The critical characteristic that a base should not have is that it must not be high or left on the walls of preparation. This is essential because a base that is too thick or improperly placed can interfere with the occlusion and lead to discomfort for the patient. It might also affect the seal of the restoration that follows, which can compromise the overall effectiveness of the treatment.
In dental practices, it's important to ensure that the base material is applied evenly and within the boundaries of the prepared cavity. If the base extends too high or stays on the walls, it can create an uneven foundation for subsequent restorative materials, potentially leading to complications such as inadequate bonding or a mismatch in occlusion.
The other characteristics, while they may be beneficial or preferred, do not represent critical factors that directly influence the fundamental effectiveness of the base in a way that impacts patient care or restoration viability. For example, being thin and smooth could enhance adaptation but is not a strict requirement, and consistency in placement is helpful for ease of use but not critical like the height of the material. Color-coding may improve visibility for the clinician but does not affect the mechanical properties or the suitability of the base directly.