When mounting casts for a single fixed indirect restoration like a crown or a bridge, MI should be achieved when?

When mounting casts for a single fixed indirect restoration like a crown or a bridge, MI should be achieved when?

• A. When the patient is wearing a bite guard
• B. When MI can be maintained
• C. Only for fixed indirect restorations
• D. Before any mounting

Answer: (B)

Focus on a stable, repeatable bite. When mounting casts for a single crown or bridge, you set the occlusion to Maximum Intercuspation only if that position can be reliably reproduced and maintained during the lab steps. The restoration will be designed to fit in that reproducible bite, so locking the casts into MI is meaningful only when the patient’s bite can be consistently held there without drift. If MI cannot be maintained, use a different reference position or reassess, because an unstable or inaccurate MI would lead to improper occlusal contacts in the final restoration. Wearing a bite guard by itself doesn’t guarantee a repeatable MI, and MI is relevant to more than just fixed indirect restorations; and MI should not be established “before any mounting” if it cannot be maintained.

Focus on a stable, repeatable bite. When mounting casts for a single crown or bridge, you set the occlusion to Maximum Intercuspation only if that position can be reliably reproduced and maintained during the lab steps. The restoration will be designed to fit in that reproducible bite, so locking the casts into MI is meaningful only when the patient’s bite can be consistently held there without drift. If MI cannot be maintained, use a different reference position or reassess, because an unstable or inaccurate MI would lead to improper occlusal contacts in the final restoration.

Wearing a bite guard by itself doesn’t guarantee a repeatable MI, and MI is relevant to more than just fixed indirect restorations; and MI should not be established “before any mounting” if it cannot be maintained.