Purposes:To research the clinical features and diagnostic criteria of metastatic malignant neoplasms in gingivae .

目的：探讨牙龈转移性癌的临床特点和诊断标准。

Purposes: To research the clinical features and diagnostic criteria of metastatic malignant neoplasms in gingivae .

目的：探讨牙龈转移性癌的临床特点和诊断标准。

To compare different modes of powered toothbrushing against each other for plaque reduction and the health of the gingivae.

比较各种不同模式的电动牙刷，对于牙菌斑的减少和牙龈的健康的效果。