Method 120 operation patients with cholelithiasis were randomly selected, their saliva PH value and dental fungus speckle index before operation were checked, then sugarless chaw gum was given after operation, and the same index were rechecked.

• 方法随机选择 12 0例胆石症择期手术患者 ,术前检测唾液pH值和牙菌斑指数 ,术后给患者嚼无糖口香胶 ,分别检测术前同样内容。