Internal Bleaching

If you have a tooth with trauma, dead pulp, or an old root canal treatment, you might notice your tooth becoming darker, more fragile, or having a different appearance than other teeth around it. ​Darker teeth can be easily fixed with internal bleaching or inner teeth whitening techniques.

Standard teeth bleaching Vs internal bleaching

Chemical teeth whitening is often called bleaching, referring to the process of whitening the tooth color to a brighter shade using chemicals that oxidize the tooth’s organic pigments, which bind to the enamel and dentin surfaces. Bleaching may be done either internally or externally.
Chemical teeth bleaching works on the outer surface of the tooth structure to dissolve teeth discolorations and stains from smoking, mild fluorosis, or colored foods, while internal bleaching works from the inner surface of the tooth to remove the darker shade of the tooth from inside the tooth.

Internal teeth bleaching can be applicable only if the tooth has undergone root canal treatment as a treatment for intrinsic stains caused by trauma, pulp necrosis, such as in dead teeth, and internal bleeding. 
Blood clotting and old endodontic filling stains inside the tooth don’t easily dissolve with laser teeth whitening and bind with the dentin particles, which causes darker shades from inside the tooth.

In this situation, internal bleaching for root canal teeth is the only dental treatment that can whiten and lighten the darkened tooth by penetrating and dissolving the stains directly.

When can you get internal tooth bleaching?

Laser teeth whitening is effective on superficial stains, while internal teeth whitening effectively dissolves and eliminates the internal stains from the inside out.
If there is tooth damage, internal tooth bleaching is indicated in the following cases:

• If a tooth has experienced trauma, cracks, or a tooth fracture, leading to internal discoloration or pulp damage.
• Internal bleaching is used after pulp therapy because the tooth may gradually become darker over time, and internal bleaching can help to recover its natural shade. 

• Intrinsic discoloration: it takes place inside the tooth. It can occur due to several reasons, such as medicines or developmental problems. In this case, a root canal therapy should be performed first, and then followed by internal bleaching. 
• In a Hollywood smile makeover for extremely dark teeth, if you are getting a much lighter and whiter smile with Emax veneers, dental lumineers, or ceramic crowns, and the abutment tooth is darker in shade and badly affects the white shade of the restoration. An internal bleaching agent is applied two sessions before covering the teeth with veneers.

Steps of internal teeth whitening 

There are several techniques for internal teeth whitening; they all start with the tooth having a proper root canal therapy, then a sealant barrier over that endodontic filling. 

This seal is mandatory to confirm the sealing of the root canal treatment and minimize any risk of bleaching agent escaping through the root canals.

Then, the dentist cleans and removes any debris, blood clots, dental fillings, or remnants of old root canal sealer from the coronal part of the pulp chamber (the inner surface of the cavity in the crown of the tooth).

Finally, the bleaching agent is gently inserted into the inner side of the tooth crown in an adequate amount.

 In both external and internal teeth whitening, you should follow the teeth whitening aftercare instructions for better results

Techniques of internal teeth bleaching

In-office Laser-assisted Bleaching (chairside technique)

It’s one of the uses of lasers in cosmetic dentistry; dental bleaching is one of the cosmetic procedures done chairside. The dentist cleans the coronal part of the tooth crown properly, removing any remnants of root canal filling, then protects the root with a protective, tight barrier. 

The whitening agent used with laser activation is high-concentration whitening gel (e.g., 35%- 40% Hydrogen Peroxide), like Opalescence Boost (by Ultradent), Zoom! (by Philips), Smartbleach® Teeth Whitening.

The “Walking Bleach” Technique

One of the most conservative and common methods for treating deep, localized stains. It delivers excellent results with minimal chair time.

Before starting, an X-ray is mandatory to evaluate the existing root canal filling. If the seal is inadequate, it must be replaced and allowed to fully set for at least 7 days. Once cleared and the protective sealant applied, the dentist places a preformed chemical whitening agent inside the tooth cavity, like white dental beauty by Optident Opalescence™ Endo by Ultradent, which is the market leader for ready-made, non-vital “walking bleach” gels

The patient goes home while the agent works actively “on the walk.” After a few days, the dentist evaluates the shade progression and repeats the process until the tooth matches the surrounding dentition.

Inside-Outside Bleaching (At-home technique)

This dual-action approach combines internal treatment with traditional home-use kits. The dentist leaves the internal pulp chamber intentionally open, and the patient uses a custom-fitted whitening tray at home. The patient applies a chemical bleaching agent, specifically carbamide peroxide, both inside the open tooth cavity and externally inside the tray, using gels like Pola Night by SDI (High Concentration Carbamide Peroxide).
This simultaneous treatment accelerates the breakdown of stubborn pigments from both sides of the tooth wall.
Though this chemical bleaching agent is gentle and less harmful, this technique relies on patients’ compliance and the amount of bleaching agent inserted in the tray. 

Thermocatalytic Bleaching (Old technique)

This method was very effective with a quick result, but has largely fallen out of favor due to specific clinical risks.
The dentist inserts a powerful oxidizing mixture (typically sodium perborate and hydrogen peroxide) directly into the pulp chamber. Heat is then applied using specialized lamps or electric heating devices to accelerate and intensify the chemical reaction.
This cycle is repeated 3 to 4 times per visit. However, because studies have linked intense heat application to an increased risk of cervical root resorption (spontaneous breakdown of the tooth structure near the gumline), this method is rarely the first choice in modern dental practices.

Risks of internal teeth bleaching

Internal bleaching involves the removal of all filling materials from the access cavity. It must be done carefully to avoid further removal of the dentin itself; it may result in the following risks:

• Gum and oral tissues irritation
  Some people may have sensitive teeth as a result of the minimal leakage of the bleaching materials, which can irritate and burn the gums, but this is mostly temporary and can be avoided by properly sealing the root with a seal.
• Tooth Structure Weakness
  Multiple bleaching treatments and excessive removal of restorative material may weaken the teeth’s structural integrity.
  If there is a cemented fiber post in the root canal to support the tooth, and the pulp chamber was filled with composite resin, cleaning the access cavity could reduce the quantity of the tooth structure and make it weak.
  Some studies suggested that fluoride pre-treatment on the tooth surface reduces the risk of adverse effects and increases remineralization of the tooth. 
• Discoloration Relapse
  In some instances, there is a possibility that the color of the teeth will revert to its original color, requiring further bleaching treatment to keep the teeth white.
• Cervical resorption
  One study reported cervical resorption in approximately 3.9% of internally bleached teeth, with the incidence increasing in teeth with additional predisposing factors such as trauma or orthodontic treatment.
  The placement of a protective cervical barrier is often done before internal bleaching treatment because it helps prevent any possible leakage of bleaching material.

Best Alternatives to avoid internal bleaching complications

Selecting the right cosmetic solution will depend on your tooth’s functionality and cosmetic objectives. Here are alternative options other than internal bleaching:

• Denal veneers and Lumineers
  When your anterior teeth are structurally sound, but it appears discolored, dental veneers offer a perfect solution.
  In cases where root canal therapy was applied to anterior teeth, the application of veneers on the affected tooth’s enamel surface offers a natural smile without requiring maximum coverage with a crown. You can see our Hollywood smile with dental veneers offers and packages in Turkey.
• Direct Composite Veneers
  A tooth-colored composite bonding is applied to the external surface of the tooth to cover up any discolored areas while leaving the tooth relatively intact. Composite veneers are ideal for moderately discolored teeth and show excellent results
  At Suave Clinic, we use specific opaque composite layers that can hide darker shades from underneath before applying the esthetic layers.
• Dental crowns
  In cases where the tooth itself is fragile and susceptible to breaking after root canal therapy, the crown is definitely the way to go in ensuring that the integrity of the tooth is maintained, since crowns completely cover the whole tooth in order to protect and enhance its appearance. Dental Crowns are made using current materials such as porcelain, Emax Crowns, ceramic crowns, and zirconia crowns, which show a high translucency and brighter shade, that can be customized as the patient’s needs.