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Teeth Whitening Risks and Complications

Potential Complications

Teeth whitening treatments are considered to be safe when procedures are followed as directed. However, there are certain risks associated with bleaching that you should be aware of:

  • Sensitivity: Bleaching can cause a temporary increase in sensitivity to temperature, pressure and touch. This is likeliest to occur during in-office whitening, where higher-concentration bleach is used. Some individuals experience spontaneous shooting pains ("zingers") down the middle of their front teeth. Individuals at greatest risk for whitening sensitivity are those with gum recession, significant cracks in their teeth or leakage resulting from faulty restorations. It has also been reported that redheads, including those with no other risk factors, are at particular risk for tooth sensitivity and zingers. Whitening sensitivity lasts no longer than a day or two, but in some cases may persist up to a month. Some dentists recommend a toothpaste containing potassium nitrate for sensitive teeth.
  • Gum and soft tissue irritation: Whitening may cause inflammation of your gums, lips or cheek margins. This is generally the result of the whitening gel coming into contact with these tissues. If any irritation does occur, it is generally short in duration and is very mild. The affected gums may also appear white, but this too will resolve over time. Rinsing with warm salt water can help relieve any discomfort.
  • Existing Restorations, and Uneven teeth colour: Restorations like white fillings, dental crowns, or veneers remain unaffected by teeth whitening and retain their initial color. Only your natural adjacent teeth can be whitened, potentially causing an uneven tooth color across your teeth. Your dentist will have discussed this with you, and it may necessitate replacement of these restorations after whitening.
  • Defective fillings/Cavities: If fillings and tooth, which may cause some discomfort. In the worst case it may lead to the need for root canal treatment. It is strongly advised any cavities, decay, defective fillings are replaced before any cosmetic tooth whitening is carried out.
  • Stubborn Stains: Teeth whitening treatments are highly effective in removing many types of stains, particularly those caused by surface discoloration from food, drinks, or smoking. However, some stains may be more resistant to whitening agents. For example, intrinsic stains that originate within the tooth structure, such as those caused by certain medications or dental trauma, may not respond well to traditional teeth whitening method, and there may not be a significant change in colour of these teeth.

  • Tooth Color Variability: Not all teeth are the same shade naturally. Some individuals have teeth that are naturally more yellow or gray in color. Teeth whitening can improve the brightness of these teeth, but they may not achieve the same level of whiteness as teeth with a different natural color. Additionally, teeth with thin enamel may have limited whitening potential.