It's all about the frequency, not the amount of sugar!
Sugar does cause cavities, but we aren't saying that you have to avoid it all together.
Let's say you tend to drink a whole gallon of orange juice in one day.
Follow these tips to help reduce your risk of cavities:
Drink the orange juice in one sitting and during meals rather than one sip every 20 minutes.
Drink from a straw. Straws prevents the sugary juice from touching all the surfaces of your teeth.
Rinse with water afterward. Water helps wash away some of the sugar and also neutralizes the acid.
What increases your cavity risk are the habits when consuming the sugar-rich and acidic orange juice.
Cavities happen when the natural bacteria on teeth digest the sugar we eat and produce acid that decays teeth. The bacteria can only digest a certain amount of sugar at one time, so even though you feed the bacteria a whole gallon of orange juice at one time, the bacteria gets full and only digests a small percentage of that orange juice and so it only produces the acid once. On the other hand, if you feed the bacteria a sip of orange juice constantly throughout the day, this allows the bacteria to have time to digest the sugar, produce acid, and get hungry again for more sugar when the next sip comes. Bacteria can produce acid every 20 minutes.