If you've run out of toothpaste and are tempted to grab your back-up travel tube, you may want to think again. While toothpaste expiration regulations can vary by country, most major brands of toothpaste have a minimum expiration date of eighteen months.
A shelf life is determined only by the effectiveness of the ingredients in the toothpaste, so there's no direct danger to your health in using a recently expired tube at a pinch. But, it does impact the effectiveness of preventing tooth decay and cavities if you use expired toothpaste over the long term. Fluoride in toothpaste can start to break down, decreasing your protection from bacteria-causing decay.
In fact, the ADA has spent many years in partnership with researchers and industry experts to develop a standard for the most effective dentifrice, or toothpastes and powders for cleaning your teeth. Brushing regularly with toothpaste with a low relative abrasivity (or relative dentin abrasivity, RDA) over the course of your lifetime can produce almost no wear to your enamel. Correct toothbrushing with a product that strengthens teeth by remineralising weakened enamel, keeps it strong so that the soft dentin that houses your teeth's nerves is protected. It's important for all the ingredients to be fresh so your toothpaste works best.
On the whole, toothpaste contains five active ingredients, including fluoride, an abrasive, a flavour or sweetening agent, a moisturising agent, and a detergent, which are listed on the outside of the box. Saccharin or sorbitol gives the paste a sweet flavour, and sodium lauryl sulfate is a cleaning agent that works with the humectant to produce a smooth and foamy consistency to help clean your teeth.
Colgate products typically have a two-year expiration date to ensure that the fluoride is at an optimal level of stability, as the ions in the fluoride are at their most effective within two years. After that time, the consistency in colour and taste can change. Most pastes have a similar timeline, although some may have a shorter shelf life. If you reach for a forgotten tube in your medicine cabinet, it's important to check the expiration date before using it.
You should always put the cap back on the toothpaste when you're finished with it, making sure there's no paste around the edges to attract any dirt or dust particles. Likewise, if you store it in the bathroom, it's best to keep your toothpaste in a closed cabinet, and that goes for your toothbrush, too. Though it may be unpleasant to think about, keeping any of your oral products out can expose them to bacteria from your toilet and the area in general. Finally, store your paste in a cooler environment. At hotter temperatures, ingredients can separate and start to liquify, becoming less effective.