传统认为,全冠边缘进入龈下将有利于自洁,防止食物残渣堆积造成对牙龈的不良刺激。但近年有学者通过动物试验却得出了相反结果,认为全冠边缘进入龈下将不仅对牙周组织边缘产生机械性损性,且可作为异物促成牙垢聚集而诱发龈炎。作者通过脑床一例金瓷冠作过程中牙龈变化的观察,亦印证了这一点。 病例报告:张某,女,25岁,因死髓治疗后变色而就诊,给予施行金瓷冠修复,以恢复其正常颜色。常规行牙体制备,唇面 Traditionally, the crown into the subgingival margin will help self-cleaning, prevent the accumulation of food debris caused by the bad gums stimulation. However, in recent years, some scholars have obtained the opposite result through animal experiments. They believe that the entry of the full crown into the subgingival margin not only causes mechanical damage to the edge of the periodontal tissue, but also induces the aggregation of calculus as a foreign body to induce gingivitis. The author also confirmed this by observing the change of gingiva during the process of making a porcelain crown in the brain bed. Case report: Zhang, female, 25 years old, discolored after dead marrow treatment and given gold porcelain crown repair to restore its normal color. Conventional tooth preparation, lip surface