Background. Several studies in the last decades have focused on finding a precise method for the diagnosis of periodontal disease in its early stages. Aim. To evaluate from current scientific literature the most common and precise method for gingival crevicular fluid (GCF) sample collection, biomarker analytical methods, and the variability of biomarker quantification, even when using the same analytical technique. Methodology. An electronic search was conducted on in vivo studies that presented clinical data on techniques used for GCF collection and biomarker analysis. Results. The results showed that 71.1%, 24.7%, and 4.1% of the studies used absorption, microcapillary, and washing techniques, respectively, in their gingival crevicular fluid collection. 73.1% of the researchers analyzed their samples by using enzyme-linked immunosorbent assay (ELISA). 22.6%, 19.5%, and 18.5% of the researchers included interleukin-1 beta (IL-1β), matrix metalloproteinase-8 (MMP-8), and tumor necrosis factor-alpha (TNF-α), respectively, in their studies as biomarkers for periodontal disease. Conclusion. IL-1β can be considered among the most common biomarkers that give precise results and can be used as an indicator of periodontal disease progression. Furthermore, paper strips are the most convenient and accurate method for gingival crevicular fluid collection, while enzyme-linked immunosorbent assay can be considered the most conventional method for the diagnosis of biofluids.

Objectives:The aim of this study was to determine the levels of LL-37 and subgingival periodontal pathogens in the periodontal health and disease among three ethnic groups in Malaysia.Methods: Gingival crevicular fluid (GCF) and subgingival plaque samples from 28 healthy subjects (H), 30 patients with gingivitis (G) and 30 patients with chronic periodontitis (CP) were collected. The LL-37 levels were quantified by the enzyme-linked immunosorbent assay (ELISA) while the subgingival periodontal pathogens were identified using polymerase chain reaction (PCR). Result:The LL-37 levels were significantly higher in the CP group than other groups. The detectability of LL-37 in CP group was 100%, while in H and G groups was 78.5% and 93.3% respectively. Red complex species populations in CP group are higher than in other groups. The LL-37 levels in GCF were positively correlated with red complex and A. actinomycetemcomitans species in the subgingival plaque. Moreover, there is a positive correlation between the LL-37 levels and periodontal pathogens which play major role in the initiation and progression of chronic periodontitis. Conclusion:LL-37 in GCF may be considered as relevant biomarker for chronic periodontitis. Furthermore, red complex species count can be useful in the differentiation between the different stages of periodontal disease.