The purpose of this study was to evaluate the microcirculation in subjects with moderate gingivitis, periodontitis, and healthy gingiva. Sixty adult volunteers with clinically healthy gingiva, moderate gingivitis, and periodontitis (20 subjects each) participated in this study. The ages of the research samples ranged from 20 to 35 years. Gingival health was evaluated by using the qualitative plaque index, gingival index, gingival bleeding index, tooth mobility, probing pocket depth, clinical attachment level, and laser Doppler flowmetry (LDF) on six maxillary anterior teeth. LDF data were recorded at the facial aspect of free gingivae, interdental gingivae, attached gingivae, and alveolar mucosae on six maxillary anterior teeth, utilizing an acrylic stent to stabilize the probe. This technique was then modified to circumvent contamination by saliva and gingival exudate. When results were compared at similar sites in each patient within a trial group, there were significant differences in blood flow measurements at all the sites examined between moderate gingivitis and periodontitis when compared with measurements in healthy human gingiva. However, blood flow measurements within the same group showed significant differences at every site, at P< 0.01.