Fig. 1

Angled configuration of the designed handpiece in this study. When the angle between the head and body portion of the hand piece is “θ,” the angle between a line perpendicular to the sensor and a line extended from the axis of the drill is also “θ” (a). The body to head transition matrix formula (b) translates the three axial angles of the hand piece body (x’, y’, z’) into those of the dental drill as x, y, and z, respectively (c). Due to this formula, we do not have to create a different electric circuit board for every different type of handpiece. Since it is the dental drill that reduces the tooth structure and not the handpiece, this process improves the clinical efficacy of the device