Why is a plaque score not used to assess risk?
All patients accumulate plaque but a minority develop periodontitis. The threshold of plaque accumulation required to cause damage in one patient is different to that in another. Plaque scores measure quantity and not quality of plaque and are very difficult to standardize for all dentists and hygienists. They do not measure sub gingival bacteria, provide no information about pathogenicity, and a patient can invalidate it with atypically good oral hygiene just prior to the evaluation.
