The effect of supragingival plaque on crevicular fluid measurements

The purpose of this investigation was to evaluate the influence that supragingival plaque may have on the measurement of crevicular fluid flow (CFF) when it is quantified by the use of a filter paper strip and a Periotron 6000 measuring unit. The study involved 51 human subjects from each of whom an experimental tooth was randomly chosen and a CFF measurement recorded. The quantity of crevicular fluid was collected on filter paper strips placed subgingivally at the entrance to the sulcus for 15 seconds. Any supragingival plaque was then removed, following which a second measurement of the CFF was recorded after 5 minutes. Changes in the CFF were correlated with the plaque index at the experimental site and were shown to be significantly affected by the presence as well as the quantity of supragingival plaque. It was demonstrated that measuring the CFF in the presence of supragingival plaque was not reliable.