单项选择题
A.0.5mm B.0.5~1mm C.1~2mm D.3~4mm E.5~7mm
A.观察,若有临床症状,取出后重新充填 B.立即取出重新充填 C.观察,若有临床症状,行根尖外科手术 D.立即行根尖外科手术 E.拔除
A.18mm B.19mm C.20mm D.21mm E.22mm