If the root of a tooth measures 16 mm in length, how long should the post be?

If the root of a tooth measures 16 mm in length, how long should the post be?

• A. 9 mm
• B. 11 mm
• C. 13 mm
• D. 15 mm

Answer: (B)

In determining the appropriate length of a post for a tooth with a root measuring 16 mm, it’s crucial to consider that the post should ideally engage the root canal without extending excessively beyond it. The purpose of the post is to provide support for the restoration while allowing for sufficient remaining dentin to ensure the structural integrity of the tooth. A commonly accepted guideline is that the length of the post should be approximately two-thirds of the root length. In this case, two-thirds of 16 mm is roughly 10.7 mm. Thus, a post length around 11 mm aligns with this recommendation, offering optimal retention while preserving enough root structure for strength and support. Selecting an 11 mm post allows the dentist to achieve a balance between retention of the restoration and maintaining the tooth’s health and integrity. This length also mitigates the risks associated with over-instrumentation and potential complications from extending the post too far into the apical area.

In determining the appropriate length of a post for a tooth with a root measuring 16 mm, it’s crucial to consider that the post should ideally engage the root canal without extending excessively beyond it. The purpose of the post is to provide support for the restoration while allowing for sufficient remaining dentin to ensure the structural integrity of the tooth.

A commonly accepted guideline is that the length of the post should be approximately two-thirds of the root length. In this case, two-thirds of 16 mm is roughly 10.7 mm. Thus, a post length around 11 mm aligns with this recommendation, offering optimal retention while preserving enough root structure for strength and support.

Selecting an 11 mm post allows the dentist to achieve a balance between retention of the restoration and maintaining the tooth’s health and integrity. This length also mitigates the risks associated with over-instrumentation and potential complications from extending the post too far into the apical area.