It is the abradant in the toothpastes that play a part. 4.Artificial saliva with low pH and low fluoride ionic concentration may lead to corrosion of titanium alloy specimens.

• 4.；经含氟牙膏刷洗或浸泡后，浸泡于pH值较低并且含有较低浓度的氟离子（[F-]=258ppm）的人工唾液中，试件就会发生腐蚀。