An Organ Culture Technique for Maintaining the Pulp Tissue of Intact Human Teeth

Abstract

The size of explants in organ culture is limited by their ability to feed, respire, and excrete by diffusion. The perfusion procedure described in this report is not limited to a particular explant size. The test tissue was the adult human tooth. In order to maintain the pulp tissue of the intact human tooth in organ culture, special precautions were taken to prevent internal necrosis and to allow diffusion of nutrients and waste products. Using aseptic technique, a standard tissue culture medium plus appropriate antibiotics were delivered to a glass manifold housed in an incubator with an atmosphere at 100% humidity containing about 5% CO2. Tubing from the manifold led to small needles which were threaded from the apex of each tooth to the pulp horns. The teeth covered with a layer of saturated gauze rested in modified petri dishes. Adenosine triphosphate concentrations in perfused, nonperfused and immediately extracted teeth were compared to determine the success of the procedure. The mean ATP level in 25 immediately extracted teeth was 0.15 micrograms ATP/mg wet weight. The mean ATP level in 24 teeth successfully perfused for up to 11 days was 0.14 micrograms ATP/mg wet weight, while the ATP level in all non-perfused teeth was 0. 01 micrograms ATP/mg. Eighty-six percent of all teeth were considered successfully perfused. A histologic study on perfused, non-perfused, and immediately fixed teeth revealed good cellular detail, collagen fiber integrity, and normal appearing odontoblasts in many areas of the pulp in teeth perfused for periods up to 14 days. The non-perfused counterparts demonstrated little cellular detail, no odontoblastic layer, and frank necrosis in many areas. In some areas of the pulp of perfused teeth numerous tissue histiocytes could be seen. Using standard tissue culture techniques, explants of pulp perfused for 72 hours showed extensive monolayer outgrowth of fibroblast-like cells. Non-perfused pulp tissue after 72 hours in saline showed no such outgrowth. It is concluded that the perfusion procedure maintained viability of the pulp tissue of intact teeth for extended periods of time