It is that yellow or white chalky like stuff found in between the teeth called dental calculus. It’s a build up of hardened plaque brought about by an improper maintenance of oral hygiene. If you don’t clean your teeth properly, the plaque begins to build up and will eventually harden over time if you let it build up. Prevention they say is better than cure and, cheaper too because once the dental calculus hardens only a dentist or dental professional can remove it. The best way to prevent this is by observing the three rules of oral hygiene
Brush regularly, twice a day using a toothbrush with soft bristles and toothpaste that contains fluoride as it helps repair enamel damage. Give your teeth a good scrub for 2 minutes, brush your teeth and on your rear molars.
Flossing daily keeps your teeth healthy, it reaches the place your brush cannot and helps keep the plaque from growing in-between your teeth. Flossing also decreases your chances of having bad breath, you see when food particles are trapped between the teeth, they begin to break down and rot, and in the process gives off foul odours, but when you floss you’re able to reach these trapped food particles and get them off before they rot.
You can rinse with a mouthwash or a simple salt water rinse ( to make a salt water rinse add ½ teaspoon of salt to a cup of warm water)
I wouldn’t advise rinsing daily with the salt water rinse, 2-4 times a week is enough as too much sodium from the salt water can have negative effects on your tooth enamel. Rinsing your mouth after every meal reduces the bacteria and stops cavities from forming. It also freshens the breath.
And also, watch your diet as the bacteria in your mouth survives on food that contains sugar and starch. Drink plenty water after meals and avoid smoking.