Writing about what’s wrong with conventional treatments has never been a favorite for us.
As many of you who regularly read our articles know, we much prefer to discuss solutions to help each of us navigate the path to greater oral health.
So, it’s in this spirit to help you along your path to a happier, healthier mouth that we share our research on the various risks of conventional teeth whitening treatments.
This article follows on the heels of previous articles where we detail what we consider the first step to naturally whitening your teeth as well as lay a foundation of the various methods and strategies used to whiten teeth.
These previous articles really do set the stage for this continued discussion. While you can read this article first, you’ll get more out of it if you read the previous articles first.
The ‘official’ word on the risks of conventional tooth whitening treatments states that the two common complaints are increased tooth sensitivity and gum tissue irritation.
However, digging further into the research exposed that there are many other very real concerns about whitening treatments including:
- tooth surface roughening and softening
- increased potential for demineralization
- increased risk of tooth fracture
- degradation of dental restorations
- unacceptable color change of dental restorations
So, let’s make our way through understanding what’s really behind these complaints and risks to help you determine if conventional teeth whitening treatments can be part of your oral health plan.
(Quick note: While we researched many clinical studies for this article, the main resource we reference–and arguably the most respected compilation on this subject–is “Hydrogen Peroxide, in its free form or when released, in oral hygiene products and tooth whitening products” which was published by the European Union Scientific Committee on Consumer Products in 2007.)
How common are the complaints?
In a large survey of dentists, 91% of 8,143 dentists stated that they had used tooth bleaching in their practice. Here’s the tally of the side effects reported to these dentists. 62.2% noted tooth hypersensitivity, 45.9% reported soft tissue irritation, 2.1% noted systemic effects, and 18.8% reported no side effects. (1)
Increased tooth sensitivity
Hands down, the #1 complaint about bleaching treatments is increased sensitivity.
This makes total sense when we consider that teeth are porous and have tiny holes on their surface. Bleaching agents travel through these tiny holes and penetrate the tooth surface oxidizing any staining agents on their journey into the teeth. This is why bleaching chemicals work to whiten our teeth. They bleach these tiny pathways through our teeth.
In another study, volunteers used either home based or dentist delivered whitening techniques. Results showed that up to 70% of the volunteers experienced sensitivity and 13.8% of the participants actually withdrew from the study due to mouth pain. (2)
What the post whitening sensitivity is really saying…
The research shows that bleaching agents cause an inflammatory response in the deepest layers of our teeth (at the junction of the dentin and tooth pulp). This inflammation corresponds to the pain patients have from whitening treatments.(1)
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.)
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).
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.
But at what cost? What damage can be done while the enamel is in this ‘less that optimal’ state of hardness? Aren’t most of us trying to maintain decay free mouths without this insult to enamel hardness?
Permanent Enamel Loss – The Hidden Risk of Whitening
In this most recent section above, we discussed how enamel micro-hardness was reduced up to 8.5% 24 hours after a bleaching session and that enamel hardness was back to ‘pre-whitening’ levels after a week.
Several studies show a significant risk of permanent enamel loss due to abrasion of weakened enamel due to bleaching. One study states there is a “significant increase in enamel wear following treatment protocols”. And, this particular study used hydrogen and carbamide peroxide concentrations that are on the lower end of those used commercially. (1)
What all this means to us is that bleaching causes a temporary softness of tooth enamel and if we brush unconsciously, we run the very real risk of removing enamel.
This situation can become a vicious cycle because loss of enamel is one of the main reasons that our teeth discolor with age. So, we bleach more and lose more enamel which further causes discoloration, etc.
Risk of Tooth Fracture
(Special word of caution for anyone with gum recession…)
Up until now, we’ve been talking about the potential risks of bleaching agents mostly on tooth enamel. However, once a person has some gum recession, this means that they have exposed dentin (where the gum tissue has receded from).
And dentin isn’t as hard as enamel…
So, teeth with exposed dentin (like in the case of gum recession) are at an increased risk of fracturing. None of us want to experience a tooth breaking while we are chewing on it…
One study tested the relative strength of dentin after bleaching and found a significant reduction in fracture resistance.
In the closing statement of one study, the authors state, “caution should be considered when using bleach for prolonged treatment times in clinical cases where there is dentin exposure such as gingival recession.” (5)
Are Bleaching Treatments Really that Bad?
We have to state that many studies show little difference and insignificant risks from bleaching. However, we feel that some of this can be attributed to the fact of who is sponsoring the study and the resulting ‘spin’ how the study is created to produce the results that industry desires. Also, there are significant differences between how all these studies were set up, what parameters were used, etc which can cause two different studies to come up with very different conclusions.
That said, even the studies that ‘show no negative results’ state, “Numerous studies have indicated negligible changes in enamel surface texture associated with peroxide bleaching. When changes are observed, they are for the most part minor, involving the formation of shallow depressions or increased porosities. These are likely to be a side effect of the bleaching matrices.” (6)
Uh, I don’t know about you, but I don’t consider shallow depressions or increased porosity of my teeth negligible.
Special ‘Under the Bus’ Award for Chlorine Dioxide
According to Linda Greenwall, a dental specialist in the UK who literally wrote the book on tooth whitening, “these products are causing harm to teeth”.
Greenwald explains that the problem with chlorine dioxide is it’s very acidic (ph of 1-3!). So, when chlorine dioxide is used on the teeth for bleaching, the damage is compounded. “Placing this directly on teeth can result in permanent etching of tooth enamel.”
“Damaging effect of chlorine dioxide whitening treatment on teeth: etching of teeth, loss of tooth luster, teeth appearing more discolored, teeth absorbing more stains than before (due to loss of protective enamel), teeth feeling rough, increased sensitivity (sometimes permanent).” (7)
With all this said, how can OraWellness suggest using hydrogen peroxide?
First off, it’s super important that we clarify that we ONLY endorse the use of hydrogen peroxide in the mouth at a maximum concentration of 1.5%. As many of you Healthy Mouth System users know, we commonly teach to start with a 1.0% hydrogen peroxide solution.
You see, concentration does make a HUGE difference.
It’s important for us to grasp that some of the cells that make up our immune systems create hydrogen peroxide to use to defend us from ‘thug bugs’. So, it’s not that hydrogen peroxide is bad or good. The concentration plays a big role whether anything is health giving or destroying.
For example, we all know that drinking water is good for us. But you can drink too much water and actually drink yourself to death. It’s called dilutional hyponatremia. Strange but true.
To support this statement, let’s reflect on this study on the ability of hydrogen peroxide to penetrate tooth tissue and reach the tooth pulp… Peroxide was detected in the pulp cavity as early as 15 minutes following exposure of enamel to 10 or 30% hydrogen peroxide, and the amounts detected showed a significant dose relationship. (8)
Long-Term Implications of Whitening Treatments
Let’s close by keeping in mind that our teeth are meant to last a lifetime provided we care for them well. One last study concluded that, “the results indicated a need to warn patients of the potential for enamel alteration and its detrimental effect on tooth structure even if the long-term consequences have yet to be conclusively determined.” (9)
“So is bleaching safe or not?”
We have attempted to present the research here so you can make an educated choice whether conventional whitening treatments are safe for you or not. This is a value judgment mostly based on how deeply you want to whiten your teeth compared to the risks as you understand them now.
If you choose to bleach…
Learning from this research into the studies on teeth whitening, there are things we can do to help mitigate the potential risks of bleaching. Here are some quick ‘takeaway’ gems.
- Use LOW concentrations. Don’t be sold on the safety of high concentrations of bleaching agents. While there are plenty of studies that ‘prove’ their safety, there are many other studies that suggest a more conservative approach is wise. Think marathon, not sprint.
- Brush consciously after bleaching. Yes, you want to keep your white smile white, but just be really conscious about how you brush because there is a very real risk of brushing your enamel off. Also, be cautious using pastes or powders that are ‘whitening’ as they very well may be more abrasive which could make the enamel erosion even more extreme.
- Choose carbamide peroxide (low concentration). Studies show that carbamide peroxide penetrates the teeth less which feels better to us regarding the impact on tooth pulp. This suggests that carbamide peroxide causes less inflammation to the tooth pulp and is therefore less irritating.
Our final word on the risks…
Similar to our stance on the use of fluoride in the mouth, if these conventional whitening treatments were the only way to have a naturally whiter smile, we would have to take a closer look regarding whether they were ‘worth the risk’ to us. Thankfully, there are strategies that we all can apply to help us have a whiter smile that don’t compromise the health of our teeth and gums.
We will share our findings of strategies how to have a naturally whiter smile without compromising your tooth enamel in upcoming articles.
Now it’s your turn…
Have you tried conventional teeth whitening methods (at home or dental office applied)? If so, what was your experience? Did you experience any of the risks above?
Please share so we can all continue to learn from one another.
Helpful, Related Resources: