Are friends electric?: a review of the electric handpiece in clinical dental practice

Since the foot-powered dental drill was invented by James Beall Morrison in 1871, operative dentistry has relied heavily on rotary instrumentation. The air rotor was first introduced in 1957 and, for many clinicians, remains the most popular technique for high-speed tooth preparation1^,2 (Figure 1).

In recent years, the profession has moved away from providing restorations that require conventional tooth preparations and, instead, moved towards the use of minimally invasive restorative techniques. The success of these techniques demands extremely accurate and precise tooth preparations.^3–7 Ibbetson8 has suggested that a precise 0.5 mm axial groove preparation is important for the provision of predictable adhesive bridgework. Magne and Belser9 have demonstrated that porcelain restorations can be successfully used to restore damaged teeth in the presence of a strong porcelain to enamel bond. It should be appreciated, however, that enamel can be extremely thin at the amelocemental junction (acj) and unintentional overpreparation in this area is a frequent problem, leaving little or no enamel on which to bond.