bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy, cleaning ability and safety of different devices for gutta‐percha removal in root canal retreatment
Authors: HÜLSMANN M. , STOTZ S. 
Published: November 2003

SummaryThe purpose of this study was to evaluate the efficacy, cleaning ability and safety of five different devices and techniques to remove gutta‐percha root canal fillings. One hundred and twenty extracted single‐rooted anterior and premolar teeth were enlarged to ISO size 35 and obturated with laterally condensed gutta‐percha using AH 26 as the sealer. Removal of gutta‐percha was performed with the following devices and techniques: (a) Gates–Glidden and Hedstrom files, (b) only Hedstrom files, (c) Hedstrom files and chloroform, (d) the Endotec and Hedstrom files, and (e) the XGP drill and Hedstrom files. The following data were recorded: time taken to reach the desired working length, time required for the removal of the gutta‐percha, and the amount of material extruded apically. The teeth were split longitudinally and photographed. Cleanliness of the root canal walls was scored using the projected slides with a total magnification of approximately 70 X. The fastest technique to reach the working length was using the XGP drill (e), followed by the Gates–Glidden drills (a), Hedstrom files and chloroform (c), and the Endotec device (d).The use of Hedstrom files (b) without any additional support proved to be most time‐consuming. Differences were Statistically significant (U‐test, P > 0.05) between the rotary devices and the manual techniques. Time for complete removal of gutta‐percha was again shortest with the XGP drills (e), followed by the Gates‐Glidden burs (a), the Endotec device (d), Hedstrom files with chloroform (c), and Hedstrom files alone (b). The XGP burs and the Gates‐Glidden drills worked significantly faster than the other techniques. The amount of debris and filling material extruded apically in most cases did not exceed 0.1 mg. No significant differences could be detected between the groups (U‐test, P > 0.05). Root canal cleanliness proved best following the use of Hedstrom files without additional support (b) and the Gates‐Glidden drills (a), followed by Hedstrom files in combination with chloroform (c), the XGP‐gutta‐percha remover (e), and the Endotec device (d). When using the XGP two instrument fractures occurred in the apical parts of the root canals preventing further instrumentation to the apical foramen. When using the Gates‐Glidden burs four instrument fractures occurred, but all fragments could be removed with forceps immediately. The results suggest that the XGP gutta‐percha remover and the Gates‐Glidden drills are efficient and time saving devices to remove gutta‐percha but include a certain risk of instrument breakage and may leave some filling material inside the root canal. The best root canal cleanliness was achieved with Hedstrom files alone which, on the other hand, were shown to be the most time‐consuming.
TNF‐α release in monocytes after exposure to calcium hydroxide treated Escherichia coli LPS
Authors: BARTHEL C. R. , LEVIN L. G. , REISNER H. M. , TROPE M. 
Published: November 2003

SummaryLipopolysaccharide (LPS), a cell wall component of Gram negative anaerobic bacteria, has been implicated in the pathogenesis of periapical disease resulting from infected root canals. Calcium hydroxide [Ca(OH)2] has been shown to be an effective medicament in such infections, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of Ca(OH)2 may also be the result of direct inactivation of LPS. The aim of this study was to investigate whether the toxic potential of an Escherichia coli LPS could be reduced or eliminated by Ca(OH)2. Four concentrations of E. coli LPS ranging from 1–1000 ng/ml sterile water were incubated in duplicate either with 25 mg Ca(OH)2 or sterile water alone. Controls consisted of Ca(OH)2 without LPS or sterile water only. Monocytes were collected from peripheral blood by centriiuging through a gradient and plated to a specific density. Adherent monocytes were incubated for 4 days at 37° with 5% CO2 in M199 medium with 10% autologous serum. The different LPS solutions were added to the wells on day 5. After 4 h the supernatants were collected and quantitatively assayed for TNF‐α using a commercial ELISA kit. Statistical analysis was performed with ANOVA. Results indicated that Ca(OH)2 is able to eliminate the ability of an E. coli LPS to stimulate TNF‐α production in peripheral blood monocytes (P<0.0001).
Shaping ability of NT Engine and McXim rotary nickel–titanium instruments in simulated root canals.Part 2
Authors: THOMPSON S. A. , DUMMER P. M. H. 
Published: November 2003

SummaryThe aim of this laboratory‐based study was to determine the shaping ability of NT Engine and McXim nickel‐titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with NT Engine and McXim instruments, using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Pre‐ and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre‐ and postoperative views were superimposed to highlight the amount and position of material removed during preparation. No zips, elbows, perforations or danger zones were created during preparation. Forty‐two per cent of canals had ledges on the outer aspect of the curve, the majority of which (16 out of 17) occurred in canals with short acute curves. There were significant differences (P<0.001) between canal shapes in terms of the incidence of ledges. There were highly significant differences (P<0.001) between the canal shapes in total canal width at specific points along the canal length and in the amount of resin removed from the inner and outer aspects of the curve. The direction of canal transportation at the endpoint of preparation was most frequently towards the outer aspect of the curve, especially in canals with 40° curves. At the beginning of the curve, transportation in the majority of canals was towards the inner aspect of the curve. Mean absolute transportation was less than 0.03 mm throughout the curve and towards the endpoint, with significant differences between canal shapes occurring at the apex (P<0.05) and at the beginning of the curve (P<0.001). Under the conditions of this study, NT Engine and McXim rotary nickel–titanium instruments created no aberrations other than ledges and produced only minimal transportation. The overall shape of canals was good.
Undergraduate endodontic teaching in the United Kingdom: an update
Authors: QUALTROUGH A. J. E. , DUMMER P. M. H. 
Published: November 2003

SummaryAnecdotal evidence and scientific surveys suggest that the quality of root canal treatment within the General Dental Services is often less than ideal. Six years ago, it was reported that endodontic teaching in the United Kingdom was given a low priority and that the time devoted to the laboratory practice of root canal treatment should be increased. In the following year, the European Endodontic Society (ESE) published guidelines for the teaching of Endodontology and made recommendations as to what should be included in the undergraduate curriculum. Shortly afterwards, the ESE published quality guidelines for endodontic treatment. The aim of this project was to determine the current pattern of undergraduate endodontic teaching within the dental schools of the UK. Data were gathered by questionnaire from all 14 undergraduate dental schools and supplemented with further detailed enquiries where necessary. The results were compared with that reported following an identical survey carried out previously. Although the ESE curriculum guidelines for endodontic teaching provide an overall framework for teaching, the results of this study confirmed that a number of topics were either not included or were covered only briefly. However, the average time devoted to the preclinical instruction of root canal treatment in the first clinical year had increased from 14 to 24 h, with additional time provided in subsequent years by the majority of schools. In most instances, staff teaching endodontology in the UK have no specialist training.
The acrosome reaction response assay: a new way to identify patients in whom pentoxifylline would improve the human follicular fluid‐induced acrosome reaction
Authors: BRIGGILER C. I. MARÍN , CALVO L. , LANCUBA S. , DELCOURT S. , GOGORZA S. , TRICÁRICO J. M. , TESTA R. , CAMEO M. A. S. 
Published: November 2003

The effect of pentoxifylline on the spontaneous and follicular fluid (hFF)‐induced acrosome reaction (AR) was studied in an attempt to identify those patients who would benefit from the use of pentoxifylline as an AR‐stimulating agent. Pentoxifylline (1 mg/ml) produced no significant increase over spontaneous AR at any of the time points studied (60 min: 6.2% ± 2.0 spontaneous AR vs 7.4% ± 2.0 pentoxifylline AR; 120 min: 7.1% ± 1.6 spontaneous vs 9.0% ± 2.5 pentoxifylline; 180 min: 7.0% ± 1.8 spontaneous vs 10.9% ± 4.0 pentoxifylline, n = 6). On the other hand, hFF produced a significant increase in AR (6.9% spontaneous AR vs 11.2% hFF AR, p < 0.001, n = 39) and this effect was enhanced by pre‐incubation with pentoxifylline (15.0% pentoxifylline + hFF AR vs 11.2% hFF AR, p < 0.001). There were no differences in percentage AR induced by hFF or pentoxifylline + hFF between patients with normal (n = 16) and abnormal (n = 25) semen samples. Individual analysis of the effects of hFF and pentoxifylline + hFF on AR showed great variability between patients and enabled us to classify them into four categories: inducible‐responder (15%), non‐inducible‐responder (23%), inducible‐non‐responder (41%) and non‐inducible‐non‐responder (21%). An induction index (II) (induction produced by hFF divided by spontaneous AR) and a response index (RI) (induction produced by pentoxifylline + hFF divided by hFF) were calculated for each sample. Patients previously classified as inducible exhibited an II > 0.30 and patients previously classified as responders showed an RI > 0.26. There was no correlation between II and RI values (Spearman, r = −0.185, p = 1).Our results show that pentoxifylline is an enhancer of the induced AR only in some patients. We propose an `AR response assay' to identify responder patients and thus enable rational use of this drug.
Ultrastructural study of the effect of cyclophosphamide on the growth area of incisor teeth of DBA/2 and C57BL/6 mice
Authors: ANTON ELSA 
Published: November 2003

The effect of a single dose of 300 mg/kg of cyclophosphamide (CY) on the ultrastructure of the basal area of lower incisor teeth was investigated in two strains of mice (DBA/2 and C57BL/6) which are very differently affected by the delayed toxicity of CY. As in the rat, CY produced necrosis in the primitive mesenchymal cells and preodontoblasts of the pulp. Moreover, important changes were noticed in the associated layers of the enamel organ (presumptive stratum intermedium cells and stellate reticulum); thus, most of the cells displayed degenerative changes including extensive vacuolization, cytoplasm sequestration and variable nuclear alterations ranging from relative integrity to complete disorganization. In contrast, non‐dividing columnar odontoblasts and ameloblasts were not affected by the drug. The alterations appeared as early as 21 hours after CY and progressed in the following 2 and 3 days. Normality of the formative tooth end was regained 7 days after CY. These results indicate that in addition to the effect on the pulp, CY produces severe cytopathological changes in the cells of the stratum intermedium and stellate reticulum of the enamel organ.The different sensitivity of DBA/2 and C57BL/6 mice to the delayed toxicity of CY does not seem to be related to its effect on odontogenesis since both strains showed the same response to CY in this respect.
In vivo growth and differentiation potential of tracheal basal cells of rabbits in vitamin A deficiency
Authors: INAYAMA YOSHIAKI , KITAMURA HITOSHI , SHIBAGAKI TOKUHIKO , USUDA YASUHIRO , ITO TAKAAKI , NAKATANI YUKIO , KANISAWA MASAYOSHI 
Published: November 2003

The growth and differentiation potential of rabbit tracheal basal cells were investigated in vitamin A deficient mice. Denuded rat tracheal grafts were xenotransplanted into nude mice made vitamin A deficient by feeding them retinol‐free pellets from mid‐gestation. Rabbit tracheal epithelial cells harvested enzymatically or cells derived from a basal‐cell‐rich fraction obtained by elutriation (purity 93.3%) had previously been inoculated into the grafts (n = 8, each). The grafts were implanted into the vitamin A deficient or control mice aged about 10 weeks. Four weeks later, the grafts were retrieved for histological examination.The graft epithelium established by either basal cells or un‐fractionated cells in vitamin A deficient hosts (groups 1 and 2, respectively) was atrophic, whereas grafts repopulated with both cell types in the controls had pseudostratified columnar epithelium. Group 1 and 2 grafts both showed squamous metaplasia; 10 metaplastic foci in 32 tracheal rings in group 1 (P < 0.02 or 0.002, compared with values for group 2 or controls, respectively), and 2 foci in 35 rings in group 2 (no statistical difference compared with controls).In conclusion, during vitamin A deficiency, rabbit tracheal epithelial cells, including the progeny of highly‐purified basal cells, lost their potential for establishing a mucociliary epithelium and rather appeared to undergo squamous metaplasia.
Profiles of the response to noradrenaline in the whole and bisected rat vas deferens
Authors: Boselli C. , Bianchi L. , Grana E. 
Published: November 2003

1 The present study was carried out to look at the differences between the whole and bisected rat vas deferens in response to cumulative and non‐cumulative administration of noradrenaline in terms of sensitivity and maximum response. An effort was made to quantify the parameters characterizing the various components of the mechanical response to single concentrations of the agonist. 2 The sensitivity, as measured by the ‐log EC50 value for noradrenaline, was significantly lower in the prostatic portion than in the whole vas deferens and epididymal portion. The maximum contractions reached by the epididymal and the prostatic half were 65.03 ± 10.43% and 13.84 ± 5.28% of the maximal contraction evoked by noradrenaline in the whole rat vas deferens. 3 Various concentrations of noradrenaline were tested as single concentrations in the three preparations. Three components of the response to noradrenaline were individualized, i.e. an early rapid phasic component followed by a second slower tonic component with spikes superimposed. The time‐course of these components, as well as their ratios, were different depending on the concentration of agonist tested and on which half of the vas deferens was considered. 4 The importance of oxidation of exogenous noradrenaline as well of the neuronal and extraneuronal uptake mechanisms was considered. EDTA was devoid of any action. Cocaine enhanced the potency and the maximum contraction of noradrenaline and all the parameters related to the different phases of the contraction were increased. Hydrocortisone at the highest concentration employed (2 × 10−5M) was able to reduce significantly the ‐log EC50 value of the cumulative concentration–response curve to noradrenaline and both the phasic and tonic components of the contraction to noradrenaline (3 × 10−6M). 5 In conclusion, our evaluation of the parameters of the mechanical response of the whole and bisected vas deferens to noradrenaline rationalize the, often contradictory, findings of the current litterature. Chiefly, the attainment of a careful description of the features of the response to noradrenaline can offer a dependable approach to the study of the underlying mechanisms of the three components.
Calcitonin gene‐related peptide (CGRP)‐evoked inotropism during hyper‐ and hypo‐sensory‐motor innervation in rat atria
Authors: Rubino A. , Ralevic V. , Burnstock G. 
Published: November 2003

1 Positive inotropic responses to calcitonin gene‐related peptide (CGRP) were evaluated in atria isolated from in vivo rat models of hyper‐sensory‐motor innervation (following neonatal guanethidine treatment) and hypo‐sensory‐motor innervation (following neonatal capsaicin treatment), to explore the hypothesis that functional responsiveness of atrial myocardium to CGRP may correlate with tissue levels of the sensory‐motor neurotransmitters. Comparative evaluation of inotropic responses to CGRP following in vitro treatment of atria with guanethidine was also performed. 2 Following long‐term guanethidine treatment, positive inotropic responses to CGRP were significantly attenuated, while supersensitivity to the sympathetic transmitter noradrenaline was shown. Maximal inotropic responses to CGRP (30 nM) were 214.0 ± 28.1 (n = 8) and 146.8 ±21.7 mg (n = 8; P < 0.01) increase of the basal contractile tension in control and treated preparations, respectively. The pD2 values for noradrenaline were 6.71 ± 0.12 (n = 8) and 7.26 ± 0.13 (n = 6; P < 0.01) in control and treated atria, respectively. Acute application of guanethidine in vitro did not modify the positive inotropism by CGRP or the β‐adrenoceptor agonist isoprenaline. 3 Sensory‐motor hypoinnervation following chronic treatment with capsaicin did not affect the inotropic responses to CGRP. Neither guanethidine nor capsaicin treatment affected the contractile apparatus of myocytes, as demonstrated by similar basal contractile tension as well as calcium‐evoked inotropic responses in control and treated preparations. 4 In summary, increased sensory‐motor innervation, following long‐term sympathectomy with guanethidine, resulted in attenuation of the inotropic responses of the rat atrium to CGRP, while no changes in the inotropic responses were seen following sensory‐motor denervation with capsaicin. Down‐regulation of CGRP receptors or altered post‐receptor signalling may be involved in the reduced responsiveness to CGRP.
From audit to effectiveness: an historical evaluation of the changing role of Medical Audit Advisory Groups
Authors: Houghton Guy 
Published: November 2003

MAAGs were introduced as a result of the 1989 White Paper ‘Working for Patients’, with the remit to direct, coordinate and monitor medical audit activities in general practice. They were funded through the new FHSA management budget and each MAAG was responsible to its own FHSA. They were accepted as a completely new institution as a part of the introduction of an innovative management structure in a reformed NHS. When viewed in an historical context, MAAGs can actually be seen as a part of an expanding culture of greater objectivity and critical analysis which has burgeoned in medical practice over the last two decades. Although MAAGs began with an educational role with uniprofessional medical audit, they have embraced multiprofessional clinical audit in primary care in the context of the wider aspects of quality in practice.The last 20 years have seen the development of clinical guidelines, evidence‐based medicine and application of business management theory to clinical quality. All these have reflected the increasing demand for explicit standards of care which has also formed the basis of clinical audit and MAAG activity. MAAGs should be seen as an inevitable concomitant of this historical trend to improve the application of scientific rigour in medical practice. With the adoption of clinical effectiveness, incorporating all these themes, as one of the NHS Executive's six medium‐term priority areas, MAAGs are uniquely placed to act as agents of change to enhance the quality of primary health care.
Improving clinical effectiveness: a practical approach
Authors: Waters E. A. 
Published: November 2003

The publication of the government white paper ‘Working for Patients’ (1989, HMSO) and implementation of subsequent NHS reforms has led to the development of a great number of initiatives designed to improve the quality of patient care and to make the provision of care more clinically and cost effective. Many of these initiatives, whilst laudable, have been developed in isolation and often without proper consideration of how they relate to one another or might practically be implemented throughout the NHS. It has commonly been the case that attempts to transfer the initiative from an environment of high enthusiasm and, often, high resource to the NHS in general has either failed or led to poor application. Strategies to improve clinical effectiveness have not become a feature of the everyday practice of many, let alone most or all, clinicians in the NHS. The result has been their failure significantly to raise standards of care across the NHS as a whole.It is suggested that many of the initiatives are closely related, and more effective implementation in the NHS as a whole may follow attempts to integrate them in a more practical approach to care management within an organization‐wide clinical effectiveness strategy. It is further suggested that this is best achieved by a continuous quality improvement approach focusing on the care process as the centrepiece of the initiative, and that this method will lead to significant improvements not only in clinical effectiveness but also in cost effectiveness. This paper describes a proposed method of achieving these goals.
Identification and elimination of mycoplasmas in fish cell line cultures
Authors: Frerichs G N 
Published: November 2003

AbstractMycoplasma contamination was identified in 11 cell lines derived from both coldwater and warmwater fish using DNA staining, microbiological culture and ELISA test detection methods. Acholeplasma laidlawii and Mycoplasma arginini were present as single or combined infections. Treatment of cells over three to six serial subcultivations with the addition of 0.5 μg m−1 mycoplasma removal agent (MRA) or 10 μg m−1 ciprofloxacin to culture growth medium effectively eliminated all contaminants except for one instance of M. arginini infection.
Histopathological effects of cadmium on the gills of the freshwater fish, Macropsobrycon uruguayanae Eigenmann (Pisces, Atherinidae)
Authors: Randi A S , Monserrat J M , Rodriguez E M , Romano L A 
Published: November 2003

AbstractEvaluations of histopathological lesions in gill tissue were carried out in the freshwater fish Macropsobrycon uruguayanae following 30 and 60 days of exposure to 1.5 mg 1‐1 of cadmium. The study was conducted on both fed and starved animals in order to determine the influence of feeding condition on cadmium toxicity. The main lesions observed and quantified were: (1) hyperplasia of primary lamellar epithelium; (2) hyperplasia of secondary lamellar epithelium; (3) separation of respiratory epithelium; (4) shortening of secondary lamellae; (5) epithelial necrosis; (6) fusion of adjacent secondary lamellae; (7) hypertrophy of respiratory epithelium; (8) lamellar telangiectasis; (9) hyperplasia of chloride cells; (10) mucinous metaplasia; and (11) inflammatory infiltration. Lesions 6, 8, 9 and 11 were only induced by exposure to cadmium, while lesion 4 could be produced only by starvation. Starved fish also showed a reduction in total body weight and length. Lesion 2 was shown to be non‐specific, and produced by either cadmium, starvation or even exposure time. The possible mode of action of the experimental factors are discussed in relation to the observed pathologies.