The Tooth Surface Index of Fluorosis (TSIF) measures the aesthetic features resultant from exposure to fluoride in the drinking water. The index was developed at the National Institute of Dental Research.



(1) Tooth surfaces are not dried before the examination.

(2) A separate score is given to each facial and lingual surface of anterior teeth and to each buccal, occlusal, and lingual surface of the posterior teeth. A maximum of 72 surfaces are examined.

Appearance of Enamel

TSIF Score

no evidence of flurosis


parchment white fluorosis involves < 33% of visible tooth surface

includes "snowcapping" of teeth


parchment white fluorosis involves >= 33% but < 66% of visible tooth surface


parchment white fluorosis involves >= 66% of the visible tooth surface


staining of enamel in conjunction with any of the findings listed above


discrete pitting of enamel surface without staining of intact enamel


discrete pitting of enamel surface, AND

staining of intact enamel


confluent pitting of the enamel surface

large areas of enamel may be missing, with altered tooth anatomy

dark brown stain is usually present




• "Snowcapping" refers to parchment white fluorosis confined to the incisal edges of the anterior teeth and cusp tips of the posterior teeth.

• Staining is an area of definite discoloration that may range from light to very dark brown.

• A pit is a definite physical defect in the enamel surface with a rough floor that is surrounded by a wall of intact enamel. The pitted area is often stained or differs in color from the surrounding enamel.



(1) There is no questionable category.

(2) Scores 1-3 depend on the amount of visible surface area involved. This may be affected by whether the fluoride intake has been continuous or intermittent.

(3) Distinction between discrete and confluent pitting makes the index more sensitive to higher degrees of fluorosis than the Dean scale of fluorosis.



• Scoring tends to be clearer than for earlier indices and less subjective.

• The large number of surfaces scored tends to make the index more sensitive than indices using fewer measures.

• Interobserver variability tends to occur in scoring the anterior and posterior teeth. The lingual surfaces are more difficult to examine than the buccal surfaces. The kappa value for all teeth tends to be significantly lower than the kappa value shown for only the anterior teeth.


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