The early stages of a dead front tooth can be successfully treated with at home whitening since it starts as mild discoloration. However, once it progresses to the later stages, the color can darken beyond what over the counter methods can treat.
For severely discolored non-vital front teeth, professional whitening by your dentist is required. Although the type of whitening that your tooth needs is NOT the one that you're thinking of because this condition needs internal bleaching.
How to whiten dead front teeth
When external whitening (vital teeth whitening) is ineffective, the last resort option to whiten your dead front tooth is by using internal bleaching. The technique is called the walking bleach protocol.
Here is what to expect when you whiten the tooth internally:
Take clinical photos and a tooth shade to be used as reference.
Place rubber dam isolation.
Create an access opening through where the root canal was first done.
Clean out the cavity of any residual debris as well as root canal filling material down to approximately 2-3 mm below the gum level.
Place a 2-3 mm layer of glass ionomer, cavit G, IRM, or zinc phosphate cement on the pulpal floor. This is to protect the root from the bleaching gel.
Mix sodium perborate with water until a wet sand consistency.
Place the mixture inside of the tooth.
Seal off the cavity with cavit G that is at least 2-3 mm thick.
Have the patient return in 3-10 days to remove the old whitening material and replace with a fresh mixture.
Steps 1-9 can be repeated for up to 4 times.
It is important that the patient monitors the bleaching progress on a daily basis. If the tooth reaches the desired whiteness level, they should return to the dentist sooner to have the bleaching inside of their tooth removed. This is to prevent over-whitening the tooth.
After all, the goal is to have the tooth match the adjacent teeth in terms of color. The purpose isn't to get the front tooth as white as possible because then you'd have the opposite problem.
Other whitening techniques
The walking bleach protocol above is the most common and safest way to do it. However, there are slightly different techniques that can be used as well.
Walking inside out technique. This method is similar to the walking bleach except your dentist will make you whitening trays. They will also leave the access opening to the inside of the tooth exposed. You're supposed to use the trays to whiten the exterior and interior of the tooth at the same time. The downside to this method is that food can get stuck inside of the hole.
Inside outside in-office technique. This technique is basically in-office whitening. Your dentist will drill a hole through the back of your front tooth. They will then place whitening gel on the outside and inside of the tooth. Leave it for 10-15 minutes and replace with a fresh solution. They will repeat this 4x and then you're done. The plus side to this technique is that you're not "walking" and "bleaching" because everything is completed in a single office visit.
Efficacy of whitening
Typically, dentist intervention is required for the whitening of substantial tooth discoloration because at home products aren't sufficient. Fortunately, the internal tooth whitening does seem to be effective and patients are satisfied with the results.
87.8% of the test subjects were very satisfied with the results.
7.32% were simply satisfied.
4.9% were unsatisfied.
Overall, the average shade change for the study was about 11.97 shades of color. The results indicate that internal bleaching of anterior teeth is an effective but conservative treatment modality.
Comparison of different internal bleaching techniques
Bleaching your teeth internally can be done via various ways but the results from multiple studies seem to indicate that the results were similar. There weren't any significant differences in the end result for color change among the various methods used.
Compared 3 different methods of whitening:
Group A = traditional external whitening with 10% carbamide peroxide
Group B = internal whitening with sodium perborate mixed with 3% hydrogen peroxide (modified walking bleach technique)
Group C = internal and external whitening with 10% carbamide peroxide
Initially group C was significantly better but after six weeks, the results were equivalent.
Tested 3 different mixtures of sodium perborate and how they whitened:
Sodium perborate with 30% hydrogen peroxide
Sodium perborate with 3% hydrogen peroxide
Sodium perborate with water.
After 14 days of internally bleaching the tooth, there were no significant differences among all three groups.
Initial impression was that the 30% hydrogen peroxide should provide a superior result but it turns out that it didn't make a difference.
Overall, the conclusion seems to be that you should simply use the "safest" internal whitening method which is the sodium perborate with water. That is the least likely to cause post-bleaching external root resorption, which is a major risk for this procedure on dead teeth.
Alternatives
If attempting to whiten the tooth internally does not work or you don't want to do it, the only alternative would be to cover it with a porcelain restoration. This means you can either place a crown or a veneer over it to mask the color.
Dental crown. The entire tooth can be shaved down and then covered with a porcelain restoration. This is the most invasive option but is a good choice if the tooth has a lot of existing fillings already.
Veneer. If the tooth does not have any restorations on it, a veneer will be a more conservative option. This procedure only requires shaving down the front half of the tooth instead of preparing it 360 degrees.
Both of these alternatives will work but they are irreversible in that you can't unshave the tooth afterwards. That is something to keep in mind.
Risks
The major risk and complication of internally bleaching a dead front tooth is potential external root resorption. That is a condition when your body starts to resorb your tooth's roots, it is essentially being dissolved. The ultimate consequence is that you may lose the entire tooth.
According to the American Dental Association, using 30% hydrogen peroxide may provide very good immediate effects but success drops below 50% in the long term. Use of such a high concentration of peroxide has demonstrated this adverse effect, both experimentally and clinically.
The ADA recommends that you only use sodium perborate mixed with water since that minimizes the chances of it occurring.
Concurring evidence
A systematic review also came to a similar conclusion as the ADA. They also recommended against the walking bleach technique and to use the combined technique instead.
They also gave a couple of additional precautions:
Remove root canal filling material to 3 mm below the amelocemental junction.
Place calcium hydroxide covered with glass ionomer cement to seal off the entrance to the root canal. This is to prevent the peroxide from diffusing down the root.
After finishing the bleaching, place calcium hydroxide into the pulp chamber to neutralize remaining peroxide.
Overall, they also recommended sodium perborate as a better alternative to pure hydrogen peroxide. Studies show that it reduces the risk for root resorption.
The potential increase in safety may have to do with the difference in the pH of the whitening agents. One of them is much more acidic than the other.
Hydrogen peroxide has a pH value of 2-3 which is very acidic.
Sodium perborate has a pH value of 10-12 which is basic.
Before and after
Whitening the front teeth by placing the bleaching gel inside of the tooth does work. There have been many cases of the tooth lightening enough to return to its original shade. In fact, you have to monitor the bleaching very carefully because you can potentially whiten it more than the adjacent teeth.
For before and after clinical photos, please check out this study which includes a case report. They document the entire treatment from start to finish. That means there are photos as to what it looks like before and after the internal whitening treatment.
If you wanted additional images you could also check out ultradent's opalesence endo which is one of the internal whitening products. They do provide photos of the steps of the treatment as well as what the teeth look like after treatment.
Why dead teeth change colors
Most commonly, the discoloration of dead teeth is due to the intracoronal decomposition of blood. Basically, all of the blood inside the crown will disintegrate and that is what causes the darkening of your front tooth.
Of course, these effects don't happen immediately because it may take many years before the color even becomes noticeable to you. It is a very slow and gradual process. More often than not, it is usually your dentist who points it out to you during a check up visit.
That is everything that our dentists in Long Island City have to say about how to whiten a dead front tooth.
