Periodontal treatment of multi rooted teeth.

Abstract This paper describes: (1) a system for classification and treatment of furcation involvements, and (2) a 5-year post-operative evaluation of 100 patients treated for periodontal breakdown in the bi/tri-furction areas. The results of this study demonstrate that it is possible to arrest further destruction within the root furcation area. The successful treatment of the multirooted teeth was probably the consequence of: (1) the quasi total elimination of plaque retention areas from the bi/tri-furcation area, and (2) meticulous oral hygiene by the patients.     

Clinical and microbiological changes associated with an altered subgingival environment induced by periodontal pocket reduction

Abstract The purpose of the present investigation was to study the effect of an altered subgingival environment, induced by changing the local soft tissue morphology, i.e., pocket depth reduction, on the subgingival microbiota and the clinical conditions. 7 patients aged 30–60 years with generalized marginal periodontitis were selected. Patients were instructed in proper oral hygiene and all teeth were cleaned supragingivally. Mucoperiosteal flaps were raised and the bone re-contoured to eliminate angular bony defects. While the control teeth were carefully debrided and thoroughly root planed, no root instrumentation was performed on the test teeth. Calculus deposits visible to the naked eye were only chipped-off with the tip of a sealer. The flaps were apically repositioned and sutured at the level of the bone crest. Clinical parameters showed a similar pattern of response in the test and control sites over a one year observation period post therapy. Probing depths and probing attachment levels were significantly reduced one month after surgery and remained at a lower level. A significant decrease was also noted for total anaerobic viable bacterial counts. The proportion of the Gram-negative anaerobic rods decreased significantly in both groups. P. gingivalis, Fusobacterium sp., C. rectus were detected significantly less often after treatment in both groups. Capnocytophaga and A, odontolyticus, on the other hand, were more frequently isolated after therapy. These findings corroborate the concept that the reduction of selected subgingival microorganisms is the key element for the success of periodontal therapy, rather than the removal of tooth substance and mineralized deposits by root instrumentation.     

An assessment of the risk of developing hyperparathyroidism and thyroid disorders subsequent to neck irradiation in middle-aged women

We investigated the occurrence of thyroid and parathyroid disorders in 100 women (age 66-70 years) irradiated for cervical spondylosis on average 25 years previously and in 100 control women of similar age. Hyperparathyroidism (HPT), proven by operation, was diagnosed in one patient of each group, and three additional cases were diagnosed biochemically among irradiated women. The difference in incidence is not significant. Nor was there any significant difference in incidence of thyroid disorders. No thyroid carcinoma was found in either group. Even if there is a moderate increase of HPT after neck irradiation in middle-aged women the risk is not so great as to warrant organised follow-up.     

Herpes simplex clinical and pathogenetic aspects

Immunologic Research - Primary infection with herpes simplex virus of either type 1 or type 2 occurs frequently, however, recurring disease develops in only a small fraction of the population....     

Healing following reimplantation of teeth subjected to root planing and citric acid treatment

The aim of the present study was to examine the effect of citric acid treatment on periodontal healing around teeth which were extracted, root planed and then reimplanted. Maxillary incisors and mandibular incisors, premolars and molars of 5 monkeys were used. The teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted and immediately reimplanted into their own sockets. In a 2nd group, the teeth were extracted, root planed to a level corresponding to 50-75% of the root length and then reimplanted. In the 3rd group, periodontal breakdown extending to 50-75% of the root length was first induced by placing orthodontic elastic ligatures around the teeth. They were then extracted and root planed and transplanted into the sockets of the contralateral, periodontally healthy teeth which had just been extracted. Half the number of the teeth of groups 2 and 3 were treated with citric acid before reimplantation or transplantation. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. With the exception of a limited coronal regrowth of new cementum in the apical part of the planed portion of a few roots, connective tissue attachment failed to reform on most root surfaces deprived of their periodontal ligament tissue. Healing was most frequently characterized by root resorption and ankylosis. These were the most predominant features of healing both on root surfaces which had been deprived of the ligament tissue by mechanical means or during a course of experimentally-induced periodontal disease, and occurred in citric acid as well as non-citric acid treated roots. The findings imply that the result of healing following tooth reimplantation or transplantation is determined by the type of cells that repopulate the wound area adjacent to the denuded root surface.     

The development of Purkinje fibres and ordinary myocytes in the bovine fetal heart

Summary A comparative ultrastructural study of bovine Purkinje fibres and ordinary myocytes during fetal development has been undertaken. Differences between the two cell types with respect to the intercalated disc, amount of myofibrils, arrangement of mitochondria, amount of glycogen and formation of T-tubules became apparent gradually. In all stages studied an abundance of intermediate filaments was typical for the Purkinje fibres. Myofibrillar M-bands developed at an earlier stage in Purkinje fibres than in ordinary myocytes. Myofilament-polyribosome complexes typical of adult cow Purkinje fibres were not observed in the fetal hearts. Only in late fetal stages were leptofibrils observed in both cell types.We conclude that in the bovine heart Purkinje fibres develop along a different pathway from ordinary myocytes.This study was supported by grants from the Swedish Medical Research Council (12X-3934), the Faculty of Medicine, University of Umeå, and the Expressen Prenatal Fund