A self-contained, indwelling continuous flow apparatus designed for intra-oral research

Abstract

A self-contained, continuous flow apparatus weighing 12.5 g was developed. The apparatus had two chambers, experimental and control, each with a capacity of 0.7 ml of solution which was delivered at a constant rate (1 ml in 5.7 hr). The apparatus was strapped to the back of an adult rat with an adjustable harness and small polyethylene tubing was placed subcutaneously from the apparatus to the mouth. A 30-gauge needle was attached to the tubing and pierced the interdental papillary area between the maxillary first and second molars. The experimental chamber was filled with a solution of hyalurondiase and collagenase and the control chamber was filled with distilled water. Twelve and twenty-four hour experimental runs were conducted. Marked inflammation and sloughing were observed grossly on the experimental side. The control side exhibited only slight redness. In another group of animals, to which the test and control solutions were applied intermittently (every hour) there was little difference between control and experimental areas. It was concluded that the apparatus would function in vivo, that a continuous flow rate was essential for producing the observed changes, and that any cross contamination occurring was not sufficient to obscure differences between control and experimental areas. This report suggests that the perfusion apparatus may be most usefully adapted to a variety of experimental situations, including the study of periodontal disease and caries.