摘要:

The purpose of the investigation was to present an experimental model for a comparative histological evaluation of the effect on gingiva using two different types of bristle material at tooth brushing. Fifteen dogs constituted the material. Two different teeth or groups of teeth were selected on each dog. One tooths was brushed with a nylon brush. The diameter of the bristles was approximately 0.25 mm. The other tooth was brushed with a polytene brush. The diameter of the bristles vary between 0.7 mm at the base of the bristle to 0.25 mm in the near end of the bristle. Manual brushing during 10—60 seconds was carried out in 7 dogs and the other eight dogs were brushed with a mechanical device for 10—30 seconds. A histological evaluation of the relative degree of tissue damages based upon a grading of these damages in terms of a 0—3 point scale was carried out by two independent observers. Wilcoxon's matched-pair signed rank test was applied for a statistical analysis of the result of the histological examination. The conclusion was that the two different types of brushes most likely cause different damages on the gingival tissue and that the polytene brush appeared to cause less tissue damage than the nylon brush.

ISSN:0001-6357    

DOI:10.3109/00016357509026352

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

A study on the composition of the resin component of the several brands of composite resin has not been published so far. It was the purpose of the present work to fill out this gap in our knowledge of this important group of restorative materials by analyzing the monomers of the materials as delivered by the manufacturers. 24 brands of restorative resins were investigated by means of a Nuclear Magnetic Resonance spectrometer at 90 MHz. Spectra were taken of deuterated chloroform solutions of the organic part of the filling materials and compared with spectra of pure monomers that were conceivable constituents of the investigated brands. It was found that the BIS-GMA containing brands all contain at least one other monomer, most often TEDMA, in varying concentrations. The brands with MMA as main component in most cases also contain other monomers.

ISSN:0001-6357    

DOI:10.3109/00016357509026353

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

The aim of the study was to assess the oral health of a group of children, and to compare the findings with the results from an investigation performed 4 years earlier in children of the same age and living in the same area. The material consisted of 149 randomly selected 8-year-old children. The study included examination of caries and the state of the gingival conditions, enamel hypoplasia and opacities, supragingival calculus and extrinsic stains. Determinations were also made of the rate of secretion, pH and buffer effect of stimulated saliva. Socio-economic data and anamnestic dental data were noted. The investigation showed a decrease in caries frequency in the primary teeth, but not in the permanent teeth, during the four-year-period. As in the former investigation, regression analyses showed a negative correlation between the level of education of the parents and caries indices, and that the variation of the gingival indices could be explained by socio-economic factors. In addition, a negative correlation was found between the caries index for primary teeth and the rate of secretion of the saliva and the presence of supragingival calculus.

ISSN:0001-6357    

DOI:10.3109/00016357509026354

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

The inorganic pyrophosphatase (PPiase) activity was determined by a colorimetric method in the odontoblasts and the parts of the enamel organ related to enamel matrix formation and enamel maturation. The effects on PPi hydrolysis by EDTA, R 8231, urea and heat treatment were found to be almost identical to those reported for nonspecific alkaline phosphatase (APase) in the same tissues. The Mg2r activation curve for PPiasc was also similar. Like those of APase, these characteristics of PPiase activity were identical in the three locations studied. It is suggested that the close similarity in the properties of PPiase and APase is due to activity of the same enzyme, a concept which is in agreement with recent biochemical and histochemical studies of calcification.

ISSN:0001-6357    

DOI:10.3109/00016357509026355

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

Secondary caries associated with silver amalgam fillings is characterized by outer lesions and cavity wall lesions. In this study the content of minerals and the penetration of elements from the amalgam into such lesions were analyzed. In sections of 11 teeth including cases of natural secondary caries and experimentalin vitroandin vivolesions around silver amalgam fillings the distribution of Ca, P. Mg, Zn, Sn, Cu, Ag and Hg was studied by means of two-dimensional X-ray images, hear scans and point analyses. Dentine wall lesions where microradiographs had shown increased radiopacity relative to intact tissue, exhibited considerably reduced Ca and P values. The outer portion of the radiopaque areas contained 5—8 % Zn and Sn, decreasing to<0.1 % at a varying distance up to 130Üm from the cavity wall. Hg was not detected, nor was Ag, except in one specimen. The increased radiopacity of this zone as observed on microradiographs is, therefore, obviously caused by the presence of Zn and Sn. Zn and Sn had also penetrated into the moderately demineralized enamel lesions, but the concentrations were generally lower than those observed in the dentine.

ISSN:0001-6357    

DOI:10.3109/00016357509026356

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

The enzymeβ-glucuronidase (E.C. 3.2.1.31.) has been studied in developing teeth and bone of Sprague-Dawley rats and Macaque monkeys(Macaca Irus)by means of histochemistry using naphthol-AS-B1-β-D-glucuronide as substrate and hexazotized pararosanilin as coupling reagent. Sinceβ-glucuronidase is sensitive to fixatives a freeze-sectioning technique has been used which made it possible to section highly mineralizcd tissues without previous fixation and decalcification. In the bone enzyme activity was found in osteoclasts and osteoblasts.β-glucuronidase activity was found in teeth of both species in odontoblasts, ameloblasts, stratum intermedium, inner and outer enamel epithelium. When enamel matrix formation was completed as indicated by the reduction of ameloblast length the enzyme activity of the ameloblasts increased.

ISSN:0001-6357    

DOI:10.3109/00016357509026357

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

Pairs of posterior bitewing radiographs of forty children 13—15 years of age at the third and fourth examinations of three-year clinical trials were assessed by one examiner for primary caries. Duplicate assessments were carried out in independent sessions, recording simultaneously absence/presence of caries and caries degree, and in the same way for three different diagnostic levels recording only absence/presence of caries.Caries diagnostic inconsistency rate (D.I.R.) in per cent was always lower than 34 and usually below 20; a finding which is in agreement with previously published results. No preference could be expressed for any particular diagnostic level on the basis of the primary caries scores, but recording only relatively advanced lesions tended to give most favourable results for DFS increment scores.The recording of both absence/presence of caries and caries degree simultaneously had a small, but not consistently adverse effect on the D.I.R. and reliability coefficient.As there was no marked difference in examiner error associated with two of the demarcation lines used for recording of caries degree, i.e. half way through enamel and the A.D.J., the scoring codes described here may be suitable for studies of radiographic caries progression.

ISSN:0001-6357    

DOI:10.3109/00016357509026358

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor