Carbamide Peroxide vs Hydrogen Peroxide

You must have heard about hydrogen peroxide when it comes to teeth whitening. However, in some instances, dentists may use the milder version for whitening i.e. carbamide peroxide.

Over-the-counter whitening products usually contain carbamide peroxide while in-office procedures may mostly use hydrogen peroxide as the primary whitening agent.

While hydrogen peroxide is a main whitening agent, carbamide peroxide also contains hydrogen peroxide in a 1 to 3 ratio. For every 30 percent of carbamide peroxide, there is 10 percent of hydrogen peroxide.

This article discusses the differences between the two so you know what bleaching agent you need in your whitening treatment.

Keep reading below!

Knowing Hydrogen Peroxide

H2O2 or hydrogen peroxide is a very reactive, pale blue in color, a chemical compound.

In order to use it, you need to heavily dilute it with water.

Its use in teeth whitening comes from it being very reactive to oxygen.

The oxidization makes it effective in removing stains and killing bacteria.

The hydrogen and oxygen in the compound have an oxidizing and reducing effect.

Though, it is important to use it only in its diluted form.

H2O2 is a very strong chemical that has dangerous implications if not used in diluted form.

Once diluted, it’s used in whitening as a bleaching agent but also for bleaching hair, cleaning households and disinfecting cuts.

What makes hydrogen peroxide an extremely efficient whitening agent is how fast it breaks down.

Due to that it quickly whitens the teeth within an hour or half of the application.

Dentists may use a gel with a higher concentration of hydrogen peroxide in in-office dental whitening treatments.

However, the at-home whitening kits usually contain a lesser percentage of the compound so that it applies safely and does not pose side effects.

Due to its quick action, hydrogen peroxide may be a preferable option for home whitening kits to use at daytime and the clinical whitening kits.

Now that you know hydrogen peroxide, let’s find out about carbamide peroxide and how it affects your teeth in the whitening process.

What is Carbamide Peroxide?

Carbamide peroxide is technically a chemical that contains hydrogen peroxide with urea.

The chemical compound gets its name from the two because the other name for urea is carbamide.

It fulfills the same purposes as hydrogen peroxide such as a bleaching agent for whitening to break down the chemical composition of stains, household cleaning, and hair bleaching but differently.

The difference arises when carbamide peroxide breaks down more slowly than hydrogen peroxide. Though there are many others too that we will discuss later.

When it comes to breaking down the stains, carbamide peroxide releases around 50 percent of the whitening effect during the first 2 hours of application.

The effect of carbamide peroxide on the other 50 percent only happens over the period of the next 6 hours.

When carbamide peroxide is in contact with teeth it releases hydrogen peroxide.

As the latter has a strong oxidizing and reducing effect, it acts as a bleaching agent releasing free radicals such as H+ or H3O+.

Thus, the slow action of whitening in carbamide peroxide can make it a popular choice for in-office whitening but also for nighttime home kits.

However, your dentist may choose what will give the best results.

For that let’s find out what are the differences between the two and the similarities that make them equally good for use in the process of teeth whitening.

Similarities

Since both of these are peroxide-based agents, there are tonnes of similarities between the two.

Essentially carbamide peroxide is the diluted version of the same hydrogen peroxide.

The diluted version is used because it reduces risks and side effects, especially when a non-professional uses it.

Hence, when it comes to certain factors, they display similarities. Such as:

Results 

The results are more or less the same for both carbamide and hydrogen peroxide.

The difference arises when one archives a better result in the beginning (H2O2) and the other is for maintaining the whiteness i.e. carbamide peroxide.

Nonetheless, both are used for whitening and are effective when it comes to the procedure.

Sensitivity 

Tooth sensitivity is an unavoidable side effect of whitening treatment.

Whether it is hydrogen peroxide and carbamide peroxide both can result in sensitivity.

Moreover, there is no difference in the amount of sensitivity that the two cause.

Oxidizing agents 

Both of these are oxidizing agents as they are reactive when they get oxygen exposure.

In fact, it is through this oxidizing process due to they break down stains and whiten the teeth removing all the yellow, and brown discoloration.

Does Not Result in Rebound 

Rebound is when the teeth usually look whiter immediately after whitening but that is due to dehydration.

This means they tend to lose brightness shortly afterward.

Both of these do not cause rebound, however, it also depends on the product you use.

Since it has more to do with dehydration rather than peroxide base levels, the gel you use should have a higher water content to prevent rebound.

Carbamide Peroxide vs Hydrogen Peroxide

Shelf Life 

Usually, products that contain hydrogen peroxide have a shorter life span than those containing carbamide peroxide.

Hence, carbamide peroxide has a longer shelf life but that of hydrogen peroxide can also be extended.

For that, you will have to refrigerate it.

Chemical Composition 

The main difference between the two is in their composition.

Hydrogen peroxide consists of hydrogen and oxygen whereas carbamide peroxide consists of urea and hydrogen peroxide.

For every 30 percent of carbamide peroxide, there is 10 percent of hydrogen peroxide in it.

Hence, both are different when it comes to their chemical composition however, their effectiveness is usually the same.

That said, the way they decompose and at what speed carry out the procedure differs too.

Speed of Decomposition 

Carbamide peroxide consists of urea which stabilizes its mixture and also increases the time of its effectiveness.

Hydrogen peroxide does not contain urea so it decomposes faster.

Usually, hydrogen peroxide will release its whitening ability during 30 to 60 minutes of application on teeth.

Therefore, rapidly whitening teeth.

Hence, products containing hydrogen peroxide are usually kits that promise fast action.

Daytime kits and clinical kits contain hydrogen peroxide for this reason. 

On the other hand, carbamide peroxide has a slow release of whitening effect.

It will release half of the whitening power in peroxide in the first two hours.

The other half will be released gradually in the next six hours.

This is why the use of carbamide peroxide is popular in nighttime whitening kits. 

The slow release allows for whiteness to have a lasting effect.

Risks 

Since hydrogen peroxide is very reactive it can damage cell walls and other materials it touches.

Therefore, dentists may prefer using carbamide peroxide instead because it does not decompose as fastly posing risks to surrounding areas.

Advantages and Disadvantages

While these two have similarities and differences, they also have their own set of advantages and disadvantages.

The disadvantages may give each other an edge over the other.

Advantages of Carbamide Peroxide 

Carbamide peroxide gives a good result so it is an effective whitening agent.

What’s more, it is also safe to use.

It will not lead to a color rebound after whitening especially if the gel contains a high water content avoiding any dehydration.

Moreover, it has a long shelf life so it can stay unused for a longer time.

As it takes 2 hours and then the next 6 hours to fully decompose, it is active for longer in the mouth.

That has its own pros as there is more time to whiten teeth at a gradual rate and also it can kill bacteria in your mouth in the meanwhile.

Advantages of Hydrogen Peroxide 

As the two are similar in many aspects, they have similar advantages as well.

Hydrogen peroxide is an effective whitening agent.

In fact, it breaks down faster so it gives quicker results.

You can see a noticeable change in your teeth by an hour.

Moreover, it does not cause color rebound after teeth whitening.

Disadvantages 

• Carbamide Peroxide

While it is usually safe to use, a higher concentration can be damaging to the enamel.

It takes longer to break down carbamide peroxide hence, the treatment sessions that use it take longer time overall.

• Hydrogen Peroxide

It is very reactive.

That allows hydrogen peroxide to produce fast results but it can also be damaging to the enamel if the concentrations are really high.

Also, it has a shorter shelf life.

You may extend the shelf life by keeping it in a fridge but that is an overall disadvantage as it won’t last long otherwise.

What to Choose: Carbamide Peroxide or Hydrogen Peroxide?

When it comes to choosing between the two, your dentist will evaluate the condition of your teeth and there you need a fast-acting or a steady-acting peroxide base.

You will also find the two peroxide bases in different teeth whitening kits.

Again, make your decision depending on whether you want to wear it in the daytime or nighttime and can invest some time or want quick results.

Both the peroxide bases have their set of pros and cons, similarities and differences, however, usually both give equally effective results.

Ask your dentist what home whitening kit and in-office gel will whiten your teeth well and choose between carbamide peroxide vs hydrogen peroxide considering n their differences and your dentist’s recommendation.