Tooth Discoloration: Causes, Treatment and Prevention

Discoloration Of Teeth Essay Questions

Question 1. Enumerate and briefly describe the various causes of discolored dentition.
Answer:

Generalized Discoloration of Teeth:

Two factors may cause generalized discoloration:

1. Intrinsic discoloration—Due to structural change in the enamel or dentin by either altered composition or poor mineralization.
2. Extrinsic discoloration—Due to the deposition of coloring agents on the teeth’ surface. It is subdivided into nonmetallic or direct staining and metallic or indirect staining. Combination of intrinsic and extrinsic discoloration.

Read And Learn More: Oral Medicine and Radiology Question And Answers

Generalized Intrinsic Discoloration:

• Genetic diseases:
  • Amelogenesis imperfecta—yellow- brown discoloration.
  • Dentinogenesis imperfecta and dentinal dysplasia—yellow.
  • Osteogenesis imperfecta—Brown opalescent teeth.
• Drugs:
  • Tetracycline: Tetracycline staining results from the chelation of calcium ions of the hydroxyapatite crystals as a stable orthophosphate complex. Tetracycline-stained teeth have a blue-gray or yellowish-brown appearance.
  • Minocycline: A semisynthetic derivative of tetracycline. Its prolonged ingestion causes green-gray or blue-gray discoloration of the teeth
  • Ciprofloxacin: When given to infants at dosages of 10-40 mg/kg/day give a greenish discoloration to the teeth.
  • Chlorhexidine mouth rinse: Prolonged use of chlorhexidine mouth rinse denatures the acquired pellicle on the teeth surface and releases sulfur radicals. These free radicals interact with the metal ions and form a metal sulfide complex and impart tooth coloration.
• Environmental:
  • Fluorosis: A daily fluoride ingestion of more than 0.07 mg/kg body weight/ day during early childhood period (at the enamel maturation stage) causes dental fluorosis. It is characterized by symmetrical patterns of discoloration resulting from subsurface hypo-mineralization.

• • Clinical appearance includes:
    • Generalized chalky white appearance.
    • Yellow-brown pitting.
    • Horizontal yellow-brown bands.
  • Metabolic disorders:
    • Hyperbilirubinemia—yellow-green.
    • Porphyria—Reddish-brown.
    • Alkaptonuria—Brown.
    • Neonatal hyperbilirubinemia may cause bilirubin deposition on the developing tooth buds producing a yellow-green coloration on the teeth known as chloro- dontia.
    • Congenital porphyria is an autosomal disorder of porphyrin metabolism, characterized by an increased formation and excretion of porphyrins. The porphyrin pigments have been incorporated into the calcium phosphate during tooth development, and these cause a characteristic reddish-brown discoloration of the teeth called erythrodontia. The affected teeth have red fluorescence under ultraviolet rays.
    • Alkaptonuria, (also known as phenyl-ketonuria or ochronosis) is an inborn error of tyrosine and phenylalanine metabolism resulting in an increased content of homogentisic acid. This results in a brown discoloration of the permanent dentition.
    • Molar hypomineralization (or) hypoplastic molars: All first molars may become severely hypomineralized with the appearance of a distinct yellow-brown color. The cause is idiopathic but proposed factors include childhood infections, dioxin in mother’s milk, or genetic factors.

Hereditary diseases causing tooth discoloration: Defective enamel formation may lead to intrinsic discoloration of teeth in the following conditions:

• Vitamin D-dependent rickets
• Epidermolysis bullosa
• Ehlers-Danlos syndrome
• Pseudohypoparathyroidism.

Single Tooth Intrinsic Discoloration

• Non vital teeth:
  • Pulp necrosis—Rupture of blood vessels in a traumatized tooth leads to leakage of RBC that undergoes hemolysis, and releases hemoglobin subsequently. Hemoglobin split into heme and globulin, and the iron in heme imparts a blue-black color to the crown.
  • Pulp degeneration—When there is no pulpal bleeding, the necrotic tissue undergoes protein degradation and gives a grayish-brown discoloration.
• Restorative materials: Amalgam restoration: The presence of tin in amalgam migrates into dentinal tubules and causes discoloration.
• Turner’s hypoplasia:
  • Local trauma or infection spread from the corresponding primary tooth may lead to chalky opaque appearance or brown discoloration, or enamel pitting on the permanent successor.
  • The permanent maxillary incisors and maxillary and mandibular premolars are the teeth commonly affected.

Extrinsic Discoloration of Teeth

• Occupational exposure to:
  • Iron and silver cause black staining of teeth.
  • Copper and nickel cause a green or blue-green discoloration.
  • Chromic acid fumes cause deep orange staining.
  • Lead dust and mercury imparts a blue-green stain.
• Poor oral hygiene: Brown discoloration by a pigmented pellicle deposition occurs on the facial surface of upper molars and the lingual surface of lower incisors.
• Tobacco stain: Deposition of coal-tar by-products of tobacco results in dark brown or black stains on teeth.
• Black discoloration by chromogenic bacteria: Black discoloration of teeth at the proximal and gingival margins are produced by Actinomyces in individuals with good oral hygiene. The reactions between the hydrogen sulfide released by the bacteria and iron in crevicular fluid cause black discoloration.
• Green stain: A band of green stain is produced by a fluorescent fungus, Penicillium that requires sunlight for growth. Hence, it produces discoloration only at the labial surface of the anterior maxillary teeth.

Discoloration Of Teeth Multiple Choice Questions

Question 1. Parkinson’s disease may cause

1. Blue sclera
2. Blue discoloration of the teeth
3. The blue line on the gingival margin
4. Bluetongue

Answer: 2. Blue discoloration of the teeth

Question 2. Penicillium and Aspergillus cause

1. Orange-stain of teeth
2. Slate color of teeth
3. Green staining of teeth
4. Brown discoloration of teeth
   (Note: Penicillium and Aspergillus cause green staining of anterior maxillary teeth).

Answer: 3. Green staining of teeth

Question 3. Chlorodontia causes green pigmentation of teeth by

1. Chloroquine deposition
2. P. aeruginosa colonization
3. Bilirubin deposition
4. Porphyromonas colonization
   (Note: Chlorodontia is a condition associated with hyperbilirubinemia, causing a green tint of teeth by bilirubin deposition).

Answer: 3. Bilirubin deposition

Question 4. Orange discoloration of teeth is caused by

1. Chromobacterium violaceum
2. Penicillium marneffei and Porphyromonas gingivalis
3. Cryptococcus neoformans
4. Flavobacterium and Serratia marcescens
   (Note: Orange discoloration of teeth is caused by chromogenic bacteria Flavobacterium and Serratia marcescens in children with poor oral hygiene).

Answer: 4. Flavobacterium and Serratia marcescens

Question 5. Orange-red discoloration of restored teeth is caused by

1. Tricalcium silicate cement
2. Grossman’s cement
3. Rickert’s sealer
4. Cohen’s sealer
   (Note: Orange-red discoloration of restored teeth is caused by restorative materials like Grossman’s cement and zinc-oxide eugenol cement).

Answer: 2. Grossman’s cement

Question 6. The degree of color saturation is

1. Hue
2. Luma
3. Chroma
4. Luminance

Answer: 3. Chroma

Question 7. The lightness or darkness on a scale of black and white is denoted by

1. Grayscale
2. Value of color
3. Relative luminance scale
4. Saturation of color

Answer: 2. Value of color

Question 8. Alkaptonuria causes

1. Brown discoloration of teeth
2. Yellow discoloration of teeth
3. Brown discoloration of the tongue
4. Yellow discoloration of the tongue
   (Note: Alkaptonuria causes brown discoloration of teeth and is a condition of an inborn error in tyrosine and phenylalanine metabolism).

Answer: 1. Brown discoloration of teeth

Question 9. Gunther’s disease causes

1. Violet-black discoloration of teeth
2. Red-brown discoloration of teeth
3. Yellow-brown discoloration of teeth
4. White-blue discoloration of teeth
   (Note: Error in porphyrin metabolism known as Gunther’s disease will cause a red-brown discoloration of teeth due to porphyrin deposition).

Answer: 2. Red-brown discoloration of teeth

Question 10. Usage of a mouth rinse containing potassium permanganate cause

1. Violet-black discoloration of teeth
2. Red-brown discoloration of teeth
3. Yellow-brown discoloration of teeth
4. Gold-brown discoloration of teeth

Answer: 1. Violet-black discoloration of teeth

Question 11. Stannous fluoride cause

1. Violet-black discoloration of teeth
2. Red-brown discoloration of teeth
3. Yellow-brown discoloration of teeth
4. Gold-brown discoloration of teeth

Answer: 4. Gold-brown discoloration of teeth

Discoloration Of Teeth Highlights

• Teeth become darker with advancing age changes by the secondary dentin deposition, incorporation of extrinsic stains, and gradual wear of enamel. The causes of teeth discoloration may be influenced by underlying systemic diseases and many times give a clue to identify the related disease.
• Environmental factors and drugs also play a role in teeth discoloration. The discoloration may be generalized or may involve a group of teeth.