Often in situations such as endodontic surgery utilizing high powered microscopes are used by both the dentist and assistant for improved visibility (Figure 34).
In this case, a third set of hands becomes valuable in retraction and preparation of materials. While the first clinical assistant is attentive to the treatment on a specific site the second clinical assistant must anticipate the needs of both the primary assistant as well as the operator. All of the previous instrument transfer techniques are still followed during basic instrument transfer. However, but the second assistant may need to be on the side of the operator to avoid congestion and to gain improved visual access (Figure 35).