With three different retainer designs, the retainer on the second premolar and the first molar exerted the smallest stress on the abutment and its periodontal tissue, while the retainer on the first premolar and the first molar had the largest stress.

• 在3种不同的固位体设计方式中，固位体放置在第二前磨牙与第一磨牙之间时，基牙及牙周组织受力最小；固位体放置在第一前磨牙与第一磨牙上，基牙与牙周组织受力最大。