摘要:

abstract–Radioactive sodium fluoride (NaF18) and calcium chloride (Ca45Cl2) were injected simultaneously into rats, eight to ten days old. Thirty minutes after injection, the animals were killed by rapid freezing and sectioned sagittally through the level of the teeth. Both F18and Ca45were accumulated in the. superficial zone of the enamel in those areas where matrix was being formed. There was a marked increase in the concentration both of F18and Ca45in the surface of the enamel, where matrix formation was just completed. However, at maturation only Ca45was accumulated in the whole thickness of the enamel, and no F18was found in this area. The results may indicate an association between fluoride and the organic matrix of the developing enamel. The distribution of F18in the enamel was similar to that of tetracycline shortly after injectio

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02024.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–Images formed in the electron microprobe by the current induced in the sample by absorbed electrons illustrated the prism structure and mineral distribution in the enamel of rat incisors. Close to the dentino‐enamel junction a 2 micron wide zone of high electron density was found, bordered on the peripheral side by a 2–3 micron wide zone of low density. Chemical concentration profiles indicated that the content of calcium and phosphorus in this zone was lower than in the underlying d

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02025.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–The fibrinolytic activity of human epithelial cells from the buccal mucosa of 5 females and 3 males was investigated using the fibrin slide technique. It was shown that cells from all layers of the squamous epithelium were fibrinolytically active. No sexual differences were recorded. The results are discussed with special reference to their implications for injury to the epitheliu

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02026.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–Blood group substances A and B were demonstrated in paraffin sections of 6 cases of oral normal epithelium and in 9 cases of atypical (dysplastic) epithelium by use of immunofluorescence and immunoperoxidase staining methods. In normal mucosa the blood group substances appeared on all cells above the basal cell layer. In atypical epithelium, the blood group substances were absent or had a patchy distribution. Correlation was found between the degree of atypia and the absence of blood group substance

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02027.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–One hundred and seventy‐three individuals receiving orthodontic full band treatment in one or both dental arches were examined in order to assess the relationship between caries incidence and oral hygiene during treatment. Thorough instruction in toothbrushing with a horizontal scrub technique was given. Topical application of sodium fluoride was used regularly throughout the experimental period. The average period of treatment was 19 months. Monthly assessments of oral hygiene were performed through partial recordings utilizing the Plaque (PII) and Gingival Index (GI) systems. Smooth surface carious lesions on vestibular and lingual surfaces of banded teeth were assessed according to a proposed Caries Index (CI) at the time of removal of the orthodontic appliances. The results demonstrated a definite correlation between oral health and caries incidence. With increasing mean PII and GI scores, there were concomitant, almost linear increases in mean CI scores. On an average, the girls had lower PII, GI, and CI scores than boys. The correlations between caries incidence and age, duration of treatment, and initial caries experience were not signific

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02028.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–Human dental plaque was collected into iced water. The starting crude enzyme preparation — obtained by sonication and ultracenfrifugation ‐ was tested for its keto acid‐forming activity using different amino acids as substrate. It could be shown that only L‐cystine and L‐cysteine were converted to keto acid by this enzyme preparation. The partly purified enzyme preparation, after BioGel P‐300 gel permeation chromatography, was capable of forming keto acid only from L‐cysteine. The affector studies conducted revealed that cations, such as Al2+, Cr3+, Ca2+, Fe2+, and Cut+, reduced the reaction velocity, and the same could be noted when Na‐cyanide, dithiotreitol, and mercapto‐ethanol were tested. NaF, MgCl2, iodoacetate, Na‐citrate, and Na2‐EDTA exerted no effect on this enzymic reaction. The tested coenzymes, flavin mononucleotide (FMN), flavin dinucleotide (FAD), riboflavin phosphate, and pyridoxal‐5‐phosphate, were innocuous to the keto acid‐forming activity. This study confirms earlier studies that human dental plaque contains an enzyme disulfide reductase, an enzyme known to convert L‐cystine to L‐cysteine, and suggests the existence of a desulfhydrase enzyme in the plaque which converts L‐cysteine to pyruvic

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02029.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–Bacterial lipopolysaccharide endotoxins (LPS) obtained by phenol‐water extraction from oral strains ofBacteroides melaninogenicusandFusobacteriumwere studied in the electron microscope. The LPS particles had a characteristic morphology comparable to that of LPS from other Gram‐negative microorganisms. The LPS appeared as circular structures or discs delimited by single or trilaminar membranes, or as short rods composed of two electron‐dense membranes separated by a fine, less‐dense layer. Teeth with adhering soft and calcified bacterial plaque, which were extracted because of advanced periodontal disease, were obtained and processed for electron microscopy. Close examination of thin sections revealed an abundance of particles in the dental plaque which closely resembled those found in LPS preparations of Gram‐negative oral microorganisms. Circular as well as rod‐like particles were, identified. These particles, which were most frequent in regions containing Gram‐negative bacteria, were distinctly different from the granular, filamentous, and other structures previously reported in the intercellular matrix of the dental plaque. It was concluded that the circular and rod‐like structures described represent free bacterial lipopolysaccharide. LPS particles were found superficially in the plaque as well as in deeper layers and in regions undergoing calcification. In regions containing Gram‐negative bacteria, intercellular mineral deposition often occurred in close association wit

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02030.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–In each of 42 clinically sound premolars scheduled for extraction for orthodontic reasons one vestibular and one lingual cavity were prepared. Four teeth were extracted immediately after cutting of the cavities for control of the effect of the cutting procedure upon the pulp. In the remaining 38 teeth one cavity was selected at random and filled with Silican® without isolation of the cavity walls and the other cavity with Pharmatec® After one hour, one week, one month, and six months the teeth were extracted and examined histologically. In this way intra‐dental control of pulp reactions was possible. After an observation time of one month or less, only slight pulp damage was found under both filling materials. Following the observation period of six months obvious pulp reactions were demonstrated under both filling materials. The pulp damage following insertion of silicate cement therefore does not seem to be the result of the initial acidity of the filling material. Microorganisms were in some cases found on the cavity wall under tre silicate cement fillings. The method used was found to be preferable in comparative studies concerning the harmful effect of filling materials upon the pulp. The findings are disc

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02031.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–The effect of extrusive orthodontic forces on dentin and pulp has been studied histologically on 26 human premolars. Minor reactions related to the circulatory system in the pulp were observed when extrusive forces were opposed by biting forces. Allowing the tooth to extrude freely, it was found that somewhat more pronounced reactions occurred. In addition to circulatory disturbances in the pulp, small epithelial cell islands were found in the apical area. Reparative processes were seen to take place in resorption defects on the root surface shortly after forced remova

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02032.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

abstract–The aim of the present study was to ascertain the fate of a radiographically diagnosed periradicular bone condensation. Clinical and radiographic examinations of 38 teeth were performed at the beginning and end of a follow‐up period of about 4 years. Radiopacity associated with a tooth whose pulp was found to benecrotic organgrenous in most cases normalized after conservative root therapy. In other conditions of the pulp the radiopacity could persist for a long time in spite of appropriate root canal ther

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1971.tb02033.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY