覆盖义齿是覆盖在牙根或牙齿上的义齿。它与普通义齿相比具有生理上优势,是修复科医师和患者喜爱的一种修复方法。但是覆盖义齿下方所覆盖的牙根或牙齿,特别是牙根的根面易龋坏,使保留牙根不能长期保留于牙槽骨内。为此,临床医师采用不同方法来预防根面龋,归纳起来大致有下列几种:(1)根面涂布药物,如涂布氟化钠等。(2)金属顶盖覆盖 Overdenture is a denture that covers the tooth root or tooth. It has a physiological advantage over normal dentures and is a favorite repair method for physicians and patients. But covered under the denture covered roots or teeth, especially the roots of the root carious carious, so that the root can not be retained for long-term retention in the alveolar bone. To this end, clinicians use different methods to prevent root caries, summed up the following general: (1) the root surface coating of drugs, such as coating sodium fluoride. (2) metal roof cover