In which situation would a liner and/or base not be indicated for a class II restoration?

In a Class II restoration, the decision to use a liner or base largely depends on the condition of the cavity preparation and the proximity to the pulp. When the pulpal floor is prepared at an ideal depth, it indicates that there is adequate tooth structure remaining between the cavity and the pulp. In such circumstances, the risk of pulp exposure or irritation is minimized, and the use of a liner or base is not necessary.

Liners and bases are typically utilized when there is a concern about potential pulp irritation, either due to the proximity of the restoration to the pulp or when thermal insulation is needed. In the case of a concave axial wall from extensive decay, a near pulp exposure, or a subgingival gingival floor, the risks associated with these conditions would warrant the use of liners or bases to protect the pulp and provide a sealing effect. Therefore, the ideal depth of the pulpal floor suggests a stable environment where additional protective measures are not required, confirming that no liner or base is necessary in this situation.