On the origin of gingival crevicular fluid

Relevance. Limited scientific literature exists on the compositional relationship between dentinal fluid and gingival crevicular fluid, as well as their potential interaction. Objective. This study aims to determine the origin of gingival crevicular fluid, compare its composition with that of dentinal fluid and gingival capillary blood, and assess the potential for their interaction.Materials and methods. This study analyzed three biological fluids: dentinal fluid, gingival crevicular fluid, and gingival capillary blood. A total of 35 volunteers participated in the study. The biological fluids were examined using an infrared microspectrometer at the Australian Synchrotron. Additionally, the microrelief of the enamel in extracted intact teeth, removed for orthodontic reasons, was assessed using a JEOL JSM-6380LV scanning electron microscope (Japan).Results. Dentinal and gingival crevicular fluids exhibit a complex composition comparable to that of blood plasma. The findings reveal spectral modes unique to the infrared (IR) spectra of these fluids. Based on this evidence, it is hypothesized that dentinal fluid may infiltrate the gingival sulcus via dentinal and enamel tubules. During this passage, the fluid interacts with hydroxyapatite crystals, resulting in alkalization. Furthermore, the urea concentration in dentinal fluid is 2.3 times higher than in gingival crevicular fluid, which likely contributes to an increased urea concentration in gingival crevicular fluid diffusing from the gingival papilla.Conclusion. Given the newly discovered potential for dentinal and gingival crevicular fluid mixing, we propose refining the terminology by replacing the term "gingival crevicular fluid" with " dentogingival fluid."