Cone beam computed tomography

A small‐volume cone beam computed tomography (CBCT) scan of tooth UL1 was taken to assess the location, size and spread of the periapical lesion. There was a large periapical radiolucency and associated thinning of the buccal alveolar plate (Figure 6.3.3).

What is extrinsic staining?

Extrinsic staining is staining of the outer enamel surface that can be removed and is the result of topical or extrinsic agents.

What are the factors predisposing to extrinsic staining?

• Enamel defects: Pits and defects can accumulate substances.
• Salivary dysfunction: Saliva helps remove food particles and plaque, which cause discoloration.
• Poor oral hygiene: Plaque and calculus build up results in black and brown staining.

What are the causes of extrinsic staining?

• Food and beverages: Coffee, tea and wines contain tannins, which result in brown staining. Foods containing polyphenols also can cause discoloration.
• Tobacco: Smoking cigarettes or cigars or chewing tobacco results in very dark brown and black stains, usually involving the cervical third to half of the tooth.
• Chromogenic bacteria: Bacterial species such as Actinomyces result in black staining due to poor oral hygiene. Fluorescent bacteria and fungi (Penicillum and Aspergillum) can result in green staining.
• Topical medications: Chlorhexidine/stannous fluoride can lead to brown staining.
• Metallic compounds: Exposure to iron, manganese and silver can result in black staining.

How are pigmentations classified?

Pigmentations are classified as follows:

• N1: Direct dental stain binding to tooth surface chromogenically. Chromogens are coloured particles that adhere to the enamel, e.g. coffee, tea, wine, metals and bacterial products.
• N2: Direct dental stain, whereby the chromogen changes colour after binding to the tooth.
• N3: Indirect dental stain, where a colourless pre‐chromogen undergoes a chemical reaction after binding to the tooth, resulting in a stain.

What is intrinsic staining?

Intrinsic staining is discoloration incorporated into the structure of the tooth and cannot be removed physically. This can be in the enamel and/or the dentine and has varied distribution (regional, generalised, primary or secondary teeth).

What are the pre‐eruptive causes of intrinsic staining?

• Tetracycline staining:
  • Susceptibility occurs in the second trimester in vitro → eight years post birth.
  • Severity/degree of staining is dependent on time and duration.
• Systemic conditions:
  • Hyperbilirubinemia results in bilirubin deposition in the enamel and dentine.
  • Erthyropoietic porphyria increases porphyrins, resulting in erythrodontia.
  • Amelogenesis imperfecta, caused by mutations of AMELX, ENAM or MMP20 genes.
  • Dentinogenesis imperfecta, caused by changes in the DSPP gene.
  • Enamel hypoplasia, caused by vitamin A, C, D and calcium and phosphorous deficiency.
  • Alkaptonuria, an inherited metabolic disease.