Updated: Sep 10, 2020
Internal tooth stains cannot be diminished with traditional whitening methods.
Intrinsic discolouration originates from the pulp chamber or the dentin. Pulp degradation is followed by hemoglobin breakdown. When this breakdown is in the pulp horns (the section of the pulp that goes into the visible part of the tooth), it changes the look of the tooth externally.
A trauma to the tooth or deep caries can cause the pulp to die. The lack of blood supply impact the tooth’s internal anatomy, changing the way light transmits through its layers. This leads to a darkened appearance and reduction in lustre.
Minor or major carious lesions cause discoloration ranging from light yellow to dark black. Sometimes these lesions can reclassify into a lighter white or dark black.
Overall, caries and subsequent cavitation leads to a deeper changes in morphology and anatomy. Yet again, this change the optical properties of the tooth, changing its color and luminosity.
Antibiotics like tetracycline can become embedded within the tooth structure if they are ingested during tooth development. For this reason, tetracycline is contraindicated for pregnant women and young children. Crowns of certain teeth (the top, visible part of the tooth) continue to develop until approximately 8 years of age. If ingested, this antibiotic binds to the calcium within the developing tooth. This leads to tooth discolouration.
When a tooth gets a non-surgical root canal treatment (aka root canal), the material used to close off the canal can change the color of the tooth. The main reason for this is that the gutta percha (the root canal filling material) is left too “high” into the crown space.
In order combat internal tooth stains, you usually need an advanced procedure. Veneers, crowns, and site-specific fillings an all be utilized to restore your smile.