 years. The first section of this review describes the evolution and various applications of ultrasound in dentistry, and examines in detail the ultrasonic tools that have been developed for endodontic purposes. The second section of this review describes the use of ultrasonics during specific endodontic procedures, from access to obturation, incorporating as much as possible the most recent and relevant research available to date.