Which instrument is commonly used to smooth interproximal surfaces?

Finishing strips are specifically designed for smoothing interproximal surfaces, which are the areas between adjacent teeth. These strips are typically made of a flexible material and are coated with abrasive particles that allow for effective shaping and smoothing of restoration margins or tooth surfaces, particularly in tight spaces where other instruments may not be efficient.

In restorative dentistry, achieving a smooth finish is essential not only for aesthetic purposes but also to prevent plaque accumulation and ensure proper contact between teeth. Finishing strips can be easily maneuvered to adapt to the contours of the teeth, making them ideal for achieving the desired surface finish in interproximal areas.

The other options do not serve this purpose: articulating paper is used to check occlusion and contact points, curing lights are utilized for hardening dental materials, and shade guides are used for selecting the color of materials for restorative procedures. Thus, finishing strips are the correct choice for smoothing interproximal surfaces.