摘要:

abstract—Quantitative and qualitative examinations of the predominant cultivable microflora of the advanced tissue destruction (pocket) associated with juvenile periodontitis and of control pockets without loss of attachment were carried out by using anaerobic tube culture technique. The microflora from the control sites consisted primarily of streptococci, Gram‐negative rods, and Gram‐positive rods. In contrast, the test pockets had a relatively stable and characteristic microflora, dominated by various Gram‐negative, anaerobic rods. The Gram‐negative rods were divided into main groups, but a satisfactory classification of many of these microorganisms could not be performed with the methods used and the data available. The predominating Gram‐negative rods differed from individual to individual. The role of the Gram‐negative rods in the etiology of juvenile periodontitis is unknown. Some potential pathogenic mechanisms of these microorganisms

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00454.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—A clinical follow‐up study has been carried out in order to study the periodontal health of orthodontically derotated teeth where the supra‐alveolar fibers have been severed by an incision through the bottom of the marginal pocket to the border of the alveolar bone in order to reduce the tendency towards a posttreatment relapse. The material consisted of 30 rotated teeth treated orthodontically in 27 patients between the ages of 9 and 22 years. Following an average retention period of 8.3 months, the supra‐alveolar fibers were severed down to the alveolar bone border. The control material consisted of untreated, banded con‐tralateral teeth in the same jaw. The patients were examined for plaque, gingival health and depth of the marginal pockets. No significant difference in periodontal health could be found on comparison between, on the one hand, teeth treated with fibrotomy and, on the other hand, untrea

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00455.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—Evidence for a possible role played by oral haemophili in the development of dental plaque was sought by studying the occurrence of these bacteria in early dental plaque of smooth surfaces and occlusal fissures in six dental students. The mean number of haemophili per 103anaerobes in early smooth surface plaque (18 h) and fissure plaque (7 d) was 95 and 22 respectively. Examination of 988Haemophilusisolates revealed thatH. parainjluenzaewas the only species in samples of fissure plaque, whereas some samples from smooth surfaces, in addition to the predominating and ubiquitousH. parainfluenzae, yielded growth of the two speciesH. segnisandH. aphrophilus. It is concluded that haemophili are among the primary colonizers of smooth surfaces of teet

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—The adherence of different streptococci to test pieces of glass, human enamel and whale dentin carried in the mouth or immersed in saliva or bacterial suspensions was studied by examining the number and frequency of microorganisms which were selectively desorbed by a standardized washing technique. The results obtained fromin vivoandin vitroexperiments were similar in principle. The proportion of streptococci obtained in the first washing resembled that found in the saliva, but with more vigorous washing the proportion ofS. sanguisincreased while that ofS. salivariusdecreased. This illustrates that different microorganisms can attach to solid surfaces with different strengths. The applicability of the method was tested by treating dentin surfaces with fluoride solutions and by incorporating sucrose in the test solution. The fluoride treatment reduced while the sucrose addition increased the number of streptococci which could be removed from the surface

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00457.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—Thein vivoeffect of formaldehyde on pulp tissue in short‐term studies cannot be established by using routine histologic techniques because the tissue is exposed to a fixativein vivoas well as during the histologic preparation. The pulps of permanent pre‐molars were amputated and zinc oxide with 4% formaldehyde or formocresol was used as wound dressing. The observation periods varied from 1 to 16 d. After extraction the teeth were freeze‐sectioned, freeze‐dried and then incubated for histochemical demonstration of some oxidative and hydrolytic enzymes. A demarcated border between apically stained and cervically nonstained pulp tissue was found in sections incubated for oxidative enzymes. When formocresol, which has a high concentration of formaldehyde, was used, the border was situated closer to the apex. This was also the case when the observation period was increased. The incubation for lactate dehydrogenase gave a high staining intensity. Thus the use of frozen sections in combination with the histochemical method for the demonstration of lactate dehydrogenase appears to be suitable for the study of the penetration of formaldehyde in pulp tissue in short‐t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00458.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—To investigate the mechanism for the toxicity of silicate cement as observed in a cell culture system, the effects of pH and fluoride were tested on human epithelial cells (NCTC 2544). At pH 7.3, fluoride concentrations from 15 to 25 μg/ml (0.79 to 1.3 mM) had a growth inhibitory effect. When pH of the incubation medium was lowered in the range 7.0 to 6.4, an enhanced cytotoxic effect of fluoride was found, and even at 5 to 10 μg/ml growth inhibition occurred. Concomitant with the enhanced cytotoxicity of fluoride at low pH, there was an increased utilization of glucose and formation of lactate. Upon lowering the pH of the incubation medium from 7.4 to 6.7 a twofold increase in the intra‐cellular concentration of fluoride was

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00459.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

abstract—The purpose of the present work was to study (1) the deformation of selected types of cavities in axially loaded human teeth and (2) the possible effect of this deformation on the restorative quality of fillings in the cavities. Recently extracted wet teeth without any visible structural defects were used throughout the study. Standard Class III and large Class III cavities were prepared in maxillary incisors, while Class I, m‐o, m‐o‐d, and Class V cavities were made in maxillary first premolars. For the second part of the study several of the cavities, etched or non‐etched, were filled with restorative resins. Mounted in a measuring microscope the teeth were loaded in a way simulating biting or chewing; cavities with fillings were accepted only when no marginal gaps could be found. The results showed a deformation of empty cavities proportional to the load up to 16 kg, the decrease or increase in diameter being 0.1–1.0 öm/kg, depending on the type of cavity. Loading and unloading of teeth with filled cavities resulted in permanent or transitory gaps. The dimensional instability of cavities in loaded teeth indicates a severe risk of percolation by several restoratives and of marginal fracture of brit

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1976.tb00460.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY