Usefulness of hemoglobin examination in gingival crevicular fluid during supportive periodontal therapy to diagnose the pre-symptomatic state in periodontal disease

Objectives The absence of bleeding on probing (BOP) is a good predictor of disease stability. This study investigated whether detection of hemoglobin (Hb) in gingival crevicular fluid (GCF) indicates minute signs of periodontal disease, even in BOP (−) cases. Materials and methods GCF was collected from gingival sulci of 152 sound maxillary and mandibular teeth from 76 patients who had entered supportive periodontal therapy (SPT) using the split-mouth design. As clinical parameters, plaque index, GCF amount, gingival index, probing depth (PD), clinical attachment level, BOP, and alveolar bone resorption ratio were then recorded. As biochemical parameters, Hb amount, alkaline phosphatase (ALP) activity, and protein amount in GCF were measured. Periodontal conditions of diseased sites (PD ≥ 4 mm, BOP (+)) and healthy sites (PD ≤ 4 mm, BOP (−)) were further classified into two groups using the Hb cutoff value determined by PD and BOP and analyzed. Results Despite being healthy, ALP activity and protein amount in sulci of the group with Hb level greater than the cutoff value were significantly higher than those in the group with Hb level less than the cutoff value ( P