We believe that anything we use in the mouth should help us move in the direction toward optimal oral health. So, if some chemical causes a temporary inflammatory response inside the deepest layer of our teeth, this causes real concern for us. Is it a huge deal? Maybe not. After all, within a week from bleaching, in almost all participants, hyper-sensitivity was gone. (However, in all fairness, we should also mention that for some people the increased tooth sensitivity is permanent micro motor.) But does the research clearly show that bleaching agents cause a stress to the immune system? Yes. It just seems to us that our immune systems can only take so many ‘whacks’ before they begin to show signs of wear and tear. Yeah, there’s a place to argue that we need some challenge/stress to get stronger and we agree with that. But is the risk of causing inflammation in the deepest layer of tissue of our teeth really worth it? That’s your call… Gum tissue irritation Teeth are one thing and gum tissue is a whole other subject… Our gums like to be stimulated. They like to be massaged. They don’t like chemical warfare or being tortured by poorly fitting mouth trays. These bleaching agents are meant for the teeth (even more specifically, tooth enamel). When these strong bleaching agents sit on our gum tissue, they fry it. Again, is it a permanent issue? No. Gum tissue can and will regenerate (think of how many times you’ve burned the roof of your mouth with hot pizza and the soft tissue sloughed off and recovered Dental Chair.) But again, why cause more stress to tissue that for most of us is challenged to begin with? Speaking of stressed tissue, if you tend to get canker sores, aggressive whitening strategies can make the situation much worse. At the risk of freaking you out, there is substantial research that suggests that high concentrations of hydrogen peroxide (like those used in dental office applied bleaching) can increase risk of oral cancer. Much more on hydrogen peroxide and concentrations below. Risk of losing enamel Losing enamel is serious. According to the European Journal of Dentistry, “All bleaching treatments… promoted a significant reduction in the micro hardness values [of enamel]”.(4) This study tested various strengths of bleaching treatments along with some that used special lights to accelerate the ‘in office’ bleaching treatment. The study found that there was up to an 8.5% loss of hardness of enamel 24 hours after bleaching. The amount of loss of enamel hardness directly related with the strength of the bleaching agent used. In other words, the higher the concentration of bleaching agent, the higher the loss. There was an 8.5% loss when using 35% hydrogen peroxide + light compared to only a 1.3% loss when a 15% concentration and no light was used. The good news is our bodies are always repairing the crazy damage done to them. That’s the case with this loss of enamel micro-hardness too. Within a week, the body has remineralized the loss and teeth are back to their ‘normal’ hardness.  Why Is Dental Care During Pregnancy Important? for more information.