Evaluation of inflammatory periodontal tissue by detecting the hemoglobin released in gingival crevicular fluid during supportive periodontal therapy

The purpose of this study was to longitudinally investigate the hemoglobin (Hb) test in gingival crevicular fluid of periodontitis patients, together with clinical parameters (plaque index: PlI, probing depth: PD, clinical attachment level: CAL, bleeding on probing: BOP, and gingival index: GI) during two-year supportive periodontal therapy (SPT). A total of 191 periodontal sites in 91 patients during the SPT period were clinically and biochemically evaluated three times (first, second, and third examinations) over two years. After the first examination of the clinical and biochemical parameters, periodontal support treatments were administered and then repeated every three months until the third examination. The values of PD, CAL, GI, and Hb decreased from the first examination to the second or third examination. Notably, the percentage reduction of Hb test values was significant. However, only the BOP value tended to increase. The decreases in these clinical and biochemical parameters suggested that the periodontitis was not exacerbated, but rather tended to recover with periodontal treatment. These reductions in PD, CAL, and Hb values from the first examination were clearly more common in the PD ≥ 5 mm group than in the PD ≤ 4 mm group for all test sites. In this study, the highly sensitive Hb test showed that periodontal treatment for two years suppressed the progression of periodontitis. This trend was significant in the deep gingival sulcus (PD ≥ 5 mm) group, suggesting that the Hb test may be a useful quantitative marker to predict recurrence of periodontitis.