[The clinico-pathological studies on the influence of immediate root canal filling after formalin guaiacol was applied on the extirpated pulp surface].

The method of immediate root canal filling following vital pulp extirpation involves many problems to be solved clinically. Therefore, the present study was performed to increase the clinical usefulness by applying formalin medicine in the root canal before immediate root canal filling after vital pulp extirpation. Group 1 (the group of applying formalin tricresol or formalin guaiacol on the intentionally exposed pulp tissue) Group 2 (pulp extirpation). This study is based upon 95 human permanent teeth with noninfected pulps in patients ranging in age from 16 to 43 years. Under local anesthesia the experimental teeth were isolated with cotton rolls. The pulp was intentionally exposed during the preparation of the Ingle's cavity with diamond instruments mounted on a high speed air turbine. The cavity and exposed pulp surface were cleaned with Neo-cleaner (10% Hypochlorite) and oxydol, and then dried using an absorbent material. One of the experimental medicines, which had been saturated into phi 2mm cotton pellet, was applied on the exposed pulp tissue. The cavity was filled with gutta-percha and amalgam. Under local anesthesia, the pulp was intentionally exposed in the same way as mentioned above. After removal of pulp tissue, root canals were cleaned with oxydol. Root canals were filled with Calvital (CV) in 15 cases. Following insertion of sterilized paper point soaked in the solution of formalin guaiacol (FG) or formalin tricresol (FC) for 5 minutes, root canal filling with Calvital was carried out in 20 cases. The experimental teeth were clinically observed at various intervals, and then extracted. After fixation in 10% formalin solution, the teeth were decalcified using nitric acid and embedded in celloidin. The serial sections were stained with hematoxylin and eosin and observed histopathologically. Group 1. 1. Kinds of clinical discomfort observed in this investigation were as follows. FG: Spontaneous pain (25.0%), Percussion discomfort (5.0%). FC: Spontaneous pain (35.0%), Percussion discomfort (35.0%). 2. Clinical results were as follows. FG: 14 cases (70.0%) out of 20 were evaluated as good, 6 cases (30.0%) as fairly good, and none as bad. FC: 11 cases (55.0%) out of 20 were evaluated as good, 9 cases (45.0%) as fairly good, and none as bad. 3. Histopathological changes observed in this investigation were as follows. 1) Hyperemia, 2) Hemorrhage, 3) Round cell infiltration, 4) Suppurative inflammation, 5) Coagulation necrosis, 6) Atrophy, 7) Cicatrization. Group 2. 1. Kinds of clinical discomfort observed in this investigation were as follows. CV: Spontaneous pain (20.0%), Percussion discomfort (20.0%). FG: Spontaneous pain (30.0%), Percussion discomfort (15.0%). FC: Spontaneous pain (30.0%), Percussion discomfort (30.0%). 2. Clinical results were as follows.