冠装着後の実験的歯周炎に関する基礎的研究

Abstract

This investigation was carried out to determine whether the cast gold crowns with different locations of the cervical margin cause or are associated with a marked difference in the periodontal conditions. The cervical position of each crown was built up according to the following system: 1) 1mm above, 2) even with and 3) 0.5mm below the gingival margin.Thirty-two teeth in 4 adult dogs were examined. The gingival state and oral hygiene were recorded according to the index systems (Loe, 1967). Pocket depths were calculated. The gingival exudate measurements had been also assessed using the orifice method (Egelberg et al, 1973).The animals were sacrificed at time intervals of 2, 4 and 16 weeks following the placement of the crowns. The blood vessel topography at the dento-gingival junction was studied, after perfusion with a carbon-gelatin mixture prior to the sacrifice (Egelberg, 1966). Bucco-lingual and horizontal serial sections 8 microns thick were made and stained with hematoxylin and eosin. The gingivae adjacent to the crowns were observed microscopically. The morphologic changes are described, based upon the clinical, the cellular inflammatory and the epithelial changes.The results indicate that in areas with crown margin below the gingival crest, more severe gingivitis was registered than in the another areas examined.