[Quantitative evaluation of permeability of root canalicular system]

The purpose of this study was to evaluate the rate of permeability of the canalicular system of the root (apical and central portion) using albumin labelled with 131J-radioisotope. Freshly extracted central maxillar incisors were divided in three groups: I 10 specimens were used to quantity the rate of the tracer penetration through the apical foramen and apical ramification; II 10 specimens were used for the measurement of central root portion permeability for the same tracer; III. This group was the control group; it consisted of 5 samples which were tested to the sealing ability of the used sticky-wax. The results showed: 1). Through an apical foramen and ramification 56% of radiolabelled albumin penetrated into an external saline eluent; 2). When albumin was used as an eluent another amount of 6.5% of 131J-albumin was released; 3) About 38% of total albumin tracer was irreversibly bound to the components of root dentine and cement; 4). Through the central portion of the root canalicular system 50% of radiolabelled albumin penetrated from the root canal; 5). Penetration of large molecules (m.w. 67000), like bacterial endotoxins and protein metabolic products, is absolutely possible and penetration occurs primarily through a system of apical ramification and pulpo-periodontal communication as well as through a canalicular pattern of root dentine and cement.