Which instrument has two angles in the shank to assist in cavity preparation?

The instrument designed with two angles in the shank to assist in cavity preparation is known as the binangle chisel. This unique design allows dental practitioners to access hard-to-reach areas within the cavity, especially in the posterior teeth. The binangle shape offers greater maneuverability and control, making it easier to remove decayed tooth structure and refine the cavity preparation.

The angling of the shank optimizes the angle at which force is applied, which can be particularly useful in aligning the chisel with the surface of the tooth that is being prepared, ensuring that the dentist can work efficiently and accurately. The specific design of the binangle chisel enables it to be effective for various tasks during cavity preparation, thus playing an essential role in restorative dentistry.

Other tools like the angled former and spoon excavator have different purposes or configurations, which do not provide the same benefits in cavity preparation as the binangle chisel. For instance, a spoon excavator is primarily used for removing carious dentin and has a different design focused on that task rather than multi-angle access. Meanwhile, an anesthetic syringe is unrelated to cavity preparation at all, as its function is to deliver anesthetic agents.