[Examination of periodontal disease with gingival crevicular fluid. Correlation between capacitance and clinical findings].

An intimate relationship between the inflammatory state of the gingiva and the amount of gingival crevicular fluid (GCF) is well known. For the measurement of the volume of GCF, filter paper has been used in the past. In the present study, an electrostatic capacity measuring apparatus with sensor that is insertable into gingival sulcus was fabricated. Capacitance of GCF was measured in patients with periodontitis and the following results were obtained. 1. The measuring apparatus was controlled by a personal computer to obtain the data every 0.1 second. As the GI increased at the site of measurement, higher values were obtained, with longer persistence of the trend of increase in the measured value. 2. In view of the stability of the measured values, the amount of GCF appeared to be best expressed as the value obtained after 10 seconds. 3. The correlation between the capacitance and the clinical findings was evaluated at 500 sites. The correlation was the highest in GI followed by P1I, GBI and PD, suggesting the utility of this method in the detection of initial gingival inflammation.