Objective: To observe the effectiveness of using stainless steel crown (SSC) or composite inlay/onlay (CI/O) in early treatment of the badly broken-down first Permanent molar for children.

• 摘要目的：观察不锈钢预成冠及复合树脂嵌体早期修复儿童后牙大面积缺损的临床效果。