Final answer:
The margin of a temporary crown should extend slightly to the gingival margin or just below it to ensure a good seal and prevent leakage. It should be smooth and well-polished to prevent plaque build-up and irritation. Contouring the margin properly is important for the health of the gums and surrounding structures.
Step-by-step explanation:
The margin of a temporary crown should extend slightly to the gingival margin or just below it. This is important to ensure that the crown provides a good seal and prevents any leakage or sensitivity. The margin should be smooth and well-polished to prevent plaque build-up and irritation to the surrounding tissues.
For example, if a temporary crown is being placed on a tooth with decay or a filling that extends below the gingival margin, the margin of the temporary crown should extend slightly below the decay or filling to ensure a proper seal.
Additionally, it is important for the margin of the temporary crown to be properly contoured to maintain the health of the gums and surrounding structures.