Objective: To test the feasibility of using gingival crevice blood (GCB) collected during routine periodontal examination to estimate blood glucose levels using a novel and very sensitive self-monitoring device (FreeStyle).
Subjects and methods: Forty-six patients (20 male, 26 female; age range 12-56 years, mean age 36 +/- 11 years) seeking dental treatment took part in the study. Three and 4 patients reported diabetes mellitus type 1 and 2, respectively; 24 had gingivitis, of which 22 were moderate or advanced periodontitis. Periodontal probing depth (PD) and clinical attachment loss was measured at 6 sites of every tooth present, and bleeding on probing (BOP) was recorded. A site with profuse BOP was chosen for glucose determination. Measurements in GCB were compared with those of conventional capillary fingerstick blood (CFB).
Results: Sufficiently large GCB volumes provided glucometer readings in 32 cases (range 1.17-10.00 mmol/l). The CFB readings ranged between 1.39 and 11.50 mmol/l. If low amounts of crevice blood prohibited a glucometer reading, significantly lower mean numbers of sites with BOP (26 vs. 67, p <0.001) and elevated PD > or =4 mm (2 vs. 21, p <0.05) were seen. Agreement between the two measurements was low, the mean difference was -1.22, and limits of agreement (1.96 times the standard deviation of differences) were +/-2.89 mmol/l.
Conclusion: The present study failed to provide any evidence for the usefulness of GCB for testing blood glucose during routine periodontal examination.