65 resultados para POSTERIOR RESTORATIONS

em Université de Lausanne, Switzerland


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Purpose: More than five hundred million direct dental restorations are placed each year worldwide. In about 55% of the cases, resin composites or compomers are used, and in 45% amalgam. The longevity of posterior resin restorations is well documented. However, data on resin composites that are placed without enamel/dentin conditioning and resin composites placed with self-etching adhesive systems are missing. Material and Methods: The database SCOPUS was searched for clinical trials on posterior resin composites without restricting the search to the year of publication. The inclusion criteria were: (1) prospective clinical trial with at least 2 years of observation; (2) minimum number of restorations at last recall = 20; (3) report on dropout rate; (4) report of operative technique and materials used; (5) utilization of Ryge or modified Ryge evaluation criteria. For amalgam, only those studies were included that directly compared composite resin restorations with amalgam. For the statistical analysis, a linear mixed model was used with random effects to account for the heterogeneity between the studies. P-values under 0.05 were considered significant. Results: Of the 373 clinical trials, 59 studies met the inclusion criteria. In 70% of the studies, Class II and Class I restorations had been placed. The overall success rate of composite resin restorations was about 90% after 10 years, which was not different from that of amalgam. Restorations with compomers had a significantly lower longevity. The main reason for replacement were bulk fractures and caries adjacent to restorations. Both of these incidents were infrequent in most studies and accounted only for about 6% of all replaced restorations after 10 years. Restorations with macrofilled composites and compomer suffered significantly more loss of anatomical form than restorations with other types of material. Restorations that were placed without enamel acid etching and a dentin bonding agent showed significantly more marginal staining and detectable margins compared to those restorations placed using the enamel-etch or etch-and-rinse technique; restorations with self-etching systems were between the other groups. Restorations with compomer suffered significantly more chippings (repairable fracture) than restorations with other materials, which did not statistically differ among each other. Restorations that were placed with a rubber-dam showed significantly fewer material fractures that needed replacement, and this also had a significant effect on the overall longevity. Conclusion: Restorations with hybrid and microfilled composites that were placed with the enamel-etching technique and rubber-dam showed the best overall performance; the longevity of these restorations was similar to amalgam restorations. Compomer restorations, restorations placed with macrofilled composites, and resin restorations with no-etching or self-etching adhesives demonstrated significant shortcomings and shorter longevity.

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OBJECTIVE: We examined the correlation between clinical wear rates of restorative materials and enamel (TRAC Research Foundation, Provo, USA) and the results of six laboratory test methods (ACTA, Alabama (generalized, localized), Ivoclar (vertical, volumetric), Munich, OHSU (abrasion, attrition), Zurich). METHODS: Individual clinical wear data were available from clinical trials that were conducted by TRAC Research Foundation (formerly CRA) together with general practitioners. For each of the n=28 materials (21 composite resins for intra-coronal restorations [20 direct and 1 indirect], 5 resin materials for crowns, 1 amalgam, enamel) a minimum of 30 restorations had been placed in posterior teeth, mainly molars. The recall intervals were up to 5 years with the majority of materials (n=27) being monitored, however, only for up to 2 years. For the laboratory data, the databases MEDLINE and IADR abstracts were searched for wear data on materials which were also clinically tested by TRAC Research Foundation. Only those data for which the same test parameters (e.g. number of cycles, loading force, type of antagonist) had been published were included in the study. A different quantity of data was available for each laboratory method: Ivoclar (n=22), Zurich (n=20), Alabama (n=17), OHSU and ACTA (n=12), Munich (n=7). The clinical results were summed up in an index and a linear mixed model was fitted to the log wear measurements including the following factors: material, time (0.5, 1, 2 and 3 years), tooth (premolar/molar) and gender (male/female) as fixed effects, and patient as random effect. Relative ranks were created for each material and method; the same was performed with the clinical results. RESULTS: The mean age of the subjects was 40 (±12) years. The materials had been mostly applied in molars (81%) and 95% of the intracoronal restorations were Class II restorations. The mean number of individual wear data per material was 25 (range 14-42). The mean coefficient of variation of clinical wear data was 53%. The only significant correlation was reached by OHSU (abrasion) with a Spearman r of 0.86 (p=0.001). Zurich, ACTA, Alabama generalized wear and Ivoclar (volume) had correlation coefficients between 0.3 and 0.4. For Zurich, Alabama generalized wear and Munich, the correlation coefficient improved if only composites for direct use were taken into consideration. The combination of different laboratory methods did not significantly improve the correlation. SIGNIFICANCE: The clinical wear of composite resins is mainly dependent on differences between patients and less on the differences between materials. Laboratory methods to test conventional resins for wear are therefore less important, especially since most of them do not reflect the clinical wear.

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PURPOSE: The purpose of this study was to characterize local distribution and systemic absorption of the tumor necrosis factor (TNF)-alpha inhibitory single-chain antibody fragment (scFv) ESBA105 following topical administration to the eye in vivo. METHODS: Rabbits received ESBA105 as topical eye drops in two dosing regimens. First, pharmacokinetics after the topical route of administration was compared to the intravenous (i.v.) route by means of applying the identical cumulative daily dose of ESBA105. In a second study rabbits received five eye drops daily for six consecutive days in a lower frequency topical dosing regimen. Kinetics and biodistribution of ESBA105 in ocular tissues and fluids as well as in sera were determined in all animals. RESULTS: After topical administration to the eye, ESBA105 quickly reaches therapeutic concentrations in all ocular compartments. Systemic exposure after topical administration is 25,000-fold lower than exposure after i.v. injection of the identical cumulative daily dose. ESBA105 levels in vitreous humor and neuroretina are significantly higher on topical administration than after i.v. injection. Absolute and relative intraocular biodistribution of ESBA105 is different with topical and systemic delivery routes. Compared to its terminal half-life in circulation (7 hours), the vitreal half-life of ESBA105 is significantly enhanced (16-24 hours). CONCLUSIONS: On topical administration, ESBA105 is efficiently absorbed and distributed to all compartments of the eye, whereby systemic drug exposure is very low. Based on its unique intraocular biodistribution and pharmacokinetics and the absolute intraocular levels reached, topical ESBA105 appears highly attractive for treatment of various ophthalmological disorders.

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Posterior microphthalmos (MCOP) is a rare isolated developmental anomaly of the eye characterized by extreme hyperopia due to short axial length. The population of the Faroe Islands shows a high prevalence of an autosomal-recessive form (arMCOP) of the disease. Based on published linkage data, we refined the position of the disease locus (MCOP6) in an interval of 250 kb in chromosome 2q37.1 in two large Faroese families. We detected three different mutations in PRSS56. Patients of the Faroese families were either homozygous for c.926G>C (p.Trp309Ser) or compound heterozygous for c.926G>C and c.526C>G (p.Arg176Gly), whereas a homozygous 1 bp duplication (c.1066dupC) was identified in five patients with arMCOP from a consanguineous Tunisian family. In one patient with MCOP from the Faroe Islands and in another one from Turkey, no PRSS56 mutation was detected, suggesting nonallelic heterogeneity of the trait. Using RT-PCR, PRSS56 transcripts were detected in samples derived from the human adult retina, cornea, sclera, and optic nerve. The expression of the mouse ortholog could be first detected in the eye at E17 and was maintained into adulthood. The predicted PRSS56 protein is a 603 amino acid long secreted trypsin-like serine peptidase. The c.1066dupC is likely to result in a functional null allele, whereas the two point mutations predict the replacement of evolutionary conserved and functionally important residues. Molecular modeling of the p.Trp309Ser mutant suggests that both the affinity and reactivity of the enzyme toward in vivo protein substrates are likely to be substantially reduced.

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OBJECTIVES: We examined the correlation between the quantitative margin analysis of two laboratory test methods (Berlin, Zurich) and the clinical outcome in Class V restorations. METHODS: Prospective clinical studies with an observation period of at least 18 months were searched in the literature, for which laboratory data were also available. The clinical outcome variables were retention loss, marginal discoloration, detectable margins and secondary caries. Forty-four clinical studies matched the inclusion criteria, including 34 adhesive systems for which laboratory data were also present. For both laboratory test methods and the clinical studies, an index was formulated to better compare the in vitro and in vivo results. Linear mixed models which included a random study effect were calculated. As most clinical data were available for 12 and 24 months, the main analysis was restricted to these recall intervals. RESULTS: The comparative analysis revealed a weak correlation between the clinical index and both in vitro indices. The correlation was statistically significant for the Berlin method but not for the Zurich method and only present if studies were compared which used the same composite in the in vitro and in vivo study. When defining specific cut-off values, the prognosis for the good clinical performance of an adhesive system based on in vitro results was 78% (Berlin) or 100% (Zurich). For poor performance it was 67% and 60%, respectively. No correlation was found between both in vitro methods. SIGNIFICANCE: The surrogate parameter "marginal adaptation" of restorations placed in extracted teeth has a mediocre value to predict the clinical performance of an adhesive system in cervical cavities. The composite is an important factor for a successful prediction. The comparison between in vitro/in vivo is sometimes hampered by the great variability of clinical results on the same adhesive system.

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Background: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) and the combined Pons-midbrain score quantify the extent of early ischemic changes in the posterior circulation. We compared the prognostic accuracy of both scores if applied to CT angiography (CTA) source images (CTA-SI) of patients in the Basilar Artery International Cooperation Study (BASICS).Methods: BASICS was a prospective, observational, multi-centre, registry of consecutive patients who presented with acute symptomatic basilar artery occlusion (BAO). Functional outcome was assessed at 1 month. We applied pc-ASPECTS and the combined Pons-midbrain score to CTA-SI by 3-reader-consensus. Readers were blinded to clinical data. We performed multivariable logistic regression analysis, adjusting for thrombolysis, baseline NIHSS score and age, and used the output to derive ROC curves to compare the ability of both scores to discriminate patients with favourable (modified Rankin Scale [mRS] scores 0-3) from patients with unfavourable (mRS scores 4-6) functional outcome.Results: We reviewed CTAs of 158 patients (64% men, mean age 65 _ 15 years, median NIHSS score 25 [0-38], median GCS score 7 [3-15], median onset-to-CTA time 234 minutes [11-7380]). At 1 month, 40 (25%) patients had a favourable outcome, 49 (31%) had an unfavourable outcome (mRS score 4-5) and 69 (44%) were deceased. Both techniques of assessing CTA-SI hypoattenuation in the posterior circulation showed equally good discriminative value in predicting final outcome (C-statistics; area under ROC curve 0.74 versus 0.75, respectively; p_0.37). Pc-ASPECTS dichotomized at _6 versus _6 was an independent predictor of favourable functional outcome (RR _ 2.2; CI95 1.1-4.7; p _ 0.034).Conclusion: Compared to the combined Pons-midbrain score, the pc-ASPECTS score has similar prognostic accuracy to identify patients with a favourable functional outcome in BASICS. Dichotomized pc-ASPECTS (_6 versus _6) is an independent predictor of favourable functional outcome in this population. Author Disclosures: V. Puetz: None. A. Khomenko: None. M.D. Hill: None. I. Dzialowski: None. P. Michel: None. C. Weimar: None. C.A.C. Wijman: None. H. Mattle: None. K. Muir: None. T. Pfefferkorn: None. D. Tanne: None. S. Engelter: None. K. Szabo: None. A. Algra: None. A.M. Demchuk: None. W.J. Schonewille: None.

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Posterior cortical atrophy (PCA) is a group of neurodegenerative dementing disorders characterized by initial predominant visual complaints followed by progressive decline in cognitive functions. The visuospatial and visuoperceptual defects arise from the dysfunction of, respectively, the dorsal (occipito-parietal) and the ventral (occipito-temporal) streams. Clinical symptoms, results of neuropsychological examination, and findings of posterior cerebral atrophy and/or posterior hypoperfusion/hypometabolism contribute to the diagnosis. However, owing to the insidious onset of PCA and the non-specificity of initial symptoms, the diagnosis is often delayed. Specific etiologies include Alzheimer's disease, dementia with Lewy bodies, subcortical gliosis, corticobasal degeneration, and prion-associated diseases. Alzheimer's disease accounts for at least 80 % of PCA cases. Recent research has concentrated on better defining the clinical presentation of PCA, improving neuroimaging analysis, testing new neuroimaging techniques, and developing biological measurements. Selected recent papers on PCA are reviewed in this article.

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Posterior chest wall defects are frequently encountered after excision of tumors as a result of trauma or in the setting of wound dehiscence after spine surgery. Various pedicled fasciocutaneous and musculocutaneous flaps have been described for the coverage of these wounds. The advent of perforator flaps has allowed the preservation of muscle function but their bulk is limited. Musculocutaneous flaps remain widely employed. The trapezius and the latissimus dorsi (LD) flaps have been used extensively for upper and middle posterior chest wounds, respectively. Their bulk allows for obliteration of the dead space in deep wounds. The average width of the LD skin paddle is limited to 10-12 cm if closure of the donor site is expected without skin grafting. In 2001 a modification of the skin paddle design was introduced in order to allow large flaps to be raised without requiring grafts or flaps for donor site closure. This V-Y pattern allows coverage of large anterior chest defects after mastectomy. We have modified this flap to allow its use for posterior chest wall defects. We describe the flap design, its indications, and its limitations with three clinical cases. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266 .

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Stress radiographs have been recommended in order to obtain a better objective quantification of abnormal compartment knee motion. This tool has showed to be superior in quantifying a posterior cruciate ligament (PCL) lesion compared to clinical or arthrometer evaluation. Different radiographic techniques have been described in literature to quantify posterior pathological laxity. In this study we evaluated the total amount of posterior displacement (PTD) and side to side difference (SSD), before and after surgical reconstruction of PCL or PCL and posterolateral complex (PLC), using two different stress radiography techniques (Telos stress and kneeling view). Twenty patients were included in this study. We found a statistical significant difference about both total PTD and SSD among the two techniques preoperatively and at follow-up, with greatest values occurring using the kneeling view. Although stress radiographies has been introduced to allow an objective quantification of laxity in ligamentous injured knee, we believe that further studies on a large numbers of subjects are required to define the relationship between PTD values, measured with stress knee radiography, particularly using kneeling view, and ligamentous knee injury, in order to obtain a real useful tool in the decision making process, as well as to evaluate the outcome after ligamentous surgery.

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Introduction: Accurate registration of the relative timing between the occurrence of sensory events on a sub-second time scale is crucial for both sensory-motor and cognitive functions (Mauk and Buonomano, 2004; Habib, 2000). Support for this assumption comes notably from evidence that temporal processing impairments are implicated in a range of neurological and psychiatric conditions (e.g. Buhusi & Meck, 2005). For instance, deficits in fast auditory temporal integration have been regularly put forward as resulting in phonologic discrimination impairments at the basis of speech comprehension deficits characterizing e.g. dyslexia (Habib, 2000). At least two aspects of the brain mechanisms of temporal order judgment remain unknown. First, it is unknown when during the course of stimulus processing a temporal ,,stamp‟ is established to guide TOJ perception. Second, the extent of interplay between the cerebral hemispheres in engendering accurate TOJ performance is unresolved Methods: We investigated the spatiotemporal brain dynamics of auditory temporal order judgment (aTOJ) using electrical neuroimaging analyses of auditory evoked potentials (AEPs) recorded while participants completed a near-threshold task requiring spatial discrimination of left-right and right-left sound sequences. Results: AEPs to sound pairs modulated topographically as a function of aTOJ accuracy over the 39-77ms post-stimulus period, indicating the engagement of distinct configurations of brain networks during early auditory processing stages. Source estimations revealed that accurate and inaccurate performance were linked to bilateral posterior sylvian regions activity (PSR). However, activity within left, but not right, PSR predicted behavioral performance suggesting that left PSR activity during early encoding phases of pairs of auditory spatial stimuli appears critical for the perception of their order of occurrence. Correlation analyses of source estimations further revealed that activity between left and right PSR was significantly correlated in the inaccurate but not accurate condition, indicating that aTOJ accuracy depends on the functional de-coupling between homotopic PSR areas. Conclusions: These results support a model of temporal order processing wherein behaviorally relevant temporal information - i.e. a temporal 'stamp'- is extracted within the early stages of cortical processes within left PSR but critically modulated by inputs from right PSR. We discuss our results with regard to current models of temporal of temporal order processing, namely gating and latency mechanisms.

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BACKGROUND: The purpose of this work was to characterize the expression of drug and nutrient carriers along the anterior-posterior and crypt-villus axes of the intestinal epithelium and to study the validity of utilizing whole gut tissue rather than purified epithelial cells to examine regional variations in gene expression. RESULTS: We have characterized the mRNA expression profiles of 76 % of all currently known transporters along the anterior-posterior axis of the gut. This is the first study to describe the expression profiles of the majority of all known transporters in the intestine. The expression profiles of transporters, as defined according to the Gene Ontology consortium, were measured in whole tissue of the murine duodenum, jejunum, ileum and colon using high-density microarrays. For nine transporters (Abca1, Abcc1, Abcc3, Abcg8, Slc10a2, Slc28a2, Slc2a1, Slc34a2 and Slc5a8), the mRNA profiles were further measured by RT-PCR in laser micro-dissected crypt and villus epithelial cells corresponding to the aforementioned intestinal regions. With respect to differentially regulated transporters, the colon had a distinct expression profile from small intestinal segments. The majority (59 % for p cutoff < or = 0.05) of transporter mRNA levels were constant across the intestinal sections studied. For the transporter subclass "carrier activity", which contains the majority of known carriers for biologically active compounds, a significant change (p < or = 0.05) along the anterior-posterior axis was observed. CONCLUSION: All nine transporters examined in laser-dissected material demonstrated good replication of the region-specific profiles revealed by microarray. Furthermore, we suggest that the distribution characteristics of Slc5a8 along the intestinal tract render it a suitable candidate carrier for monocarboxylate drugs in the posterior portion of the intestine. Our findings also predict that there is a significant difference in the absorption of carrier-mediated compounds in the different intestinal segments. The most pronounced differences can be expected between the adjoining segments ileum and colon, but the differences between the other adjoining segments are not negligible. Finally, for the examined genes, profiles measured in whole intestinal tissue extracts are representative of epithelial cell-only gene expression.

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OBJECTIVES: To carry out a meta-analysis in order to assess the influencing factors on retention loss and marginal discoloration of cervical restorations made of composites and glass ionomer (derivates). METHODS: The literature was searched for prospective clinical studies on cervical restorations with an observation period of at least 18 months. RESULTS: Fifty clinical studies involving 40 adhesive systems matched the inclusion criteria. On average, 10% of the cervical fillings were lost and 24% exhibited marginal discoloration after 3 years. The variability ranged from 0% to 50% for retention loss and from 0% to 74% for marginal discoloration. Hardly any secondary caries was detected. When linear mixed models with a study and experiment effect were used, the analysis revealed that the adhesive/restorative class had the most significant influence, with 2-step self-etching adhesive systems performing best and 1-step self-etching adhesive systems performing worst; 3-step etch-and-rinse systems, glass ionomers/resin-modified glass ionomers, 2-step etch-and-rinse systems and polyacid-modified resin composites were ranked in between. Restorations placed in teeth whose dentin/enamel had been prepared/roughened showed a statistically significant higher retention rate than those placed in teeth with unprepared dentin (p<0.05). Beveling of the enamel and the type of isolation used (rubberdam/cotton rolls) had no significant influence. SIGNIFICANCE: The clinical performance of cervical restorations is significantly influenced by the type of adhesive system used and/or the adhesive class to which the system belonged and whether the dentin/enamel is prepared or not. 2-Step self-etching- and 3-step etch&rinse systems shall be chosen over 1-step self-etching systems and glass ionomer derivates. The dentin (and enamel) surface shall be roughened before placement of the restoration.