摘要:

abstract–Of 5,459 schoolchildren in the town of Umeå, Sweden 26.2 % were regarded as not being in need of orthodontic treatment. As judged according to a four‐grade scale the need was objectively little in 29.4 % of the children, moderate in 33.6 % and strong for 10.8 %. Of the children with objective need of treatment, 21.2 % were not interested in orthodontic treatment. In 939 children referred from the district of Västerbotten the need of treatment was little in only 3.2 %, while strong in 52.3 %, and very strong in 6.3 %. Only 47.8 % of the children were interested in orthodontic trea

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01497.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–In 1,486 schoolchildren with various anomalies, different needs of orthodontic treatment, and treated with different techniques, the following variables were studied: uncompleted orthodontic treatment and reason for cessation of treatment, duration of active treatment, duration of retention period, complete registration period, results of treatment. One to five years after the end of treatment, 300 cases were examined regarding relapse, opinion of treatment, and opinion of the results of treatmen

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01498.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–The uptake and retention of fluoride in surface enamelin vivoafter a single topical application of a neutral 2 % NaF solution was studied on the basis of 2–3 μm thick enamel biopsies from maxillary central incisors in adults and children. The biopsy technique included delimiting of the sampling area by means of abrasive‐resistant, adhesive tape, punched with perforations of known sizes admitting of two biopsies on different places on the same tooth surface. This method made it possible to calculate the depth of each biopsy and to perform the comparative studies with intradental control. The F uptake was estimated by comparing F concentrations in biopsies taken before and 1 week after topical treatment. In teeth of 10‐ to 11‐year‐old children the F concentration increased 259 ± 393 parts/106, which is statistically significant (P0.10). The F concentrations in biopsies taken 1 week and 8 weeks after treatment from teeth in children were almost identical, indicating that the acquired F is firmly fixed in the enamel for 2

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01499.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–The incisal area of the coronal dentin of intact anterior teeth was studied by means of scanning and transmission electron microscopy. The great majority of the tubules were open regardless of age. A variety of fibrous structures with diameters between 50 nm and 0.7 μm were observed within dentinal tubules. The cross‐banding typical of collagen was occasionally discernible in these fibers, but as a rule they had a smooth surface, probably due to masking of structural details by ground substance. Fibers with a tendency to arboresce were interpreted as nerve fibers. Disturbances in the mineralization were observed in a central area of the dentin between the pulp horn and the incisal edge. Especially the development of peritubular dentin was inconsistent. In adult teeth the tubules at this location were occluded by a fine‐textured material. A varying amount of secondary dentin was present in the pulp horn of the teeth at an early age. The first formed tissue had an atubular appearance, whereas in an apical direction the structure became more regular with tubules and intertubular

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01500.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–Attrited dentinal surfaces and subjacent dentin were examined in the scanning electron microscope. In a central area of the exposed surfaces the dentinal tubules were occluded, whereas peripherally most tubules were open. Deposits, apparently dental plaque, were observed on the exposed dentin as uneven, but often continuous, layers covering whole areas of the surfaces. Loss of dentin within delimited areas of the surfaces was observed. The resulting defects could hardly be related to attrition, and it seemed that they were caused by erosive or caries‐like processes. The dentin subjacent to the attrited surfaces was characterized by mineralized inclusions in the dentinal tubules. The inclusions consisted of irregularly rod‐shaped crystals forming a meshwork on the tubule walls. Other crystals were formed as prisms, seemingly rhombohedrons. Crystals which were hexagonal in cross‐section were also seen. The exposure of the dentin also seemed to have influence on the organic content of the tubules. Thus, it appeared that ground substance was removed from the intratubular fibers permitting the observation of cross‐banding typical of collagen at their surfaces. In some tubules the fibers seemed to be covered b

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01501.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–The present investigation was performed to study whether a filtrate from human dental plaque when applied topically to the gingival margin enhances gingivitis. Four‐day‐old plaque was sampled from 20 dental students. The plaque samples were pooled, suspended in NaCl, homogenized, centrifuged and filtered. The capacity of the plaque filtrate to attract neutrophil leukocytes was determined by measuring the number of leukocytes (a) which migrated into wound chambers containing the filtrate and (b) which could be sampled from the gingival crevices of dogs and monkeys after repeated topical application of the filtrate to the gingival margin. Gingivitis was assessed by gingival exudate measurements. The results showed that substances present in human dental plaque are highly chemotactic for neutrophil leukocytes. The filtrate stimulated enhanced emigration of leukocytes into the gingival crevices and enhanced gingival exudation. The observations indicate that a plaque filtrate may enhance vascular and cellular changes similar to those seen in incipient gingi

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01502.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–In order to study the occurrence of accumulations of tissue fluid in the periapical areas of erupting teeth,131I‐fibrinogen was given intracardially to 15 rats, aged 15 or 16 d. The injected fibrinogen was demonstrated autoradiographically in areas of fluid accumulations at molars as well as incisors in several of the animals studied. Weak radioactivity was noted already after 1 h's survival. After 8 or 24 h some effusions produced a very intense blackening of the film. The periapical accumulations of fluid are thus apparently produced by local changes in vascular permeabil

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01503.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–Molar pulp tissue of 42 rats was subjected to cardiac perfusion fixation or to immersion fixation with glutaraldehyde and formaldehyde. The importance of variations in pressure and duration of cardiac perfusion was studied. The results indicated that the perfusion method was superior to immersion fixation. Best preservation of the tissues was obtained when perfusion was performed with 1.7% glutaraldehyde for 10–12 min under a pressure of 130 cmH2O, and leaving the animals for 4 h, without immersion fixation. Also perfusion with formaldehyde resulted in good preservation, provided the solutions were prepared from paraformaldehyde powder. In contrast, solutions made from commercial stock solutions of formaldehyde gave inferior results. For sections stained with hematoxylin‐eosin, perfusion with glutaraldehyde was preferable, while perfusion with formaldehyde showed increased sensitivity in demonstration of dentinal tubules stained with alcian blue at pH 3.6. It is suggested that in future studies on rat pulp tissue, perfusion with glutaraldehyde and formaldehyde should replace immersion fix

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01504.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–The rate ofin vivoturnover andin vitrosynthesis of the glycosaminoglycans (GAGs; acid mucopolysaccharides) of the dental pulp loose connective tissue from rat maxillary incisors has been investigated by isotope methods. The biologic half‐life of35SO4in whole tissue digests was found to be 4.5 d. Of the sulfated GAGs the chondroitin‐4‐sulfate fraction was shown to have a more rapid turnoverin vivothan the chondroitin‐6‐sulfate fraction, 4.1 and 5.2 d, respectively. The fraction containing keratan sulfate and glycoproteins had a biologic half‐life of 6.8 d. Slices of rat incisor pulps were incubatedin vitrowith35SO4and the rate of incorporation into the different GAG fractions was determined. After a lag‐phase of 15 min, this rate was linear with time. The chondroitin‐6‐sulfate fraction showed a more rapid uptake than the chondroitin‐4‐sulfate fraction, and the uptake by keratan sulfate + glycoprotein fraction was much lower. A similarin vitroexperiment using [14C] acetate was performed. Contrary to the sulfate incorporation there was an extended lag‐phase, and the total inc

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01505.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

abstract–The purpose of the present investigation was to induce osteopenia of the alveolar process by feeding dogs a calcium‐deficient, phosphorus‐rich diet, and to determine whether dogs suffering from nutritional secondary hyperparathyroidism (NSH) developed: (1) increased tooth mobility, (2) gingivitis and (3) periodontitis with marginal alveolar bone resorption in plaque‐free areas and in areas where plaque and calculus were allowed to accumulate. The experiments were performed on six, 12‐month‐old Beagle dogs. During an experimental period of 18 months, four dogs (test group) were fed a low calcium, high phosphorus diet of a soft consistency. The controls were fed an adequate but soft diet. The teeth of the right jaws were regularly subjected to thorough cleaning. NSH and osteopenia of the alveolar bone were induced in the test dogs. Osteopenia, however, did not result in an increased tooth mobility or gingivitis in the absence of plaque. In areas where dental deposits were allowed to accumulate, pathologic pockets gradually developed in both test and control animals, but the degree of attachment loss was the same in

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1973.tb01506.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY