To facilitate plaque removal, what must an interim fixed restoration have?

An interim fixed restoration must have a good marginal fit to facilitate effective plaque removal. A well-fitting margin minimizes gaps between the restoration and the tooth structure, which can harbor plaque and bacteria. When the contour and margins of the restoration are properly designed, it allows for easier cleaning with toothbrushes and aids in the maintenance of periodontal health. A good marginal fit also prevents food impaction and minimizes the risk of decay developing at the junction between the natural tooth and the restoration.

In contrast, options that suggest poor contour or rough surfaces would likely contribute to the accumulation of plaque rather than its removal. An excessive marginal fit could indicate a poorly designed restoration, leading to similar issues of plaque retention. Therefore, the correct choice emphasizes the importance of achieving a snug and proper fit for effective oral hygiene and overall health.