摘要:

AbstractThis pilot study was undertaken to correlate clinical and MRI diagnoses in seven symptomatic TMJ dysfunction patients and to account, if possible, for the clinical improvement in the signs and symptoms after the use of a maxillary stabilizing splint. The symptomatic TMJs were evaluated by means of MRI prior to splint insertion. Sagittal open/closed, and coronal closed images were obtained with a 0.3 T Fonar MR Scanner. A follow‐up MRI was taken after three months of splint therapy for the purposes of a comparative study.All subjects responded positively even at the early phase of splint treatment. By the end of the three month period, six subjects experienced full remission of pain in the TMJ and associated masticatory muscles with one subject experiencing only partial remission following therapy. Baseline MRI study revealed that only three subjects had anterior disc displacement while the other four subjects had normal disc/condyle relationships and morphology. In the follow‐up MRI study, there were no signs of recapture of the three anteriorly displaced discs despite there being evidence of improved jaw movement and remission of pain symptoms.The use of MRI in this preliminary study indicates that some but not all TMJ pain dysfunction syndromes are caused by internal derangements of the joint. A larger MRI study using the same clinical parameters is indicated for future resea

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03119.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThis preliminary study was undertaken to investigate the effects of Nd:YAG and Ho:YAG lasers on enamel and dentine of extracted teeth. The Ho:YAG laser (spot size 250 μm, energy density 4160 J/cm2) produced a cleaner puncture in dentine with less melting of the surrounding tissue than did the Nd:YAG laser (spot size 20 μm), energy density 50 000 J/cm2), which produced considerable melting and recrystallization of dentine and was more difficult to control. It was possible to cut enamel and dentine with both lasers, but considerable melted and recrystallized enamel was produced. From the limited observations of this study it appears that the Ho:YAG laser is more suitable for cutting both enamel and dentine than the Nd:YAG laser. More work needs to be done to ascertain the effect on enamel and dentine of modification of the parameters of both laser

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03120.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to investigate the use of 4 per cent sodium hypochlorite and 15 per cent EDTAC, either alone or in conjunction, as irrigants during hand instrumentation and ultrasonic irrigation of the root canal. Thirty‐six extracted human teeth, each with a single, straight root 21–25 mm long were hand‐instrumented through a clinical access cavity to file size 40. One millilitre of the test irrigant was used after each instrument size. Canal debridement was completed with an intermittent flush irrigation technique with one or both of the test irrigants activated by ultrasound at a medium effective power output. The specimens were sectioned longitudinally, viewed in a scanning electron microscope and scored for the presence or absence of debris and smear layer at levels less than 1 mm, 5 mm, and 10 mm from the apical seat. Under the conditions of this experiment the most effective regime was irrigation with 1 mL EDTAC after each instrument size, followed by two 30 second exposures to ultrasound + EDTAC then four 30 second exposures to ultrasound + 4 per cent sodium hypochlorite. The specimens in this group were free from retained pulp tissue and superficial smear layer, had the lowest debris scores at the<1 mm and 5 mm levels, and the lowest total debris score. All of the techniques tested produced smear‐free canals at the 10 m

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03121.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractCandida albicanshas been shown to vary in its phenotypic expression with the progression of human immunodeficiency virus (HIV) infection. This study was designed to investigate whether in Category IV HIV infected patients (CDC, Atlanta, USA) these phenotypic changes were related to changes in the genetic strain of the organism. Isolates ofC. albicanswere obtained from 45 patients with HIV infection during the progression of their disease as determined by percentage T4 lymphocyte count. Isolates were strain differentiated using two methods. In 67 per cent of the patients a single strain ofC. albicans, as determined by the DNA analysis, was isolated from each individual over the experimental period. The phenotypic expression of the genetically identical strains isolated from each patient varied considerably over the experimental period with the morphotype 754 being predominant. These results showed that the genotype ofC. albicansisolated persisted in the majority of HIV infected individuals, but that the phenotypical expression of this strain changed. A finding in this study was that 18 strains ofC. albicanshad DNA which did not hybridize to the probe used. These strains were analysed for the presence of two otherC. albicansspecific DNA segments using PCR. The probe 27A hybridizing strains yielded PCR products which differed from the non‐hybridizing strains. Five of these genetically atypicalC. albicansstrains and 98 of theC. albicansstrains were then analysed for purported virulence factors. The genetically atypicalC. albicansstrains, by comparison with typicalC. albicansstrains, produced greater amounts of extracellular proteinase (p = 0.038, Student'sttest), adhered to a greater degree to buccal epithelial cells (p = 0.018, Student's nest) and were less susceptible to the anti‐fungal drug flucytosine (p = 0.0003, Mann‐Whitney test). Analysis of these strains with other common antifungal drugs showed no statistically significant variation in susceptibility. The results of this study indicated that these genetically atypicalC. albicansstrains possess increased virulence by comparison with typicalC. albicansst

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03122.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractLittle information has been published on the knowledge and perceived competence of dentists in resuscitation or the occurrence of resuscitation emergencies in dental practice. Further, no such surveys have been done in Australia. A postal survey was therefore devised and the names of 350 dentists were randomly selected from the Australian Dental Association national membership registry. The response rate was approximately 45 per cent and the main results included: just under half of the respondents felt they were competent in basic resuscitation at the time of graduation, that is, in expired air resuscitation (EAR) and cardiopulmonary resuscitation (CPR); just less than two‐thirds had undertaken resuscitation training since graduation; about three‐quarters felt they would be able to perform EAR and almost two‐thirds felt they would be able to perform CPR; almost 90 per cent gained a satisfactory score in a Resuscitation Quiz included in the survey; and just over 5 per cent had had to resuscitate a pa

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03123.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractObserved variation in facial morphology results from the influences of both genetic and environmental factors. To investigate the role of genetic influences on variation in facial profile, lateral photographs of 23 male and 19 female monozygous (MZ), and 15 male and 22 female dizygous (DZ) twin pairs were selected from the records of the South Australian Twin Study. Soft tissue landmarks and facial profiles were identified, traced and digitized. Linear and angular measures defined by the landmarks were calculated and a series of Fourier functions derived to describe the facial profiles. These Fourier amplitudes were interpreted in terms of the specific regions which they represented.Correlations within MZ pairs were consistently higher than within DZ pairs for both the facial dimensions and the Fourier amplitudes, providing evidence of significant genetic contribution to facial convexity, facial height and facial depth. Variability in nose and lip morphology appeared to be under stronger environmental influence.

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03124.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractFibroblasts were isolated from human dental pulps of healthy third molars from 49 donors of ages ranging from 17 to 68. Significant variability was noted in the success of obtaining primary cultures from these pulps. Variability between the various cultures was also observed in the reliability of maintaining subcultures of the primary cultures as well as recovery from frozen stocks of established cell lines. Of the original 49 explant cultures studied, only three survived long‐term passage and freezing. In addition to difficulties and variability in establishing cell lines, the human pulp fibroblasts also showed great variability in proliferative activity which could not be accounted for by donor age, source, or passage number. These findings highlight significant difficulties in establishing reliable human pulp fibroblast cultures and the need for great care in interpreting anyin vitrodat

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03125.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe response of the periodontal ligament to orthodontic extrusion of the incisor of a beagle was examined with light microscope and scanning electron microscope techniques. The ligament morphology was slightly altered by the procedure but was essentially normal. Teeth that were extruded and retained for 12 weeks exhibited partial relapse. Where a full thickness mucogingival flap was raised and immediately replaced in lieu of retention, continued extrusion was observed. Root resorption was observed at the interproximal region of the cervical third in three out of five specimens. The resorption had been repaired with cellular cementum.

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03126.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractMembers of theStreptococcus sanguisgroup (SSG) andStreptococcus millerigroup (SMG) were screened for their ability to produce glycosidase, arylamidase (peptidase), protease, dextranase and glycosyltransferase activities. Species within each group produced unique patterns of activity. The most commonly produced glycosidases were β‐D‐glucosidase, β‐D‐ galactosidase, N‐acetyl‐β‐D‐glucosaminidase and N‐acetyl‐β‐D‐galactosaminidase and the least commonly produced glycosidase activity was β‐fucosidase withStreptococcus intermedius(SMG) being the only species capable of producing the activity. For arylamidase activity, the most commonly produced type was lysine‐arylamidase. Glycosidase and arylamidase activities were localized to particular sub‐cellular fractions. α‐galactosidase was found only in culture supernatant fluids whereas N‐acetyl‐β‐D‐glucosaminidase was found in all fractions; the culture supernatant, cell wall, cell membrane and cytoplasm. No arylamidase activity was seen in culture supernatants. Phe‐arg‐arylamidase was found only in cytoplasmic fractions whereas val‐pro‐arg‐arylamidase was found in cell walls, cell membranes and cytoplasmic fraction. Protease activity was measured as the degradation of bovine serum albumin (BSA) and casein. Casein was degraded by a number of strains whereas no species/strains were able to degrade BSA.Streptococcus intermedius, Streptococcus constellates(SMG),Streptococcus mitiorandStreptococcus defectivus(SSG) were the only species that produced hyaluronidase and no species produced chondroitin sulphatase.The groups were also examined for their abilities to produce glycosyltransferase and dextranase.Strep. sanguis, Streptococcus gordonii, Streptococcus mitisandStreptococcus oralisproduced glucosyltransferase and, with the exception of the latter species, fructosyl‐transferase. No species within the SMG was capable of producing either glycosyltransferase. No species within the SSG or SMG was able to produce dextranase activity. The ability of species to produce different types of enzymes was related to their taxonomy, allowing the differentiation of several new taxonom

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03127.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractT cell induced differentiation of B cells has been shown to be dependent on the CD2/LFA‐3 and LFA‐1/ICAM‐1 pathways. Flow cytometric analysis was used to examine these adhesion molecules on T and B cells extracted from gingival tissues before and after stimulation with the putative periodon‐topathic bacteria,Porphyromonas gingivalisandFusobacterium nucleatum.Adhesion molecule expression on peripheral blood cells from healthy adults was used as a control. Approximately 50 per cent of B cells extracted from gingival tissues expressed LFA‐3 and ICAM‐1 compared with 30 per cent positive peripheral blood B cells. Around 50 per cent of gingival T cells expressed CD2 relative to 76 per cent positive peripheral blood T cells. However, 40–50 per cent of both gingival and peripheral blood T cells expressed LFA‐1. There was no difference in the expression of adhesion molecules on T and B cells extracted from health/marginal gingivitis or adult periodontitis lesions. After stimulation of gingival cellsin vitro, the per cent CD2 positive T cells and LFA‐3 and ICAM‐1 positive B cells remained relatively stable over the six‐day culture period, althoughP. gingivalisandF. nucleatumappeared to induce an increase in the percentage of gingival T cells expressing LFA‐1. In contrast to the gingival lymphocytes, stimulation of peripheral blood cells resulted in an increase in the per cent CD2 positive T cells, LFA‐3 and ICAM‐1 positive B cells, with a decrease in LFA‐1 positive T cells. The results therefore demonstrated that gingival T and B cells express adhesion moleculesin vivo.Stimulation of these cells with periodontopathy bacteria failed to increase expression, suggesting not only that these cells are already activatedin vivo, but also that their phenotype is consistent with cell‐cell contact occurring in the gingival tissues. Whether or not this cell‐cell contact is also antigen

ISSN:0045-0421    

DOI:10.1111/j.1834-7819.1995.tb03128.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY