Intrinsic Stains

Pre-eruptive Causes

These are incorporated into the deeper layers of enamel and dentin during odontogenesis and alter the development and appearance of the enamel and dentin

.Alkaptonuria: Dark brown pigmentation of primary teeth is commonly seen in alkaptonuria. It is an autosomal recessive disorder resulting into complete oxidation of tyrosine and phenylalanine causing increased level of homogentisic acid.

Hematological disorders

• Erythroblastosis fetalis: It is a blood disorder of neonates due to Rh incompatibility. In this, stain does not involve teeth or portions of teeth developing after cessation of hemolysis shortly after birth. Stain is usually green, brown or bluish in color.

• Congenital porphyria: It is an inborn error of por- phyrin metabolism, characterized by overproduction of uroporphyrin. Deciduous and permanent teeth may show a red or brownish discoloration. Under ultraviolet light, teeth show red fluorescence.

• Sickle cell anemia: It is inherited blood dyscrasia characterized by increased hemolysis of red blood cells. In sickle cell anemia infrequently the stains of the teeth are similar to those of erythroblastosis fetalis, but discoloration is more severe, involves both dentitions and does not resolve with time.

Amelogenesis imperfecta: It comprises of a group of conditions, that demonstrate developmental alteration in the structure of the enamel in the absence of a systemic disorders. Amelogenesis imperfecta (AI) has been classified mainly into hypoplastic, hypocalcified and hypomaturation type.

Fluorosis: In fluorosis, staining is due to excessive fluoride uptake during development of enamel. Excess fluoride induces a metabolic change in ameloblast and the resultant enamel has a defective matrix and an irregular, hypomineralized structure 

• Vitamin D deficiency results in characteristic white patch hypoplasia in teeth.
• Vitamin C deficiency together with vitamin A deficiency during formative periods of dentition resulting in pitting type appearance of teeth.
• Childhood illnesses during odontogenesis, such as exanthematous fevers, malnutrition, metabolic disorder, etc. also affect teeth.

0. Dentinogenesis imperfecta : It is an autosomal dominant development disturbance of the dentin which occurs along or in conjunction with amelogenesis imperfecta. Color of teeth in dentinogenesis imperfecta (DI) varies from gray to brownish violet to yellowish brown with a characteristic usual translucent or opalescent hue.
1. Tetracycline and minocycline: Unsightly dis- coloration of both dentitions results from excessive intake of tetracycline and minocycline during the development of teeth. Chelation of tetracycline molecule with calcium in hydroxyapatite crystals forms tetracycline orthophosphate which is responsible for discolored teeth.

Posteruptive Causes

• Pulpal changes: Pulp necrosis usually results from bacterial, mechanical or chemical irritation to pulp. In this disintegration products enter dentinal tubules and cause discoloration.
• Trauma: Accidental injury to tooth can cause pulpal and enamel degenerative changes that may alter color of teeth.Pulpal hemorrhage leads to grayish discoloration and nonvital appearance. Injury causes hemorrhage which results in lysis of RBCs and liberation of iron sulfide which enter dentinal tubules and discolor surrounding tooth.
• Dentin hypercalcification: Dentin hypercalcification results when there are excessive irregular elements in the pulp chamber and canal walls. It causes decrease in translucency and yellowish or yellow brown discoloration of the teeth.
• Dental caries: In general, teeth present a discolored appearance around areas of bacterial stagnation and leaking restorations.
• Restorative materials and dental procedures: Discoloration can also result from the use of endodontic sealers and restorative materials.
• Aging: Color changes in teeth with age result from surface and subsurface changes. Age related discoloration are because of:– Enamel changes: Both thinning and texture changes occur in enamel.

– Dentin deposition: Secondary and tertiary dentin deposits, pulp stones cause changes in the color of teeth.

• Functional and parafunctional changes: Tooth wear may give a darker appearance to the teeth because of loss of tooth surface and exposure of dentin which is yellower and is susceptible to color changes by absorption of oral fluids and deposition of reparative dentin.

Extrinsic Stains

Daily Acquired Stains

Plaque: Pellicle and plaque on tooth surface gives rise to yellowish appearance of teeth.

Food and beverages: Tea, coffee, red wine, curry and colas if taken in excess cause discoloration.

Tobacco use results in brown to black appearance of teeth.

Poor oral hygiene manifests as:

• –  Green stain
• –  Brown stain
• –  Orange stain.

Swimmer’s calculus:
– It is yellow to dark brown stain present on facial andlingual surfaces of anterior teeth. It occurs due toprolonged exposure to pool water.

Gingival hemorrhage.

Chemicals

• Chlorhexidine stain: The stains produced by use of chlorhexidine are yellowish brown to brownish in nature.

Metallic stains: These are caused by metals and metallic salts introduced into oral cavity in metal containing dust inhaled by industry workers or through orally administered drugs.

Stains caused by different metals

• Copper dust—green stain
• Iron dust—brown stain
• Mercury—greenish black stain • Nickel—green stain
• Silver—black stain.

Reference- Nisha garg textbook of endosontics and Anil Ghom textbook of oral medicine