對於兒童預防蛀牙，哪項屬於初級預防？
Which of the following is a primary prevention measure for dental caries in children?
- APerforming a root canal執行根管治療
- BExtracting a decayed tooth拔除蛀牙
- CFilling a cavity填充蛀洞
- DApplying dental sealants✓ 正解塗佈窩溝封填劑
初級預防（Primary prevention）的核心目的在於疾病發生前採取行動，以消除風險因子或增強機體抵抗力。牙科窩溝封填（Dental sealants）是在幼兒恆牙咬合面塗上一層保護膜，物理性阻斷細菌與食物殘渣堆積，從根本上阻止齲齒發生。相比之下，其他選項皆針對已發生的病變進行修復或移除，屬於三級預防（Tertiary prevention），旨在減緩疾病惡化或恢復功能，而非預防疾病發生。
The purpose of primary prevention is to act before disease develops, eliminating risk factors or strengthening host resistance. Dental sealants involve applying a protective coating to the occlusal surfaces of children's permanent teeth, providing a physical barrier against bacteria and food debris accumulation and preventing caries at its source. In contrast, the other options all involve repair or removal of already established disease and belong to tertiary prevention, aimed at slowing disease progression or restoring function rather than preventing onset.