What is the recommended incisal reduction for a full crown preparation?

The recommended incisal reduction for a full crown preparation is between 1.3 to 1.5 mm. This level of reduction is essential to provide adequate space for the thickness of the crown material, which is crucial for both aesthetic and functional outcomes. Sufficient incisal reduction ensures that the final restoration has the necessary strength, translucency, and resistance to fracture while also allowing the appropriate contours and anatomy to be achieved.

In addition to creating space for the crown material, proper incisal reduction helps in achieving the desired occlusal clearance, ensuring that the new restoration does not interfere with the patient's bite. The selected range of 1.3 to 1.5 mm strikes a balance between preserving tooth structure and providing optimal conditions for the crown to perform effectively.

The other options, while considering different thicknesses, do not meet the minimum recommended reduction for effective crown preparation. Reductions that are too minimal may not provide sufficient space, risking compromised esthetics and durability of the crown.