When multiple types of root surfaces are exposed, the most severely affected surface should be recorded for that tooth (Katz, page 12). An alternative method of recording would be score each surface (up to 4 per tooth) of teeth with gingival recession.
total number of teeth showing gingival recession =
= (number of teeth showing gingival recession with decay) + (number of teeth showing gingival recession with all root lesions filled) + (number of teeth showing gingival recession with intact surface)
root caries index =
= ((number of teeth showing gingival recession with decay) + (number of teeth showing gingival recession with all root lesions filled)) / (total number of teeth showing gingival recession) * 100
Interpretation:
• minimum score: 0
• maximum score: 100
• The higher the score the more severe the caries.
The index can be modified to report the attack rate for a given tooth or tooth class (premolar, molar, etc.).
There are at least 2 sources for underscoring:
(1) A root caries may occur at the base of a true periodontal pocket without gingival recession.
(2) Gingival swelling may obscure a root caries.
