Which of the following conditions could contraindicate the placement of a posterior composite restoration?

The placement of a posterior composite restoration can indeed be contraindicated if the composite will be subject to high occlusal tooth contacts. This is because composites, while providing excellent aesthetics and bonding capabilities, may not withstand the forces that result from heavy occlusal contact. When placed in areas where they are subjected to significant biting pressure, such as posterior teeth that experience the most force during chewing, these restorations may wear down more quickly or even fracture.

In contrast, options that address esthetics or cavity surface conditions do not present the same level of concern regarding the strength and durability of the restoration. While esthetics can influence a patient's decision, it does not inherently affect the restoration's longevity or its functional effectiveness. Similarly, if all cavity surfaces are on enamel, or the remaining enamel will have occlusal stops, these scenarios do not create a significant risk for the restoration under functional conditions. Thus, the mechanical properties and stress distribution associated with high occlusal tooth contacts are pivotal when evaluating the suitability of a composite restoration in posterior teeth.