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What is Intracoronal retainer placed in the abutment teeth has the following disadvantage and explain in detail?
Internal or precision attachments
Advantages:

Improved aesthetics, by elimination of a visible retentive component and vertical support.

Disadvantages:

Difficulty in repair and replacing.
Greater cost to the patient.
Inability to use in teeth having short clinical crowns and tissue-supported distal extension denture bases.