Objective: Placing stud type attachments on the natural root and extracoronal attachments on the ceramic crown in order to get retention for overdentures.

• 目的：在牙根上放置本院研制的球帽型附着体，烤瓷冠上放置冠外附着体，利用上述混合固位体增强覆盖义齿的固位力。