The assessment of the gingival capillary density with orthogonal spectral polarization (OPS) imaging

In this study we evaluated the inter-observer agreement in the assessment of gingival capillary density using Orthogonal Polarization Spectral Imaging.

In this study gingival capillary density of 100 healthy subjects was determined by 2 independent observers. Agreement was quantified by calculation of the mean differences between the observers and the standard deviation of this difference and the limits of agreement. Reliability was quantified by means of the intraclass correlation coefficient (ICC).

Fifty males and 50 females were included in the study. The mean age for males was 20+/-1.2 years and for females 20+/-1.4. OPS images showed remarkable good quality images of the gingival microcirculation. The interclass correlation between the 2 observers was 0.63 while the interclass correlation for the 6 measurements in observer 1 was 0.95 and 0.94 for observer 2. The mean capillary density for females in observer 1 was 83.69+/-16.4 and 83+/-16.0 in observer 2, versus 60.55+/-12.3 for observer 1 and 60.4+/-12.1 for males. The mean quantitative functional capillary density in male students was 60.48+/-10.7, compared to 83.45+/-13.5 in female students.

OPS imaging enabled for the first time direct in vivo visualization and quantification of human functional gingival capillary density in healthy medical students. The inter-observer agreement was found to be good to fair on the quantification of gingival capillary density between the two independent observers. The intracorrelation coefficient (0.95) was excellent when assessing the reliability of one observer.