摘要:

Abstract –Teeth and jaws excavated from 25 burial mounds on the island of Bahrain were examined. Dating: 2000 B.C. The number of individuals, buried was estimated from the dentition. An approximate determination of the age for death was attempted. Non‐metric and metric traits of the teeth were observed. The teeth showed Caucasoid but no Mongoloid traits. They were small, worn at an early age, with a great deal of carious lesions, no multiple fractures, only a little calculus and alveoloclasia but frequent enamel hypoplasia, The mandibles, showed fine healing after the widespread antemortem loss of molars, possibly extracted due to the consequence of caries, caused by the consumption of many carbohydra

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01256.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The aim of the present study was to assess the relative importance of the metal and fluoride components in the inhibiting effect on the acidogenicity of plaque exhibited by silver fluoride and copper fluoride. The effect of these salts was therefore compared with that of silver nitrate and copper sulfate. Four subjects with a 3‐day‐old .sucrose induced plaque received topical applications of the test agents. Plaque pH‐measurements, in the presence of sucrose, were performed prior to and at given time intervals after this application. No significant differences were observed in the inhibitory effect of 5 mm solutions of the copper and silver salts These salts were all more effective than stannous fluoride in the first 4 h following application. Sodium fluoride was the least effective. All metals tested were found to be retained in plaque. The inhibitory activity appears to be carried by the cations. Other properties than retention alone may explain the higher effectiveness observed for silver and

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01257.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The effects of tetracycline hydrochloride (TC) on secretory ameloblasts in mandibular incisors and first molars in young rats were investigated. The pathogenesis of the TC‐induced changes was examined in light and electron microscopes 6, 12, 24 and 96 h after a single intraperitoneal injection of a high dose of TC (200 mg TC/kg body wt.) into 4‐d‐old animals. Secretory ameloblasts from non‐injected animals served as controls. Cellular changes were observed in all teeth 6 h after injection. The changes increased with the postinjection period and after 96 h they were so severe that they were considered irreversible. The incipient changes of the ameloblasts comprised altered structure and location of the mitochondria, succeeded by dilated cisternae of endoplasmic reticulum arranged in short curled formations. Later on, distorted Golgi complexes were observed. Secretory granules appeared in various numbers in the Golgi zone and in the Tomes' processes. In severely affected ameloblasts the cell nuclei showed an increased content of chromatin. Autophagic vacuoles and extracellular membrane bound fragments with cellular remnants were frequent, indicating death of some of the ameloblasts. Areas of stippled secretory material were observed along the formative enamel front and in extracellular spaces between the ameloblasts. In the 96‐h group calcified bodies with a varying content of crystals were scattered between the cells. Incisors and the molars displayed similar patterns of structural changes of the secretory ameloblasts; however, the changes developed earlier and became more severe in

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01258.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The aim of this investigation was. to clarify some of the sources of error inherent in coordinatographs and to establish a suitable method of calibrating these instruments. Using a test grid standard measurements were made and parameters for both systematic and random errors calculated. For the instrument employed small but significant errors were recorded for scale error, orthogonal error and X‐axis play. Operator and instrument precision were also determined. It is concluded that regular testing of coordinatographs used in research is necessary if suitable calibration of systematic errors and a control over wear and tear is to be achie

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01259.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –The dissolving effects of seven endodontic solutions on unprepared root canal walls of young intact human premolars were evaluated with the scanning electron microscope. After incubation at 37°C in distilled water or isotonic saline for 10 min the predentinal surfaces showed no changes as compared with untreated controls. The demineralizers Decal® and Largal Ultra® had little effect on the organic tissues but caused some decalcification where mineralized dentin was exposed. Nelex® caused concentration‐dependent coagulation of the residual pulp tissue, making typical ring structures on the surfaces. Sodium hypochlorite at 2.5% and 5.0% dissolved most of the predentin, exposing the globular appearance of the mineralizing front. Salvizol® produced small globules on otherwise intact surfaces. Dissolution of both the organic and inorganic tissue of the root canal wall would require the combined use of two of the solutions

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01260.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –X‐ray diffraction analyses were carried out from pooled samples of old subgingival calculus. Also the concentrations of Ca, Mg, Zn, Sr, Pb, Fe and Cu from these samples were determined by means of atomic absorption spectrophotometry. The comparison of the samples containing almost the same Zn concentration and two different concentrations of Mg (9 mg/g and 16 mg/g) showed an increase of 2. 0. 10 and 220 whitlockite reflections with an increasing Mg concentration. The increase of Mg concentration shifted whitlockite reflections suggesting a contraction of a‐axis. The increase of Zn concentration showed an increase of 2. 0. 10 and 220 reflections indicating the fitness of Zn into the laitice of whitlockite. No changes of a‐axis were detectable. When comparing all diffractograms and the results obtained from chemical analyses, the presence of Zn‐Mg‐whitlockite pro

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01261.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Elements present in minor or trace quantities in various toothpastes available in Scandinavia have been quantitatively assayed by means of emission spectrography and neutron activation analysis. The elements antimony, arsenic, mercury or selenium were observed at levels less than 2 parts/106. Boron, gallium, iron, magnesium, manganese and titanium occurred at levels between 0.001 and 1 %. Cadmium, copper, lead, nickel and tin could not be identified. The detection limit for these elements amounted to 10 parts/106. The amounts of any of these elements which could be transferred to the body after swallowing toothpaste during brushing, have been compared with daily intake of similar elements through food and drinks, and found to be small compared to the diet intake except in the case of titanium. The intake of titanium from toothpaste could exceed the diet intake five time

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01262.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Arthrography was performed in 166 temporomandibular joints with known disorders. The results reflected the pathology expected in each disorder. Clicking and locking were characterized by an increased inferior synovial cavity. The superior cavity was either normal or with irregularity of the articular space. In degenerative diseases, the most frequent finding was perforation of the disc. Rheumatoid arthritis was characterized by reduced extent and irregular outline of the synovial cavities. A late effect from contusion of the temporomandibular joint was a slight reduction in the extent of the synovial cavity. Late effects from intracapsular fracture of the mandibular condyle were considerable irregularity of the articular space and perforation of the disc. As a rule, the arthrographs were highly characteristic, and it seems possible to distinguish between the current disorders by means of arthrography. The arthrographs of 15 intact joints are described. The features of unsuccessful arthrography based on 32 instances of extrasynovial injection are describe

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01263.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Lipopolysaccharides (LPS) isolated from oral strains of Veillonella, Fusobacterium and Bacteroides stimulated the release of45Ca from prelabeled fetal rat bones in culture. There was a typical dose‐response relationship berween the quantities of released45Ca and LPS used for stimulation. Bacteroides‐LPS proved to be the less active inducer of45Ca release. LPS had no stimulating effect on the release of45Ca from devitalized bone. The stimulated45Ca release was paralleled by an increase in the culture midium of hydroxyproline and lactate. This, together with the findings of numerous osteoclasts in stained hisological specimens of the experimental bones, indicates that LPS stimulated the osteoclasts to bone resoption. Heparin, which did not directly induce45Ca release, potentiated the bone resorption stimulating capability of LPS. The lipid A and the polysaccharide portion of Fusobacterium LPS also stimulated bone resorption and, remarkably, the polysaccharide portion showed the greatest activity. This may explain the mode of action of LPS lacking a typical lipid A. It is suggested that stimulation of osteoclasts by LPS may result from activation of complement by lipid A or its polysaccharide po

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01264.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract –Twenty rats were exposed to dust particles of chromium‐cobalt alloy abrasives produced in dental material handling. The exposure was carried out in chambers for periods up to 107 days at concentrations of particulate matter of about 10‐50 mg/m3. The content of chromium and cobalt in autopsy specimens of lung, liver, kidney and trachea was measured with nuclear techniques. The alloy particles were found to be markedly accumulated in lung tissue. Increased levels of chromium and cobalt were also observed in the trachea. In addition, a moderate increase of cobalt in liver and kidney was demonstrated. The lungs of six exposed rats were examined microscopically. The main part of the dust particles was observed within macrophages. Only a minor fraction of particles were seen in the bronchial lumen close to the epithelial surface. The majority of dust‐filled macrophages were located in groups within the bronchial wall or in the interstitium close to the terminal broncheoli. No fibrosis, dysplasia or tumor formation occurred. No acute adverse effects in the lungs were o

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1980.tb01265.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY