What is the primary use of spoon excavators?

Spoon excavators are primarily used to remove carious dentin from a tooth. These hand instruments feature a scooping or spoon-shaped end, which is specifically designed to reach into the cavity and effectively scoop out decayed tissue. This process is critical in preparing the tooth for further restorative procedures, such as filling, by ensuring that all infected and softened dentin is eliminated.

In terms of cavity preparation, the removal of carious dentin helps to prevent further decay by eliminating the source of infection, thereby promoting a healthier environment for restoration. This step is essential in dental treatment, as leaving any caries behind could compromise the integrity and longevity of the restoration.

The other options, while related to dental procedures, do not accurately reflect the primary function of a spoon excavator. For instance, beveling walls and cleaning cavities involve different tools and techniques, and injecting local anesthetics typically utilizes syringes and needles rather than hand instruments like excavators.