RELIABILITY OF CREVICULAR FLUID MEASUREMENTS TAKEN IN THE PRESENCE OF SUPRAGINGIVAL PLAQUE

The measurement of gingival crevicular fluid (GCF) is commonly used in clinical studies to quantitate the severity of gingival inflammation. This study examined the influence of the presence of supragingival plaque on GCF readings. Bilateral pairs of maxillary premolars received replicate GCF measurements. One of the teeth was randomly selected to be the test tooth. Supragingival plaque was removed from the test tooth between the first and second GCF measurements. Plaque was not removed from the control tooth. The crevicular fluid was collected on filter paper strips which were placed just subgingivally. The quantity of crevicular fluid was determined with the aid of the Periotron 6000. The mean difference between the first and second GCF measurement for the control teeth was -1.5 +/- 5.7 (+/- SD). This change was not significant (P = 0.21). The mean difference between the first and second GCF measurements for the experimental teeth (-21.3 +/- 16.5) was significant (P less than or equal to .001). The mean difference between the control and the experimental GCF differences were found to be highly significant (P less than or equal to .001). The data indicate that the presence of supragingival plaque can significantly elevate the GCF measurements when determined with the Periotron 6000.