Validation of an alternative device for volumetric quantification of crevicular fluid

The volume of crevicular fluid is directly proportional to the degree ofperiodontal inflammation. The Periopaper system, with readings taken using the Periotron, has gained wide acceptance in the literature for measuring this volume. Alternative methods have also been proposed. This study investigated an alternative device for measuring the volume and compared it to the readings taken in Periotron Units (PU). Strips of absorbent paper (PS) of the same size as Periopapers (P) were obtained. Next, previously defined volumes were quantified in PU (R1: P and R2: PS) and also in millimeters (T1: P; T2: PS) using an alternative reading method (ruler and magnifying glass). The mean measurements for each volume were compared (Student's t test) and no difference was detected between them in PU (R1=66.8 and R2=72.5) or in millimeters (T1=2.83 and T2=2.96). The degree of correlation between groups was evaluated using Pearson's coefficient, with an intragroup r of 0.98 (R1xT1; R2xT2; R1xT2). Linear regression coefficients were also calculated, finding R1xT1=23.5; R2xT2=26.5 and R1xT2=23.3. The method's reproducibility was verified using intraclass correlation coefficients, with excellent results--all above 0.96. This being so, it was concluded that it is possible to measure the volume collected in millimeters, with a high degree of reproducibility.