a. General. Dental stains are simply defined as pigmented deposits either on
the tooth surface or within the tooth structure. Dental stains are of particular importance
to the preventive dentistry specialist and the dental officer since stains may be an
indicator of poor oral hygiene and destructive oral habits. Dental stains may also
indicate the presence of a more serious general health problem. Much time and effort is
spent removing stains from patients' teeth, primarily because they can become serious
esthetic problems. Dental stains are further classified by their source and location.
Classification by source is listed as either exogenous (stain that is produced outside the
tooth) or endogenous (stain that is produced inside the tooth). An example of an
exogenous stain is tar from tobacco smoke. An example of endogenous stain is a
brown stain from too much fluoride (fluorosis) occurring inside the enamel. Stains
classified by location are either extrinsic (external) or intrinsic (internal). Extrinsic stains
are caused by food, chemicals, or color-producing (chromogenic) microorganisms.
Intrinsic stains are caused by pulpal disease, tetracycline therapy, enamel hypoplasia,
porphyria, or erythroblastosis fetalis.
b. Extrinsic Stains.
(1) Brown stain. Brown stain is usually caused by a bacteria-free, pigmented-
acquired pellicle. This stain is found on the buccal surfaces of maxillary molars and on
the lingual surfaces of mandibular incisors.
(2) Tobacco stain. Tobacco stain is generally dark brown or black in color
due to coal tar combustion products. This stain is very difficult to remove and is the
most common stain encountered in any dental practice.
(3) Green stain. Green stain is caused by color-producing (chromogenic)
bacteria or fungi. This stain is most common in children, since it occurs primarily in the
remains of the enamel cuticle of newly erupted teeth. This stain is also seen most
commonly on the facial surfaces of the maxillary anterior teeth.
(4) Black stain. Black stain is also caused by chromogenic bacteria and
occurs as a narrow band just above the gingival margin. It is seen in both adults and
children and is easily removed.
c. Intrinsic Stains.
(1) Pulpal disease. This black to reddish stain is caused by the leakage of
blood components (heme) into the dentinal tubules. This stain is usually removed after
endodontic therapy to the tooth by the use of oxidizing agents (bleaching).