The Orange, Lemon, Lime and Grapefruit Oils will dissolve hardened plaque much like such fruit acids dissolve dead skin when applied as a cream.

• 甜橙、柠檬、酸橙和葡萄柚油将溶解硬化的牙石，就象果酸作为皮肤霜使用时溶解死皮一样。