Inadequate contacts of interim restorations allow for which types of movement?

Inadequate contacts of interim restorations can indeed allow for both supraeruption and horizontal movement.

Supraeruption refers to the movement of a tooth in an occlusal direction, often occurring when opposing teeth do not make sufficient contact. When an interim restoration lacks proper interproximal contacts, the adjacent teeth may experience changes in their occlusion, leading to supraeruption. This can lead to uneven wear and shifts in the dental arch over time.

Horizontal movement, which can occur when the contacts are inadequate, involves lateral shifting of the dental structure. If the interim restoration does not provide enough resistance or stability between adjacent teeth, they can move horizontally, affecting alignment and bite.

Consequently, because inadequate contacts can contribute to both types of movements in the surrounding dentition, the correct answer encompasses the possibility of both phenomena happening when the restoration does not achieve proper interproximal contact.