Color analysis of graft and recipient site after free gingival graft surgery using polarized digital photograph

The aim of this cross-sectional study was to evaluate the color characteristics of free gingival graft (FGG) and the adjacent gingiva using polarized filtered digital photographs in cases where more than six months have elapsed since the procedure, , and to assess the potential influence of clinical and sociodemographic factors on gingival color . Fifty cases involving FGG procedures covering one or two lower anterior incisors were included in the study. Clinical parameters including probing pocket depth, bleeding on probing, clinical attachment level, width of keratinized gingiva, and thickness of keratinized gingiva were recorded. Standardized color reference disks were placed on the labial surfaces of the treated teeth, and both filtered and unfiltered photographs were taken. The images were saved in JPEG format and analyzed using the CIELab color system in Adobe Photoshop. A p-value of less than 0.05 was considered statistically significant. A correlation was found between the L, a and b color values of the FGG and gingival thickness. The findings indicated that when tissue thickness exceeded 2.5 mm, the L* (lightness) value was higher and the a* (redness) value was lower compared to cases with tissue thickness ≤2.5 mm (p < 0.05). The greatest perceptible color difference (ΔE) was detected between the coronal and apical regions of the graft. In filtered photographs, the color difference between the FGG and the adjacent gingival tissue was 11.18 units, significantly surpassing the threshold for aesthetic acceptability.. The study demonstrated that the L, a and b color characteristics of the gingiva can very significantly when measured digitally, and gingival thickness is a key factor influencing gingival color following FGG. These findings highlighted the importance of developing standardized tools for evaluating aesthetics not only at the tooth level, but also at the gingival and mucosal levels. Keywords: CIELab, cross-polarized filter, ΔE ,digital color analysis, free gingival graft