The aim of this study is to observe the mechanism of spreading vasodilatation on human healthy gingiva. Nitric-oxide donor solutions in lower and higher concentration are used to trigger the vasoactivity.

Spatial regulation of gingival microcirculation has not been revealed yet. Although this could be an important mechanism to protect gingiva as it is exposed to mechanical, chemical, thermal etc. irritation during whole life. It is especially important during flap surgery. Laser Speckle Contrast Imaging (LSCI) is novel non-invasive method with high spatio-temporal resolution, therefore it allows us to study remote effect of local vasodilation such as spreading vasodilation in human gingiva.

The vasodilatator nitric-oxide (NO) donor will be used to trigger remote effect on gingiva. NO donor solutions will be applied in 1 mg/ml and 8 mg/ml nitroglycerin concentrations. Solution will be dropped on the gingiva at tooth 12 in a fabricated leakage proof well attached to 2mm above the marginal gingiva. The change on blood flow will be monitor at the test well with surrounding gingival area spanning 3 tooth and at the contralateral side by LSCI.

Inclusion Criteria:

• general health
• minimum 5 mm keratinized gingiva at upper front teeth

Exclusion Criteria:

• pregnancy and breast-feeding
• medication (except contraceptives)
• smoking
• periodontitis
• caries
• insufficient marginal integrity