If you've ever shopped for toothpaste you know that there are many brands available.  Not only that, but every brand boasts different flavors like mint, cinnamon, spearmint, fruity flavors, etc.  In addition, they often have gels and pastes and claim to target cavity protection, whitening and tartar control to name a few.   The options are endless!  The option you choose depends largely on your preferences for taste and texture.  There is always a debate going on about which is better, but the truth is that they are all effective at cleaning teeth.
However, you hear all the time from dentists that you should brush your teeth with a fluoride toothpaste at least twice a day.   We all know that it is important to brush our teeth to keep them clean and healthy, but why with fluoride?  What is the big deal?
The American Dental Association (ADA) is responsible for approving toothbrushes, toothpaste, floss, etc. for consumer use.  When a product has been approved, they receive an American Dental Association Seal of Acceptance.  If a toothpaste bears the "ADA" seal, you can expect fluoride to be one of the major ingredients because it is an essential combatant against cavities and tooth decay.  They claim that it is more important that a toothpaste contain fluoride than to concern yourself over the consistency and taste of any particular toothpaste.
Weak spots on the teeth are where cavities form and fluoride strengthens these weak areas by encouraging "remineralization".   Fluoride is documented to be safe and very effective.  In fact, only small amounts of fluoride have been shown to achieve maximum benefits.  When used in small amounts on a regular basis it helps to prevent tooth decay. 
Fluoride is found naturally in water which has been shown to be the best source of fluoride.  Drinking fluoride water has shown to decrease the decay rate of teeth by over 50 percent.  Fluoride is also found in many different foods as well as in dental products such as toothpaste, mouth rinses, gels, varnish and supplements.  Fluoride can be very effective when combined with a healthy diet and good oral hygiene.
Amounts of fluoride vary in water sources, so some people receive more or less than others.   Depending on this, a person's age and their risk of developing tooth decay, a dentist may recommend a patient take a fluoride supplement.  However, something to be aware of is that it is possible to overdose on fluoride.  Young children should not swallow toothpaste, especially if it contains fluoride because doing so can lead to them consuming up to four times the recommended amount of fluoride.  This can lead to the development of spots on their developing permanent teeth.  Proper toothpaste amount must be supervised and other forms of fluoride supplementations must be carefully monitored in order to prevent a potential overdose.
Topical fluoride is another way to get fluoride to strengthen your teeth.  It comes in the form of a gel or a foam and is applied to your teeth in the dentist's office after a cleaning.  Fluoride varnish is one of the newer forms of topical fluoride and has been documented to be safe and effective in fighting dental decay. 
In summary, fluoride has been proven to be an effective element in the prevention of cavities by strengthening weak spots on the teeth.  The people who benefit the most from fluoride are those at highest risk for dental decay. Risk factors include a history of decay, high sucrose carbohydrate diet, orthodontic appliances and certain medical conditions such as dry mouth.  However, regular use of fluoride can be a benefit for everyone.