28 resultados para capsule filling

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION: The aim of apical surgery is to hermetically seal the root canal system after root-end resection, thereby enabling periradicular healing. The objective of this nonrandomized prospective clinical study was to report results of 2 different root-end preparation and filling methods, ie, mineral trioxide aggregate (MTA) and an adhesive resin composite (Retroplast). METHODS: The study included 353 consecutive cases with endodontic lesions limited to the periapical area. Root-end cavities were prepared with sonic microtips and filled with MTA (n = 178), or alternatively, a shallow concavity was prepared in the cut root face, with subsequent placement of an adhesive resin composite (Retroplast) (n = 175). Patients were recalled after 1 year. Cases were defined as healed when no clinical signs or symptoms were present and radiographs demonstrated complete or incomplete (scar tissue) healing of previous radiolucencies. RESULTS: The overall rate of healed cases was 85.5%. MTA-treated teeth demonstrated a significantly (P = .003) higher rate of healed cases (91.3%) compared with Retroplast-treated teeth (79.5%). Within the MTA group, 89.5%-100% of cases were classified as healed, depending on the type of treated tooth. In contrast, more variable rates ranging from 66.7%-100% were found in the Retroplast group. In particular, mandibular premolars and molars demonstrated considerably lower rates of healed cases when treated with Retroplast. CONCLUSIONS: MTA can be recommended for root-end filling in apical surgery, irrespective of the type of treated tooth. Retroplast should be used with caution for root-end sealing in apical surgery of mandibular premolars and molars.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION: Apical surgery has seen continuous development with regard to equipment and surgical technique. However, there is still a shortage of evidence-based information regarding healing determinants. The objective of this meta-analysis was to review clinical articles on apical surgery with root-end filling in order to assess potential prognostic factors. METHODS: An electronic search of PubMed and Cochrane databases was performed in 2008. Only studies with clearly defined healing criteria were included, and data for at least two categories per prognostic factor had to be reported. Prognostic factors were divided into patient-related, tooth-related, or treatment-related factors. The reported percentages of healed teeth ("the healed rate") were pooled per category. The statistical method of Mantel-Haenszel was applied to estimate the odds ratios and their 95% confidence intervals. RESULTS: With regard to tooth-related factors, the following categories were significantly associated with higher healed rates: cases without preoperative pain or signs, cases with good density of root canal filling, and cases with absence or size < or = 5 mm of periapical lesion. With regard to treatment-related factors, cases treated with the use of an endoscope tended to have higher healed rates than cases without the use of an endoscope. CONCLUSIONS: Although the clinician may be able to control treatment-related factors (by choosing a certain technique), patient- and tooth-related factors are usually beyond the surgeon's power. Nevertheless, patient- and tooth-related factors should be considered as important prognostic determinants when planning or weighing apical surgery against treatment alternatives.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We investigated the inflammatory response to, and the osteoinductive efficacies of, four polymers (collagen, Ethisorb, PLGA and Polyactive) that bore either an adsorbed (fast-release kinetics) or a calcium-phosphate-coating-incorporated (slow-release kinetics) depot of BMP-2. Titanium-plate-supported discs of each polymer (n = 6 per group) were implanted at an ectopic (subcutaneous) ossification site in rats (n = 48). Five weeks later, they were retrieved for a histomorphometric analysis of the volumes of ectopic bone and foreign-body giant cells (a gauge of inflammatory reactivity), and the degree of polymer degradation. For each polymer, the osteoinductive efficacy of BMP-2 was higher when it was incorporated into a coating than when it was directly adsorbed onto the material. This mode of BMP-2 carriage was consistently associated with an attenuation of the inflammatory response. For coated materials, the volume density of foreign-body giant cells was inversely correlated with the volume density of bone (r(2) = 0.96), and the volume density of bone was directly proportional to the surface-area density of the polymer (r(2) = 0.97). Following coating degradation, other competitive factors, such as the biocompatibility and the biodegradability of the polymer itself, came into play.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

http://www.woodheadpublishing.com/en/book.aspx?bookID=1598

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Experiments were designed to investigate the suitability of a combination of a short manual teat stimulation with a short latency period before teat cup attachment to induce and maintain oxytocin release and milk ejection without interruption. In Experiment 1, seven dairy cows in mid lactation were manually pre-stimulated for 15, 30 or 45 s, followed by either 30 s or 45 s of latency period. It was shown that all treatments induced a similar release of oxytocin without interruption until the end of milking. In particular, the latency period of up to 45 s did not cause a transient decrease of oxytocin concentration. In Experiment 2, milking characteristics were recorded in seven cows each in early, mid, and late lactation, respectively. Because the course of milk ejection depends mainly on the degree of udder filling, individual milkings were classified based on the actual degree of udder filling which differs between lactational stages but also between morning and evening milkings. All animals underwent twelve different udder preparation treatments, i.e. 15, 30, or 45 s of pre-stimulation followed by latency periods of 0, 30, 45, or 60 s. Milking characteristics were recorded. Total milk yield, main milking time and average milk flow rate did not differ between treatments if the degree of udder filling at the start of milking was >40% of the maximum storage capacity. However, if the udder filling was <40%, main milking time was decreased with the duration of a latency period up to 45 s, independent of duration of pre-stimulation. Average milk flow at an udder filling of <40% was highest after a pre-stimulation of 45 s followed by a latency period of another 45 s. In contrast, average milk flow reached its lowest values at a pre-stimulation of 15 s without additional latency period. However, average milk flow after a 15-s pre-stimulation increased with increasing latency period. In conclusion, a very short pre-stimulation when followed by a latency period up to 45 s before teat cup attachment remains a suitable alternative for continuous stimulation to induce milk ejection.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Joint-preserving hip surgery, either arthroscopic or open, increasingly is used for the treatment of symptomatic femoroacetabular impingement (FAI). As a consequence of surgery, thickening of the joint capsule and intraarticular adhesions between the labrum and joint capsule and between the femoral neck and the joint capsule have been observed. These alterations are believed to cause persistent pain and reduced range of motion. Because the diagnosis is made with MR arthrography, knowledge of the normal capsular anatomy and thickness on MRI in patients is important. To date there is no such information available.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The polysaccharide capsule of Streptococcus pneumoniae defines over ninety serotypes, which differ in their carriage prevalence and invasiveness for poorly understood reasons. Recently, an inverse correlation between carriage prevalence and oligosaccharide structure of a given capsule has been described. Our previous work suggested a link between serotype and growth in vitro. Here we investigate whether capsule production interferes with growth in vitro and whether this predicts carriage prevalence in vivo. Eighty-one capsule switch mutants were constructed representing nine different serotypes, five of low (4, 7F, 14, 15, 18C) and four of high carriage prevalence (6B, 9V, 19F, 23F). Growth (length of lag phase, maximum optical density) of wildtype strains, nontypeable mutants and capsule switch mutants was studied in nutrient-restricted Lacks medium (MLM) and in rich undefined brain heart infusion broth supplemented with 5% foetal calf serum (BHI+FCS). In MLM growth phenotype depended on, and was transferred with, capsule operon type. Colonization efficiency of mouse nasopharynx also depended on, and was transferred with, capsule operon type. Capsule production interfered with growth, which correlated inversely with serotype-specific carriage prevalence. Serotypes with better growth and higher carriage prevalence produced thicker capsules (by electron microscopy, FITC-dextran exclusion assays and HPLC) than serotypes with delayed growth and low carriage prevalence. However, expression of cpsA, the first capsule gene, (by quantitative RT-PCR) correlated inversely with capsule thickness. Energy spent for capsule production (incorporation of H3-glucose) relative to amount of capsule produced was higher for serotypes with low carriage prevalence. Experiments in BHI+FCS showed overall better bacterial growth and more capsule production than growth in MLM and differences between serotypes were no longer apparent. Production of polysaccharide capsule in S. pneumoniae interferes with growth in nutrient-limiting conditions probably by competition for energy against the central metabolism. Serotype-specific nasopharyngeal carriage prevalence in vivo is predicted by the growth phenotype.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[1] A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth, the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation, located inside a putative shoreline of the ancient ocean, has a low dielectric constant compared with that of typical volcanic materials. We show that the measured value is only consistent with low-density sedimentary deposits, massive deposits of ground-ice, or a combination of the two. In contrast, radar observations indicate a distribution of shallow ground ice in equilibrium with the atmosphere in the south polar region. We conclude that the northern plains are filled with remnants of a late Hesperian ocean, fed by water and sediments from the outflow channels about 3 Gy ago.