摘要:

Abstract –Five totally impacted third molars were studied in the transmission electron microscope for the presence of nervous structures in the dentin before eruption. In contradiction to earlier studies available, nervous structures were found in the predentin and the dentin of the impacted third molars in different parts of the crown and also in the predentin of the roo

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01286.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –The dental features in a hitherto unknown type of renal tubular acidosis (capillary blood pH 7.07–7.15) of proximal type are reported. The patient presented agenesis of three second premolars, delayed development and eruption of permanent teeth, delayed shedding of the primary dentition and severe enamel hypoplasia of the permanent teeth, Apart from exceptionally thin enamel, histologic, fluorescent and polarization microscopic and microradiographic investigation of three primary teeth did not reveal unusual findings. The changes are most probably due to a generalized, acidosis‐induced defect in several highly differentiated ectodermal ti

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01287.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –The timing of tooth formation in 251 children, affected with isolated cleft palate without syndromes or other concomitant visceral anomalies (CP), was evaluated from orthopantomograms. The age range was 6–12 yr. The formation of the permanent teeth was delayed approximately 0.7 yr in CP children compared with the data on the non‐cleft reference group. There were no differences in sex distribution between the CP group and the non‐cleft reference group and between the CP subgroups. No significant differences in tooth formation could be detected between the subgroups; with and without positive family history of clefts, with and without conical elevation of the lower lip, and between the subgroups of submucous, partial and complete cleft of the palate. The presence of hypodontia promoted the delay significantly and the delay increased with increasing number of missing teeth per child. In the older age group of 9–12 yr, the delay was significantly longer (1.1 yr) than in the younger age group of 6–9 yr (0.6 yr). The present findings of tooth formation support the hypothesis that the genetic component in the multifactorial situation does not act directly in producing the malformation itself, but indirectly, through a reduction in buffering. Furthermore, at least some of the sporadic cases have a partly genet

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01288.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –Two multi‐step extraction procedures were used to isolate matrix proteins from fetal bovine enamel. Using SDS‐PAGE and gel isoelectric focusing it was concluded that extraction procedures influence the number of protein bands in the gel, their pI, apparent molecular weight and staining inte

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01289.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –Tetracyclines can react with enamel and dentin to form relatively insoluble fluorescent compounds. The purpose of this study was to evaluate the possible antimicrobial effect of these reaction products on various microorganisms associated with human dental plaque and periodontal disease. Slabs of native dentin and enamel as well as demineralized dentin were immersed in aqueous solutions of tetracycline HC1, oxytetracycline HC1 and doxycycline HC1 for periods of 1 h or 24 h. Unimpregnated enamel and dentin slabs sterilized by gamma irradiation and specimens impregnated with phenoxymethylpenicillin calcium were used as controls. Test and control specimens were placed on agar plates seeded with B. cereus, C. ochraceus, S. sanguis, F. nucleatum, B. melaninogenicus or A. viscosus and were subsequently incubated aerobically or anaerobically at 37°C. With the exception of enamel impregnated for 1 h in a 0.01 mg/ml tetracycline solution, all test specimens caused growth inhibition zones, varying in size according to concentration of the drug, immersion period and bacterial species. The results indicate that tetracyclines react with enamel and dentin to form slightly soluble compounds with a pronounced antibacterial effect. In comparison, the antimicrobial effect of dentin treated with penicillin was sma

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01290.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –According to the recommendations of the National Board of Health in Finland fluoride tablets should be used daily from the age of 6 months to 15 yr in fluoride deficient areas. Topical fluorides are recommended in addition to systemic fluorides. The aim of this study was to analyze the use of fluoride tablets and topical fluorides by Finnish adolescents. Teenagers (n= 4705) representing Finnish youth aged 12, 14, 16 and 18 yr were sent mail questionnaires in February 1981. The response rate was 88%. The proportion of daily fluoride tablet users was 12% among 12‐yr‐old girls, 3% among 14‐yr‐old girls and among boys 10% and 4%, respectively. Fluoride rinses at home were used daily by only 1%. During the most recent school term, 34% had several times, and 8% once, participated in classroom fluoride rinsing. In the same period 14% had used fluoride gel several times, and 10% once. Thus despite dental health education, fluoride tablets and rinses are used very rarely at home by Finnish teenagers. The recommendations of the National Board of Health are far removed from the behavior of adolescents. Use of fluoride tablets and topical fluorides do not seem to be a practical alternative to drinking‐water fluoridation, because of the low level of

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01291.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –Flow rate, pH and lactobacillus and yeast counts of paraffin‐stimulated whole saliva were analyzed in an adult population of 463 medicated persons. Of the very large number of drugs only a few groups were found to decrease salivation to such an extent that they can be considered to cause dental harm. Persons using neuroleptics, tricyclic antidepressants or antihypertensives were nevertheless found to produce stimulated saliva at rates significantly lower than unmedicated persons. Age had no influence on the flow rate, but postmenopausal age seems to predispose medicated women to a decrease in salivary flow. Higher microbial counts were found in the medicated

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01292.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –The aim of this work was to study the influence of bacterial cell concentrations and inorganic anions on lysis of Streptococcus mutans BHT by human salivary lysozyme (HSL). HSL was partly purified from saliva by ion exchange chromatography. The bacteria were grown in a synthetic medium containing3H‐thymidine to monitor DNA release. The experiments demonstrated that release3H‐thymidine was dependent on the bacterial cell concentration and an apparent Km‐value corresponding to approximately 2.9 × 108cells/ml was calculated. The influence of I−, Br−, Cl−, F−, HCO3−and SCN−on bacteriolysis was studied. All anions tested were slightly inhibitory on the action of HSL. The inhibition varied from 7 to 76% depending on the ion and ionic strength. The order of addition of HSL and sodium chloride caused different lytic responses. This was reflected by the amount of HSL adso

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01293.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –The disintegration in water of various unset glass ionomer cements, a polycarboxylate and a zinc phosphate cement was measured gravimetrically after exposure of the cements to a constant water jet. The test gave reproducible results with significant variations between the various types and brands of cements. For zinc phosphate and polycarboxylate cements, no weight loss was observed in the period from 4 to 8 min after commencement of mixing. All the glass ionomer cements showed a significant loss of weight at 4 min and a somewhat reduced weight loss at 6 min after start of mixing. Two cements, a filling and a luting material, showed reduced weight when exposed to a water jet even 8 min after start of mixing. The early erosion as recorded in the present study conforms with the setting of the glass ionomer cement

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01294.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract –Cylindric dentin cavities ranging from 2 to 6 mm in diameter were treated with different dentin adhesives: Clearfil, Gluma, NPG‐GMA + PMDM, Scotchbond or Superbond before filling with Silux. The maximal contraction gap was measured 10 min after curing and compared with result from cavities where an adhesive was omitted. The effectiveness in reducing contraction gaps increased in the following order: Clearfil, Scotchbond, NPG‐GMA+PMDM, Superbond and

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1984.tb01295.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY