1. Acids, Bases, Universal Indicator, the pH Scale and the Impact on Tooth Decay
Mariam Al Thani 7A

2. pH Scale
The pH scale measures if something is an acid or a base on a scale of 1 to 14.
Acids have a pH less than 7
Bases have a pH greater than 7
A pH of 7 is neutral

3. pH and saliva pH of saliva is between 6 and 7
If the pH is 6, then it is 10 times more acidic than a pH of 7
pH can be tested with universal indicator
Color change with pH change

4. Acids & Bases Acids taste sour Bases taste bitter Bases feel slimy
Acids and bases react with each other

5. Acids and Tooth Decay
Cavities are formed when bacteria in plaque produce acids
The bacteria that causes tooth decay feed on sugars
It is important to brush your teeth after eating

6. Toothpaste and Tooth Decay
Fluoride in toothpaste and water helps to prevent tooth decay
Fluoride attaches to teeth and makes teeth reform calcium lost to acids from bacteria