粵典 (words.hk)香港詞
黏附喺牙齒表面，黃黃哋乃至啡黑色嘅硬質沉積物；係由#牙菌膜 畀口水入面嘅鈣鹽礦化變硬而形成 (dental calculus; dental tartar)
名詞用例
牙石導致更多牙菌膜積聚，增加患#牙周病 嘅機會。
ngaa4 sek6 dou6 zi3 gang3 do1 ngaa4 kwan2 mok2 zik1 zeoi6, zang1 gaa1 waan6 ngaa4 zau1 beng6 ge3 gei1 wui6.
Dental calculus leads to the accumulation of more dental plaques and the rise of chance of suffering from periodontitis.