The most frequent cause of failure of a cast crown restoration is:
- a. Failure to extend the crown preparation adequately into the gingival sulcus.
- b. Lack of attention in carving occlusal anatomy of the tooth.
- c. Lack of attention to tooth shape, position, and contacts ***.
- d. Lack of prominent cusps, deep sulcus, and marginal ridges.
You're right! The most frequent cause of failure of a cast crown restoration is a. Failure to extend the crown preparation adequately into the gingival sulcus.
Here's why:
Inadequate gingival margin extension:
This can lead to:
- Microleakage: Saliva and bacteria can infiltrate the gap between the crown and tooth, causing caries, inflammation, and gum recession.
- Poor marginal seal: The crown may not properly adhere to the tooth, compromising its stability and increasing the risk of failure.
While all other options can also contribute to failure:
- Lack of attention in carving occlusal anatomy: can affect chewing function and lead to occlusal imbalances.
- Lack of attention to tooth shape, position, and contacts: can affect the aesthetics and function of the crown, but not necessarily its survival.
- Lack of prominent cusps, deep sulcus, and marginal ridges: might affect aesthetic outcomes but not necessarily lead to failure.
Therefore, failure to properly extend the crown preparation into the gingival sulcus is the most critical factor in preventing cast crown failures.
Additional factors to consider:
- Proper tooth preparation is essential for a successful crown restoration, and neglecting any aspect of it can increase the risk of failure.
- Material selection, fabrication technique, and proper cementation also play a role in the long-term success of a cast crown.
