The tip of the composite curing light should be held at an angle of _____ degrees to the tooth:

The tip of the composite curing light should be held at an angle of 90 degrees to the tooth to ensure optimal curing of the composite material. This perpendicular position allows the light to directly reach the composite surface, maximizing the intensity and distribution of light, which is essential for effective polymerization.

When the light is held at this angle, it minimizes the loss of light energy due to scattering or reflection, ensuring that the composite receives the full benefit of the light output. Holding the light at 90 degrees also helps in achieving a uniform cure across the surface of the material, which is critical for the longevity and strength of the restoration. This is particularly important in dental procedures, where a well-cured composite can lead to better aesthetic outcomes and increased resistance to wear over time.