bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weaning units: lessons from North America?
Authors: Subbe C. P. , Criner G. J. , Baudouin S. V. 
Published: March 2007

SummaryIn the United Kingdom over 5% of critical care beds are occupied by stable patients weaning from mechanical ventilation. In North America, diagnosis related groups (DRGs) were introduced over a decade ago. These provided an economic impetus to develop more cost effective regional weaning centres. The imminent introduction of Payment By Results may encourage similar developments in the UK. The evidence for weaning centres is reviewed and detailed organisational and outcome data from two North American centres presented. These units differ from UK critical care units in terms of nurse : patient ratios and types and numbers of ancillary staff. Limited data, mostly from North America, suggest that weaning centres may be better at improving outcome in ventilator‐dependent patients compared with standard critical care. The existing evidence is not conclusive and highlights the need for UK‐based studies on organisational approaches to the provision of weaning and longer term critical care.
The accuracy of non‐invasive carbon dioxide monitoring: A clinical evaluation of two transcutaneous systems
Authors: Bolliger D. , Steiner L. A. , Kasper J. , Aziz O. A. , Filipovic M. , Seeberger M. D. 
Published: March 2007

SummaryWe determined the accuracy of two transcutaneous carbon dioxide monitoring systems (SenTec Digital Monitor with V‐Sign Sensor and TOSCA 500 with TOSCA Sensor 92) for the measurement of single values and trends in the arterial partial pressure of carbon dioxide in 122 adult patients during major surgery and in 50 adult patients in the intensive care unit. One or several paired measurements were performed in each patient. The first measurement was used to determine the accuracy of a single value of transcutaneous carbon dioxide; the difference between the first and the last measurements was used to analyse the accuracy and to track trends. We defined a 95% limit of agreement of ≤1 kPa as being clinically useful. There was insufficient agreement between transcutaneous carbon dioxide partial pressure values derived from the two systems and arterial carbon dioxide values for both single values and trends as defined by our suggested limit of agreement. We conclude that these systems cannot replace conventional blood gas analysis in the clinical setting studied.
Traumatic pulmonary pseudocysts
Authors: De A. , Peden C. J. , Nolan J. 
Published: March 2007

SummaryWe describe a case of a 19‐year‐old man who developed traumatic pulmonary pseudocysts after a rollover road traffic crash. These were associated with significant pulmonary haemorrhage requiring a period of mechanical ventilation, but resolved without specific intervention. Review of the literature confirms that this rare complication of blunt chest trauma occurs usually in young adults and, although normally benign, can be associated with life‐threatening haemoptysis and secondary infection.
Effects of 2% chlorhexidine and 5.25% sodium hypochlorite on gutta‐percha cones studied by atomic force microscopy
Authors: Valois C. R. A. , Silva L. P. , Azevedo R. B. 
Published: March 2007

AbstractAim  To compare the effects of 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl) on gutta‐percha (GP) cone structure using atomic force microscopy (AFM).Methodology  Two standardized GP cones were sectioned 3 mm from the tip, attached to a glass base and immersed in 2% CHX or 5.25% NaOCl for 1, 5, 10, 20 and 30 min. Untreated GP cones were used as control. Topography and elasticity analyses were performed on 12 different regions located between 1 and 2 mm from the tip. Root mean square (RMS) parameters for contact mode imaging and force modulation microscopy variations were measured. The differences between RMS values were tested by anova with Fisher's protected LSD test for multiple comparisons.Results  There was no deterioration in the topography and physical properties studied when 2% CHX was used in comparison with the control (P < 0.05). The RMS parameter for topography increased after 10 min of 5.25% NaOCl exposure in comparison with the control (P < 0.05). In addition, 5.25% NaOCl increased the elasticity of the GP cone after an immersion time of 1 min in comparison with the control (P < 0.05).Conclusions  Two per cent CHX did not change GP cone structure following up to 30 min exposure. Conversely, 5.25% NaOCl caused elastic changes after 1 min exposure.
Influence of cervical preflaring on apical file size determination
Authors: Pecora J. D. , Capelli A. , Guerisoli D. M. Z. , Spanó J. C. E. , Estrela C. 
Published: March 2007

AbstractAim  To investigate the influence of cervical preflaring with different instruments (Gates‐Glidden drills, Quantec Flare series instruments and LA Axxess burs) on the first file that binds at working length (WL) in maxillary central incisors.Methodology  Forty human maxillary central incisors with complete root formation were used. After standard access cavities, a size 06 K‐file was inserted into each canal until the apical foramen was reached. The WL was set 1 mm short of the apical foramen. Group 1 received the initial apical instrument without previous preflaring of the cervical and middle thirds of the root canal. Group 2 had the cervical and middle portion of the root canals enlarged with Gates‐Glidden drills sizes 90, 110 and 130. Group 3 had the cervical and middle thirds of the root canals enlarged with nickel‐titanium Quantec Flare series instruments. Titanium‐nitrite treated, stainless steel LA Axxess burs were used for preflaring the cervical and middle portions of root canals from group 4. Each canal was sized using manual K‐files, starting with size 08 files with passive movements until the WL was reached. File sizes were increased until a binding sensation was felt at the WL, and the instrument size was recorded for each tooth. The apical region was then observed under a stereoscopic magnifier, images were recorded digitally and the differences between root canal and maximum file diameters were evaluated for each sample.Results  Significant differences were found between experimental groups regarding anatomical diameter at the WL and the first file to bind in the canal (P < 0.01, 95% confidence interval). The major discrepancy was found when no preflaring was performed (0.151 mm average). The LA Axxess burs produced the smallest differences between anatomical diameter and first file to bind (0.016 mm average). Gates‐Glidden drills and Flare instruments were ranked in an intermediary position, with no statistically significant differences between them (0.093 mm average).Conclusions  The instrument binding technique for determining anatomical diameter at WL is not precise. Preflaring of the cervical and middle thirds of the root canal improved anatomical diameter determination; the instrument used for preflaring played a major role in determining the anatomical diameter at the WL. Canals preflared with LA Axxess burs created a more accurate relationship between file size and anatomical diameter.
Physico‐chemical properties of MTA and a novel experimental cement
Authors: Santos A. D. , Moraes J. C. S. , Araújo E. B. , Yukimitu K. , Valério Filho W. V. 
Published: March 2007

AbstractAim  To evaluate the release of calcium ions, pH and conductivity of a new experimental dental cement (EC) and to compare them with those of mineral trioxide aggregate (MTA‐Angelus).Methodology  Five samples of each cement were prepared using plastic tubes 1 mm in diameter and 10 mm long. Each sample was sealed in a test tube containing 10 mL deionized water which was analysed after 24, 48, 72, 96, 192, 240 and 360 h for pH, electrical conductivity and calcium release. The concentration of calcium ions was obtained through atomic absorption spectroscopy technique. The data were analysed statistically using the analysis of variance (anova) and the Student's test (t‐test).Results  The pH of the storage solutions was not affected by the material and the interaction of material with time (P > 0.05). However, the time of immersion was significant (P < 0.01) for both materials. For the electric conductivity and calcium release, the interaction of material with time was statistically significant (P < 0.01), indicating that EC and MTA‐Angelus did not behave in a similar manner.Conclusions  The experimental cement released calcium and increased the pH of the storage solutions in a similar manner to MTA‐Angelus. However, EC showed significantly higher calcium release than commercial MTA‐Angelus after 24 h.
CarisolvTM: an alternative to NaOCl in immature root canals?
Authors: Rahman S. , Whitworth J. M. , Dummer P. M. H. 
Published: March 2007

AbstractAim  To test the null hypothesis that CarisolvTM is no more effective than 1% sodium hypochlorite in cleaning uninstrumented, immature root canals.Methodology  A total of 240 uniform, immature ovine incisors were decoronated at the CEJ level and randomly divided into four groups of 60. After gross pulp extirpation, canals were flooded with normal saline (negative control), 1% NaOCl, CarisolvTM or 5% NaOCl (positive control) and incubated for 10 min (group 1), 20 min (group 2), 30 min (group 3) or 30 min, refreshing irrigant at 10 and 20 min (group 4). SEM photomicrographs of canal wall debris in the apical, middle and coronal thirds were scored against a 5‐point scale. Internal consistency was assessed by κ statistics. Debris scores for different irrigant regimes at different canal levels were analysed by non‐parametric tests (P < 0.05).Results  Canals were consistently cleaner in the coronal and middle than apical thirds. NaOCl (5%) was consistently most effective. CarisolvTM and NaOCl (1%) were no more effective than normal saline in group 1 (P > 0.05), but significantly more effective than normal saline in groups 2 (middle and apical 1/3), 3 and 4 (P < 0.05). Carisolv and NaOCl (1%) had comparable activity in groups 1, 2 (middle and apical thirds) and 3, but NaOCl (1%) was significantly more effective than Carisolv in group 4 (coronal and middle thirds).Conclusions

The ovine incisor model presents opportunities to investigate irrigation regimes under controlled ex‐vivo conditions.
NaOCl (5%) remains the most effective irrigant for rapid debris removal in immature root canals.
CarisolvTM cleans pulp debris from the walls of immature root canals as effectively as NaOCl (1%) during static, unrefreshed wall contact for between 20 and 30 min.
Refreshment of NaOCl (1%) enhances its cleaning ability above that of CarisolvTM.
Root canal preparation with Endo‐Eze AET: changes in root canal shape assessed by micro‐computed tomography
Authors: Paqué F. , Barbakow F. , Peters O. A. 
Published: March 2007

AbstractAim  To evaluate the relative performance of Endo‐Eze Anatomic Endodontic Technology (AET) stainless steel instruments when shaping maxillary molar root canals in vitro.Methodology  Extracted human maxillary molars were scanned, before and after root canal shaping with Endo‐Eze AET, employing micro‐computed tomography (μCT) at an isotropic resolution of 34 μm. Three‐dimensional root canal models were reconstructed and evaluated for volume, surface area, ‘thickness’ (diameter), canal transportation and prepared surface. Preparation errors such as apical zips, perforations and fractured instruments were visually determined from those models. Means were contrasted using anova and Scheffépost‐hoc tests.Results  Volume and surface area increased significantly and similarly in mesiobuccal (mb), distobuccal (db) and palatal (p) canals and gross preparation errors (n = 17) were found. Mean root canal diameters, 5 mm coronal to the apex, increased from 0.31 to 0.52, 0.35 to 0.50 and 0.50 to 0.70 mm for mb, db and p canals, respectively. Mean canal transportation ranged from 0.15 to 0.29, 0.15 to 0.27 and 0.21 to 0.33 mm for apical, middle and coronal root canal levels, respectively, with highest values found for mb canals (P < 0.003). Root canals were significantly straightened during preparation (P < 0.002).Conclusions  In summary, Endo‐Eze AET instruments shaped root canals in maxillary molars with substantial canal transportation, particularly in mesiobuccal root canals. Preparation with this instrument removed high volumes of dentine, even though apical preparation was size 30. Based on the current results, Endo‐Eze AET cannot be recommended for the preparation of teeth with curved root canals.
An assessment of endodontic re‐treatment decision‐making in an educational setting
Authors: Al‐Ali K. , Marghalani H. , Al‐Yahya A. , Omar R. 
Published: March 2007

AbstractAim  To test the applicability of Praxis Concept (PC) theory in endodontic re‐treatment decision‐making amongst dental students of similar backgrounds, but from two dental schools.Methodology  A total of 172 students from two dental schools (n = 97 and n = 75) were asked to select their management choices (from five possible options) for each of six variations on quality (by way of adequacy of root filling) and complexity (by way of absence or presence of a post) of a simulated radiograph of an anterior tooth. The six variations each had five possible levels of periapical condition, giving a total of 30 cases for which management choices were sought. Individual re‐treatment preference scores (RPS) were obtained, from which school and gender differences were compared by t‐test. The association between students’ stated re‐treatment propensities and the different cases was expressed as odds ratios using unconditional logistic regression analysis.Results  There were large inter‐individual variations in RPS within the cases at both schools. Mean RPS for the group was 0.62 (SD 0.14), and did not differ between the schools (P = 0.44), but was significantly lower for males than females (P = 0.01). For all participants and a given case, if re‐treatment was proposed for a particular size of lesion, then all larger lesions for that case were also marked for re‐treatment. Presence of a defective root filling or overfilling reflected a greater propensity for re‐treatment than when the root filling was adequate, whilst the absence/presence of a post had no clear effect on re‐treatment choices.Conclusions  The findings support the explanatory potential of PC theory in endodontic re‐treatment decision‐making in the group investigated, and suggest that factors besides disease status alone, may contribute to the choices that clinicians make.
An evaluation of the influence of passive ultrasonic irrigation on the seal of root canal fillings
Authors: Van Der Sluis L. W. M. , Shemesh H. , Wu M. K. , Wesselink P. R. 
Published: March 2007

AbstractAim  To evaluate the influence of passive ultrasonic irrigation (PUI) on the seal of root canal fillings.Methodology  A total of 40 mandibular premolars were distributed equally into two groups and the root canals were cleaned and shaped; they were then filled with gutta‐percha and AH26 (sealer) using the warm vertical compaction technique with the System B (Analytic Technology, Redmond, WA, USA) device. In one group PUI was applied, after completion of instrumentation and hand‐irrigation. In the other group, PUI was not applied. Thereafter, leakage of glucose was evaluated by measuring its concentration once a week for a total period of 56 days using a glucose penetration model. Differences between the groups in terms of glucose concentrations were statistically analysed with the Mann–Whitney test; the level of significance was set at P = 0.05.Results  After the first month the root fillings in teeth where PUI had been used, sealed the root canal significantly better than in teeth where no PUI had been used (P = 0.017).Conclusion  Root fillings sealed the root canal better when PUI had been used.
Nonendodontic periapical lesions: a retrospective study in Chile
Authors: Ortega A. , Fariña V. , Gallardo A. , Espinoza I. , Acosta S. 
Published: March 2007

AbstractAim  To determine the frequency with which the histopathological diagnosis of periapical lesions contributes to a change in the clinical diagnosis.Methodology  Cases having a clinical diagnosis of disease resulting from dental pulp necrosis were selected from the database of the Oral Pathology Reference Institute between 1975 and 2005. Cases with different histopathological diagnoses were determined and information about age and gender of the patient, location of associated tooth, pulp status and the histopathological diagnosis were recorded. The percentage of nonendodontic periapical lesions was then determined.Results  In the 30‐year period, 43 706 biopsy specimens were received. Overall 4006 (9.13%) had a clinical diagnosis of pulpal necrosis with associated pathosis in the periradicular area. Within this group, 26 cases (0.65%) had a histopathological diagnosis of nonendodontic pathology. Keratocystic odontogenic tumour was the most frequent nonendodontic lesion (11 cases) in the periradicular region followed by central giant cell granuloma (three cases), chronic sinusitis (three cases) and one case each of the following lesions: nasopalatine duct cyst, lateral periodontal cyst, calcifying cystic odontogenic tumour, ameloblastic fibroma, squamous odontogenic tumour, cemental dysplasia, haemangioma, foreign body cell granuloma and amalgam tattoo.Conclusions  The histopathological study of periapical pathosis can occasionally reveal nonendodontic lesions. Odontogenic tumours made up the largest group.
Co‐site digital optical microscopy and image analysis: an approach to evaluate the process of dentine demineralization
Authors: De‐Deus G. , Reis C. M. , Fidel R. A. S. , Fidel S. R. , Paciornik S. 
Published: March 2007

AbstractAim  To introduce and explore the potential of digital optical co‐site microscopy and image analysis for the observation of changes in dentine surfaces during demineralization. The effect of ethylenediamine tetraacetic acid (EDTA) was evaluated quantitatively and longitudinally.Methodology  Three maxillary human molars were sectioned transversely at the cemento‐enamel junction, and the crowns discarded. Subsequently, discs approximately 3 mm thick were cut in the cervical third of the root and a standardized smear layer produced. Co‐site image sequences of the dentine surface subjected to 17% EDTA were obtained over the experimental period (15, 30, 60, 180 and 300 s). Sixteen images were obtained in each dentine sample for each experimental time, thus, a total of 48 image fields were obtained. For each field, an image analysis routine automatically discriminated open dentine tubules and measured their number, area fraction and minimum diameter, thus allowing the quantification of the demineralization process. The Student t‐test was used to analyse the data.Results  The number of open tubules remained essentially constant during the demineralization process. The area fraction increased from 9% to 32%. Tubule minimum diameter increased from 1.5 to 3.0 μm. The changes over time for the area fraction and minimum diameter were significant for comparison between all experimental times (P < 0.05).Conclusions  The methodology developed for longitudinal observation of dentinal surfaces was fast, robust and reproducible. It could be easily extended to other chelating substances, thus contributing to the understanding of the demineralization process and in establishing an optimal time‐effect relationship in the clinical application.
Using clinical audit, qualitative data from patients and feedback from general practitioners to decrease delay in the referral of suspected colorectal cancer
Authors: Davies Elizabeth , Van Der Molen Beverley , Cranston Amanda 
Published: March 2007

AbstractRationale  There was local concern over possible delays in the diagnosis and referral of patients with suspected colorectal cancer and interest in understanding more about patients’ experiences of diagnosis.Aims and objectives  To use clinical audit, qualitative data from patients and feedback from general practitioners (GPs) to identify possible delays in referral, and to decrease these by implementing referral guidelines.Methods  Audit of endoscopy referrals assessed how often these recorded rectal examination and whether patients were seen within 2 weeks. Qualitative interviews with 19 patients explored their experience of referral and diagnosis. Review of 33 case records assessed other possible delays.Results  Most patients referred for endoscopy were seen within 2 weeks (67%, 119/177), but only 47% (71/151) of available referral letters mentioned rectal examination. Patients perceived most delay in secondary care and case records suggested that this occurred after non‐urgent referral. Patients also identified some problems with communication, information and support about the diagnosis. We used the results to stimulate local acceptance of national referral guidelines and wider discussion about care. A consultation exercise with GPs informed the development of a faxable urgent referral pro forma and supporting educational meetings. We designed a database to monitor changes in waiting times and made plans to improve communication and support after diagnosis.Discussion  Feeding back qualitative data from patients together with audit results seemed a powerful lever to stimulate action about hospital delays. Average waiting times dropped quickly and remained low due to the continuing national focus upon them. Seeking GP views may have promoted the use of referral pro formas, but monitoring waiting times distracted from a more thorough evaluation of their use. Qualitative data from patients raised awareness of their experience, but was time‐consuming to collect and we had limited success in using it for specific initiatives around communication and support.
Utility of DNA taxonomy and barcoding for the inference of larval community structure in morphologically crypticChironomus(Diptera) species
Authors: PFENNINGER MARKUS , NOWAK CARSTEN , KLEY CHRISTOPH , STEINKE DIRK , STREIT BRUNO 
Published: March 2007

AbstractBiodiversity studies require species level analyses for the accurate assessment of community structures. However, while specialized taxonomic knowledge is only rarely available for routine identifications, DNA taxonomy and DNA barcoding could provide the taxonomic basis for ecological inferences. In this study, we assessed the community structure of sediment dwelling, morphologically crypticChironomuslarvae in the Rhine‐valley plain/Germany, comparing larval type classification, cytotaxonomy, DNA taxonomy and barcoding. While larval type classification performed poorly, cytotaxonomy and DNA‐based methods yielded comparable results: detrended correspondence analysis and permutation analyses indicated that the assemblages are not randomly but competitively structured. However, DNA taxonomy identified an additional species that could not be resolved by the traditional method. We argue that DNA‐based identification methods such as DNA barcoding can be a valuable tool to increase accuracy, objectivity and comparability of the taxonomic assessment in biodiversity and community ecology studies.