In full gold crown, to prevent future gingival recession.. Make the tooth form good at gingival one third

In full gold crown, to prevent future gingival recession: 

• a- Make the tooth form good at gingival one third.***
• b- Make the tooth form good at gingival one fifth.
• c- Make the tooth form good at gingival one half.

The correct answer is (a) Make the tooth form good at gingival one third.

This is because placing the gold crown margin at the gingival one-third provides several benefits for preventing gingival recession:

- Reduces gingival irritation:

By placing the crown margin below the gingival margin, there is less direct contact between the crown and the gingiva, reducing the risk of irritation and inflammation.

- Maintains a healthy gingival seal:

The gingival sulcus, the space between the tooth and the gingiva, plays a crucial role in maintaining a healthy seal around the tooth. Placing the crown margin below the gingival sulcus allows the gingiva to properly attach to the tooth, preventing bacteria and debris from accumulating under the crown and causing inflammation.

- Preserves periodontal attachment:

The periodontal attachment is the connective tissue that anchors the tooth to the alveolar bone. By placing the crown margin at the gingival one-third, more of the periodontal attachment is preserved, providing better support for the tooth and reducing the risk of tooth loss.

Option (b) would place the crown margin too close to the gingival margin, increasing the risk of irritation and inflammation. Option (c) would place the crown margin too far away from the gingival margin, leaving more of the tooth exposed and potentially leading to gingival recession.

Therefore, placing the gold crown margin at the gingival one-third is the optimal position to prevent future gingival recession.