
Background and Aims: A high number of patients with periodontitis may have undiagnosed diabetes. It is possible that gingival crevicular blood from routine periodontal probing may be a source of blood for glucose measurements. The purpose of the study was to evaluate whether the blood oozing from the gingival crevice during routine examination could be used for determining glucose levels. Materials and Methods: 100 patients with periodontitis and positive bleeding on probing were chosen. Blood samples of two sites were analyzed using a glucose self-monitoring device. In 50 diabetic and 50 non-diabetic patients, after testing fasting plasma glucose (FPG), glucose levels in gingival crevicular blood (GCB), and capillary fingerstick blood (FSB) samples were analyzed using the same device. Results: The patient’s blood glucose values ranged from 69.5-235.8 mg/dl. The comparison between Gingival Crevicular blood, Fingerstick blood and Intravenous blood showed a very strong correlation with a r value of 0.99(P < 0.001). Interpretations and Conclusions: The data from this study has shown that GCB collected during intraoral examination is an excellent source of blood for glucometric analysis.