2,610 research outputs found
Effectiveness of resin-coated gutta-percha cones and a dual-cured, hydrophilic methacrylate resin-based sealer in obturating root canals.
No full textThe introduction of a polybutadiene-diisocyanate-methacylate resin-coating of gutta-percha enables the polyisoprene to be chemically coupled to methacrylate-based resin root canal sealers. This study examined the effectiveness of using passively fitting cones of this type of gutta-percha with a dual-cured version of EncloREZ sealer in obturating cleaned and shaped root canals. The hydrophilic nature of the sealer enabled the creation of an extensive network of 800 to 1200 mu m long sealer resin tags after removal of the encloclontic smear layer. Although no adhesive was employed, thin hybrid layers in root dentin were observed when EDTA was used as the final rinse, Nevertheless, interfacial gaps and silver leakage could be,observed along the sealer-dentin interfaces that might be attributed predominantly to polymerization shrinkage of the sealer. Gaps and silver leakage were also identified between the gutta-percha resin-coating and the sealer
HYBRYD ROOT SEAL (METASEAL)CREATES HYBRID LAYERS IN RADICULAR DENTIN ONLY WHEN EDTA IS USED AS A FINAL RINSE
No full textABSTRACT: Purpose: To test if the hybrid layer formation by Hybrid Root SEAL (Sun Medical Co.), a 4-METAcontaining
auto-adhesive self-etching root canal sealer, is affected by the sequence of irrigants employed for removing
canal wall smear layers during root canal treatment. Methods: Single-rooted teeth were shaped and irrigated with EDTA
as initial rinse/NaOCl as active final rinse (Group 1), or NaOCl as initial rinse/EDTA as active final rinse (Group 2). All
canals were obturated with Hybrid Root SEAL using a single-cone technique. Root slices derived from the coronal, middle
and apical thirds of the roots were processed for transmission electron microscopy after removing the gutta-percha, leaving
the sealer intact. Additional filled canals from the two groups were evaluated for fluid leakage. Results: Hybrid layer was
absent in Group 1 and was present only when a collagen matrix was produced by EDTA demineralization (Group 2).
Significantly more leakage (4.03 ± 1.94 μLmin-1 vs. 1.50 ± 0.42 μLmin-1; P< 0.05) was observed in the absence of dentin
hybridization. (Am J Dent 2009;22:299-303)
Does Hybridization of Intraradicular Dentin Really Improve Fiber Post Retention in Endodontically Treated Teeth?
No full textThis study tested the hypothesis that hybridization of intraradicular dentin eliminates interfacial gaps, thereby improving the coronal seal and retention of teeth restored with fiber posts. Post spaces were bonded with two types of fiber posts, using the corresponding etch-and-rinse adhesives and dual-cured resin cements. Longitudinal sections of the interfaces were examined for dentin hybridization in the coronal- and middle-thirds of the root canals. Resin replicas of these sections were evaluated for interfacial gap formation. Although intraradicular dentin hybridization was not compromised irrespective of whether the adhesives were light-cured before cementation, the universal occurrence of interfacial gaps along the hybrid layer surface or the post-cement interface reflects the challenge in bonding to post spaces with low compliance and high C-factors. The clinical success associated with bonded fiber posts is probably due predominantly to frictional retention
Improving the performance of EndoREZ root canal sealer with a dual-cured two-step self-etch adhesive. II. Apical and coronal seal
No full textThis study tested the hypothesis that the seal of EndoREZ may be improved with an adhesive-modified technique. Instrumented single-rooted teeth were filled with: (a) Warm vertical compaction with AH Plus (control); (b). EndoREZ with master cones and passive application of accessory cones; (c) Application of Clearfil Liner Bond 2V before EndoREZ and gutta-percha condensation. Leakage was assessed by fluid filtration at 10 psi before root resection and after 3 to 12 mm apical resections. Statistical analyses revealed significant differences in filling technique and resection lengths. EndoREZ exhibited significantly higher overall leakage, while no difference was found between AH Plus and the adhesive-modified EndoRez technique. Apical resection of EndoREZ to 12 mm exhibited more leakage than all other interactions, but was not significantly different from the same material resected to 9 mm. Although EndoREZ exhibited an acceptable apical seal, its coronal seal may be improved with the use of a dual-cured self-etch adhesive
Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization
No full textGeophysical subsurface characterization techniques could, due to their non-invasive nature, play a crucial role in the design and subsequent construction of infrastructure in urban & industrial environ- ments. Geo-data specialist company Fugro sees potential in upgrading their current ambient-seismic- noise-tomography workflow, to make use of state-of-the-art inversion schemes with the main goal of increasing the quality and accuracy of the initial-site characterization delivered to clients. In this thesis I explore the feasibility of utilizing the reverse-jump Markov chain Monte Carlo (rj-McMC) algorithm for the inversion of ambient seismic noise for characterization in urban & industrial environments. Specif- ically, testing the potential of scaling down this inversion algorithm to fit in a small scale, near-surface framework. To achieve this, I first carried out analyses to evaluate the appropriate Rayleigh wave frequency range, after which realistic noise hyperparameters, suited for this reduced scale problem, were obtained. Because of the potential exploitation of in-situ borehole measurements, I reformulated the Bayesian prior within the rj-McMC algorithm to implement these constraining shear wave velocity values appropriately. I conducted extensive synthetic experiments to gain insight into the behavior of this adapted algorithm, from which it was concluded that the inherent dynamic discretization partially prevents these constraints from being implemented to their full extent. Nevertheless, promising results lead me to conclude that the use of the rj-McMC algorithm for application in near-surface urban & industrial environments is feasible.Applied Geophysics | IDEA Leagu
Reduction in antimicrobial substantivity of MTAD following initial sodium hypochlorite Irrigation
No full textPotential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 105 cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by reactive oxygen species. © 2006 American Association of Endodontists
Clowns, Fools, and Killers: An Exploration of Horror, Comedy, and Madness Through the Roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare\u27s Richard III
No full textThis document is a thesis submitted in partial fulfillment of the Master of Fine Arts degree in Theatre Arts with a Concentration in Musical Theatre. It is a detailed account of author RJ Magee’s artistic and scholarly process in creating the roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare’s Richard III. The production was performed as part of Minnesota State University, Mankato’s mainstage season in October of 2022. In five chapters, this thesis chronicles the actor’s process: a preproduction analysis, a historical and critical perspective, a rehearsal and performance journal, a post-production analysis, and a process development analysis. Appendices and works cited are included
Radiation-induced root surface caries restored with glass-ionomer cement placed in conventional and ART cavity preparations: Results at two years
No full textThe document attached has been archived with permission from the Australian Dental Association (8th Jan 2008). An external link to the publisher’s copy is included.Background: There are no published studies comparing the clinical performances of more-viscous glass-ionomer cement (GIC) restorations when placed using conventional and atraumatic restorative treatment (ART) cavity preparation methods to restore root surface caries. Methods: One dentist used encapsulated Fuji IX GP and Ketac-Molar to restore 72 conventional and 74 ART cavity preparations for 15 patients who had received cervicofacial radiation therapy. Two assessors evaluated the restorations at six, 12, and 24 months for retention, marginal defects and surface wear, and recurrent caries. Results: After two years, the cumulative restoration successes were 65.2 per cent for the conventional and 66.2 per cent for the ART cavity preparations, without statistical or clinical significance (P>0.50). Restoration dislodgement accounted for 82.8 per cent and marginal defects for 17.2 per cent of all failures. There were no instances of unsatisfactory restoration wear or recurrent caries observed. Teeth with three or more restored cervical surfaces accounted for 79.3 per cent of all failures (P<0.0001). Conclusions: For root surface caries restored with GIC, the use of hand instruments only with the ART method was an equally effective alternative to conventional rotary instrumentation for cavity preparation. Larger restorations had higher failures, usually from dislodgement.JY Hu, XC Chen, YQ Li, RJ Smales and KH Yi
Paediatric use of melatonin (Author reply to D. J. Kennaway).
No full textComment on
Paediatric use of melatonin. [Eur J Paediatr Neurol. 2015]
Current role of melatonin in pediatric neurology: clinical recommendations. [Eur J Paediatr Neurol. 2015
Platelet-rich plasma and macular hole surgery: A clue to their mode of action and the influence of anti-platelet agents
No full text\ua9 The Author(s) 2022. Purpose: To present a case of refractory full-thickness macular hole (FTMH), in which autologous platelet-rich plasma (aPRP) was used on two consecutive occasions, and associated with successful closure only after complete cessation of anti-platelet therapy. Methods: Interventional case report. Results: A 63-year-old male with Alport syndrome underwent pars plana vitrectomy with internal limiting membrane peeling and gas for a large FTMH. The patient was on systemic anti-platelet agents for coronary disease. Post-operatively, the FTMH remained open and repeated surgery, augmented with aPRP, was performed. Although a thick pre-retinal coagulum was evident on optical coherence tomography on day one post-surgery, the second surgery failed. Ultimately, successful aPRP-augmented surgical closure of the FTMH was achieved only after complete cessation of systemic anti-platelet agents. Conclusion: Appropriate management of anti-platelet therapy may be relevant when planning aPRP use, though further large-scale studies are needed to assess the precise effect of anti-platelet therapy on the efficacy of aPRP, and to confirm the potential role of aPRP in patients with Alport syndrome
- …
