[en] Radiolabelled microspheres and ⁸⁶Rb were used in dogs to measure oral tissue blood flow. The tissues studied were mandibular alveolar and basal bone, oral mucosa, gingiva, lip, tongue and soft tissue of hard palate. A suspension of 6 x 10⁶ cerium-141 labelled microspheres, 15 + - 5 μm in diameter was injected into the left ventricle through an arterial catheter in 9 healthy adult dogs. Cardiovascular stability was assessed during the catheterization and injection of microspheres. Following the microsphere injection, 500 μCi of ⁸⁶Rb was injected intravenously and the animal was killed within 60s. Blood flow measured using ⁸⁶Rb was not significantly different (p > 0.05) from radiolabelled microsphere flow in mandibular basal bone, oral mucosa and gingiva, suggesting that in these oral tissues nutritional or capillary exchange flow is similar to total blood flow. In mandibular alveolar bone, lip, tongue and soft tissue of hard palate, however, ⁸⁶Rb measurements were significantly greater (p < 0.05) than microsphere measurements. The combined use of radiolabelled microsperes and ⁸⁶Rb shows promise for continued studies of blood flow in healthy and pathological oral tissues. (author)