Unfortunately, many people can experience the pain of sensitive teeth after whitening. When your teeth are sensitive, they can have enhanced responses to hot and cold drinks, brushing your teeth or sweet foods – in the form of short, sharp pain. This sensation frequently occurs during the early stages of bleaching treatment when the hydrogen peroxide penetrates your tooth enamel, exposing the nerves in the dentine beneath it.
Products like whitening toothpaste may cause less sensitivity because they only treat stains on the surface of your teeth and are less likely to penetrate through your tooth enamel. However, different patients can experience different results using the same product depending on their teeth. Generally, gels used in bleaching trays and products purchased from your dentist have a greater potential for causing sensitive teeth after whitening as they tend to have a higher concentration of hydrogen peroxide.
You may also experience gum irritation with the use of peroxide-based bleaching agents, though sometimes gum tissue irritation comes from ill-fitting trays used to hold the bleaching agent.