## 4 Discussion
The available literature suggests that the increase in GCF volume may be a consequence of subclinical inflammation--microinflammation--occurring in periodontal tissues. The authors hypothesised that occlusal overload caused by bruxism, such as orthodontic forces, may affect the volume and composition of GCF, including the concentration of proinflammatory cytokines. Additionally, a study by [PERSON] et al. [13] showed that as gingival index values and periodontal pocket depth increased, GCF volume increased. Higher volumes were also observed in the direction from incisor teeth (0.12-0.69 \(\mu\)L) to molar teeth (0.24-0.93 \(\mu\)L), whichis anatomically related to the increasing gingival crevice area. In contrast, [PERSON] et al. [40] determined a correlation between GCF volume and gingival index values, finding no such relationship with the depth of periodontal pockets at teeth treated with porcelain veneers. Interestingly, [PERSON] [41] evaluated the effect of chewing khat leaves on GCF secretion among the Yemeni population. An increase in gingival index values and GCF volumes was observed with longer chewing habits, suggesting a higher prevalence of periodontal inflammatory disease. In contrast, plaque index values decreased, which was explained by the ability to self-clean the teeth while chewing these leaves. In other studies, periodontitis markers such as alkaline phosphatase [3] and monocyte chemotactic protein MCP-1 [42] were also determined in GCF. The Periotron can also be used to assess the amount of GCF secreted in the subclinical inflammation of periodontal tissues. [PERSON] et al. [43] compared gingival fluid secretion from the fissures around healthy teeth and those with periodontal disease, and around implants and those with visible peri-implanttis. There was no difference between the volumes of fluid produced at teeth and implants in the same state of periodontal tissue health or disease; however, both resulted in higher volumes of fluid when active inflammation was found. A significant correlation between fluid volume and periodontal pocket depth was only obtained for healthy tissue. Analogously, a study by [PERSON] et al. [44] analysed the relationship between the presence of bacteria (such as _Tamerela forysthia_, _Porhylomonas gingivalis_, _Treponema denticola_, and _Aggregatibacter actinomycetemomitans_) and the volume of fluid secreted from the sulcus around the implants. A significant correlation was obtained between the percentage of bacteria present around the implants and the amount of fluid absorbed by soaked Periopaper strips for 30 s. The authors suggest that the determined volume of secreted fluid from the fissure and its correlation with concentrations of red group bacteria may allow the prediction of the occurrence of peri-implantitis. Researchers are increasingly looking for a relationship between bruxism and periodontal status. As emphasised by [PERSON] et al. [45], the results of previous studies assessing the relationship between bruxism and periodontal disease are contradictory. The mentioned authors in 2021 stated that probable bruxism is related to periodontitis. Among a group of over 500 patients, those who reported grinding and clenching their teeth showed a greater risk of periodontitis. On the other hand, [PERSON] et al. [46] presented in 2019 the results of a cross-sectional study involving over 1000 respondents, reaching opposite conclusions. Patients who declared tooth grinding showed a lower incidence of periodontitis and better clinical manifestation of the disease. Multivariate analysis performed on the above-mentioned subjects suggested that bruxism is significantly associated with a lower risk of periodontitis. It should be emphasised that so far, researchers have only evaluated the clinical manifestation of tissues available in a physical examination, using international periodontal status indicators. The performed studies did not include the collection of GCF samples and did not take into account the biochemical assessment of cytokines.