the hard, white, shiny substance that forms the covering of a tooth
（牙齒的）琺瑯質
Tooth enamel is the hardest substance in your body — even stronger than your bones. It protects the innermost layers of your tooth (dentin and pulp) from damage. Even though enamel is strong, bacteria, plaque and acids in your mouth can damage it. Tooth enamel mostly consists of calcium and phosphorus. These minerals, which make up 95% of your enamel, bond together to form ultra-strong crystallites (small crystals). The rest of your enamel consists of water (4%) and proteins (1%). While you can’t regrow enamel that’s gone, dentists can restore damaged tooth enamel with fluoride treatments. Fluoride remineralizes and strengthens the outer layers of your teeth.
Fluoride, a mineral that occurs naturally in many foods and water, helps prevent tooth decay. Fluoride reverses early decay and remineralizes your tooth enamel. While fluoride can be harmful in large quantities, it’s difficult to reach toxic levels due to the low amount of fluoride in over-the-counter products like toothpastes and mouth rinses.
琺瑯質是人體中最堅硬的物質，甚至比骨頭更硬。它保護牙齒的最內層（象牙質和牙髓）不受損害。即使琺瑯質很堅固，口腔中的細菌、牙菌膜和酸性物質也會對其造成損害。琺瑯質主要由鈣和磷組成。這些礦物質佔琺瑯質的 95%，它們結合在一起形成超強的結晶體（小晶體）。其餘的琺瑯質由水（4%）和蛋白質（1%）組成。雖然您無法再生已經消失的琺瑯質，但是牙醫可以使用氟化物治療來恢復受損的牙齒琺瑯質。氟化物可以重新礦化和強化您牙齒的外層。
氟是一種天然存在於許多食物和水中的礦物質，有助於預防蛀牙。氟化物可以逆轉早期的蛀牙，並使您的牙齒琺瑯質再礦化。雖然大量使用氟化物會對身體有害，但由於牙膏和漱口水等非處方產品中的氟化物含量較低，因此很難達到有毒的水平。
Translated with DeepL and edited
