Tori Simmons and Ben Chumley1-10-18MillerPhysical science1A Teeth whitening depends on the teeth being stained. So you have to realize how teeth can be stained in the first place to be able to whiten your teeth back to normal. According to 1800dentist.com, tooth stains are caused by the habits of people. For instance, not flossing or brushing teeth, drinking caffeine, smoking or chewing tobacco, etc. There are two types of teeth staining. Extrinsic, which stains that occur on the outside because of the word meaning exterior. The next type is intrinsic, those that occur within the tooth itself more like the natural color. Determining the type of staining you have is the first step to the brighter smile you want. Dentalplans.com explains, “Extrinsic stains happen because of the structure of tooth enamel. While your teeth may feel smooth, the enamel actually contains microscopic depressions…Even substances used for oral hygiene, like the anti-bacterial ingredient chlorhexidine, can stain teeth. Fluoride, a naturally occurring chemical that strengthens enamel against tooth decay, may cause a brownish discoloration if consumed in quantities above recommended levels during tooth development.” This statement shows how the chemistry of science stains the external layer of your enamel, the extrinsic part. Dentalplans continues to say, “Intrinsic staining, on the other hand, stems from causes within the tooth. (Dental plans continues) Certain materials used for dental fillings or traumatic tooth injuries can alter tooth color significantly. With saying that, the person’s teeth does not look discolored until it’s up against something white. This piece of evidence talks about Intrinsic teeth and how they are affected by chemicals they use to whiten them from the basic color they are. A website called mayoclinic.org tells us that whitening toothpaste can appear to whiten teeth but it is known to change the natural color of your teeth and weaken your enamel. Products like these are not always good for your teeth regardless if it whitens them or not, it weakens the enamel and makes your teeth extremely sensitive. Users need to gain basic knowledge about their teeth and realize how much their everyday habits really affect them, good or bad.