Telleman G, Raghoebar GM, Vissink A, den Hartog L, Huddleston Slater JJR, Meijer HJA. A systematic review of the prognosis of short (<10 mm) dental implants placed in the partially edentulous ...patient. J Clin Periodontol 2011; doi: 10.1111/j.1600‐051X.2011.01736.x.
Aim: This study evaluated, through a systematic review of the literature, the estimated implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients.
Materials and methods: A systematic search was conducted in the electronic databases of MEDLINE (1980–October 2009) and EMBASE (1980–October 2009) to identify eligible studies. Two reviewers independently assessed the methodological quality of the articles using specific study design‐related quality assessment forms.
Results: Twenty‐nine methodologically acceptable studies were selected. A total of 2611 short implants (lengths 5–9.5 mm) were analysed. An increase in implant length was associated with an increase in implant survival (from 93.1% to 98.6%). Heterogeneity between studies was explored by subgroup analyses. The cumulative estimated failure rate of studies performed in the maxilla was 0.010 implants/year, compared with 0.003 found in the studies in the mandible. For studies that also included smokers, the failure rate was 0.008 compared with 0.004 found in studies that excluded smokers. Surface topography and augmentation procedure were not sources of heterogeneity.
Conclusion: There is fair evidence that short (<10 mm) implants can be placed successfully in the partially edentulous patient, although with a tendency towards an increasing survival rate per implant length, and the prognosis may be better in the mandible of non smoking patients.
Osteoporotic vertebral compression fractures frequently result in significant morbidity and health care resource use. For patients with severe and disabling pain, vertebral augmentation ...(vertebroplasty and kyphoplasty) is often considered. Although vertebroplasty was introduced >30 years ago, there are conflicting opinions regarding the role of these procedures in the treatment of osteoporotic vertebral compression fractures. This review article updates clinicians on the published prospective randomized controlled data, including the most recent positive trials that followed initial negative trials in 2009. Analysis of multiple national claim datasets has also provided further insight into the utility of these procedures. Finally, we considered the recent recommendations of national organizations and medical societies that advise on the use of vertebral augmentation procedures for osteoporotic vertebral compression fractures.
Significant elemental segregation is shown to exist within individual hollow silver–gold (Ag–Au) bimetallic nanoparticles obtained from the galvanic reaction between Ag particles and AuCl4 –. ...Three-dimensional compositional mapping using energy dispersive X-ray (EDX) tomography within the scanning transmission electron microscope (STEM) reveals that nanoparticle surface segregation inverts from Au-rich to Ag-rich as Au content increases. Maximum Au surface coverage was observed for nanoparticles with approximately 25 atom % Au, which correlates to the optimal catalytic performance in a three-component coupling reaction among cyclohexane carboxyaldehyde, piperidine, and phenylacetylene.
In this paper we report the successful incorporation of high valence transition metals, i.e. Cr, Mo, W, V, Nb, Ti, Zr into SrFeO3- delta perovskite materials, for potential applications as symmetric ...electrode materials for Solid Oxide Fuel Cells. It is observed that the doping leads to a change from an orthorhombic structure (with partial ordering of oxygen vacancies) to a cubic one (with the oxygen vacancies disordered). These electrodes are chemically compatibles with Ce0.9Gd0.1O1.95 (CGO) and La0.8Sr0.2Ga0.8Mg0.2O3- delta (LSGM) electrolytes at least up to 1100 degree C. Thermal annealing experiments in 5% H2-Ar at 800 degree C also show the stability of the doped samples in reducing conditions, suggesting that they may be suitable for both cathode and anode applications. In contrast, reduction of undoped SrFeO3- delta leads to the observation of extra peaks indicating the formation of the brownmillerite structure with the associated oxygen vacancy ordering. The performance of these electrodes was examined on dense electrolyte pellets of CGO and LSGM in air and 5% H2-Ar. In both atmospheres an improvement in the area specific resistances (ASR) values is observed for the doped samples with respect to the parent compound. Thus, the results show that high valence transition metals can be incorporated into SrFeO3- delta -based materials and can have a beneficial effect on the electrochemical performance, making them potentially suitable for use as cathode and anode materials in symmetrical SOFC.
In this study, aberration-corrected scanning transmission electron microscopy is employed to investigate the morphology of Au clusters formed from the aggregation of single atoms sputtered onto an ...amorphous carbon surface. The morphologies of surface-assembled clusters of
N
> 100 atoms are referenced against the morphologies of size-selected clusters determined from previously published results. We observe that surface-assembled clusters (at the conditions employed here) are approximately spherical in shape. The structural isomers of the imaged clusters have also been identified, and the distribution of structural types is broadly in agreement with those from size-selected cluster deposition sources. For clusters of approximately 147 atoms, we find a preference for icosahedra over decahedra and truncated octahedra, but at this size there is a high proportion of unidentified/amorphous structures. At around 309 atoms, we find a preference for decahedra over icosahedra and truncated octahedra, but over half the structures remain unidentifiable/amorphous. For sizes above approximately 561 atoms we are able to identify most of the structures, and find decahedra are still the most favoured, although in competition with single-crystal fcc morphologies. The similarity in structure between surface-assembled and size-selected clusters from a cluster source provides evidence of the relevance of size-selected cluster studies to clusters synthesised by other, industrially relevant, methodologies.
Au nanoparticles over 100 atoms in size formed
via
surface-growth of sputtered atoms on amorphous carbon are approximately spherical in morphology. The distribution of particle structural isomers was found to match those formed
via
gas-condensation.
Aim: This study evaluated, through a systematic review of the literature, the outcome of single‐implant restorations in the aesthetic zone with natural adjacent teeth, thereby addressing immediate, ...early and conventional implant approaches.
Material and Methods: MEDLINE (1950–2008), EMBASE (1966–2008), and CENTRAL (1800–2008) were searched to identify eligible studies. Two reviewers independently assessed the methodological quality using specific study‐design‐related assessment forms.
Results: Out of 86 primarily selected articles, 19 studies fulfilled the inclusion criteria. A meta‐analysis showed an overall survival rate of 95.5% 95% confidence interval: (93.0–97.1) after 1 year. A stratified meta‐analysis revealed no differences in survival between immediate, early and conventional implant strategies. Little marginal peri‐implant bone resorption was found together with low incidence of biological and technical complications. No significant differences in outcome measures were reported in clinical trials comparing immediate, early or conventional implant strategies.
Conclusion: The included literature suggested that promising short‐term results could be achieved for immediate, early and conventional single‐implants in the aesthetic zone. However, important parameters as aesthetic outcome, soft‐tissue aspects, and patient satisfaction were clearly underexposed. The question whether immediate and early single‐implant therapies would result in better treatment outcomes remained inconclusive due to lack of well‐designed controlled clinical studies.
We report a rapid solution-phase strategy to synthesize alloyed PtNi nanoparticles which demonstrate outstanding functionality for the oxygen reduction reaction (ORR). This one-pot coreduction ...colloidal synthesis results in a monodisperse population of single-crystal nanoparticles of rhombic dodecahedral morphology with Pt-enriched edges and compositions close to Pt1Ni2. We use nanoscale 3D compositional analysis to reveal for the first time that oleylamine (OAm)-aging of the rhombic dodecahedral Pt1Ni2 particles results in Ni leaching from surface facets, producing aged particles with concave faceting, an exceptionally high surface area, and a composition of Pt2Ni1. We show that the modified atomic nanostructures catalytically outperform the original PtNi rhombic dodecahedral particles by more than two-fold and also yield improved cycling durability. Their functionality for the ORR far exceeds commercially available Pt/C nanoparticle electrocatalysts, both in terms of mass-specific activities (up to a 25-fold increase) and intrinsic area-specific activities (up to a 27-fold increase).
This paper presents an investigation of the limitations and optimisation of energy dispersive X-ray (EDX) tomography within the scanning transmission electron microscope, focussing on application of ...the technique to characterising the 3D elemental distribution of bimetallic AgAu nanoparticles. The detector collection efficiency when using a standard tomography holder is characterised using a tomographic data set from a single nanoparticle and compared to a standard low background double tilt holder. Optical depth profiling is used to investigate the angles and origin of detector shadowing as a function of specimen field of view. A novel time-varied acquisition scheme is described to compensate for variations in the intensity of spectrum images at each sample tilt. Finally, the ability of EDX spectrum images to satisfy the projection requirement for nanoparticle samples is discussed, with consideration of the effect of absorption and shadowing variations.
•We investigate the methodology of STEM-EDX tomography of nanoparticles.•We present a time-varied acquisition scheme to compensate for detector shadowing.•The ability of STEM-EDX tomography to meet the projection requirement is discussed.
Aim
The objective of this randomized, double‐blind, placebo‐controlled trial was to study the effect of implant surface decontamination with chlorhexidine (CHX)/cetylpyridinium chloride (CPC) on ...microbiological and clinical parameters.
Material & Methods
Thirty patients (79 implants) with peri‐implantitis were treated with resective surgical treatment consisting of apically re‐positioned flap, bone re‐contouring and surface debridement and decontamination. Patients were randomly allocated to decontamination with 0.12% CHX + 0.05% CPC (test‐group) or a placebo‐solution (without CHX/CPC, placebo‐group). Microbiological parameters were recorded during surgery; clinical and radiographical parameters were recorded before (pre‐) treatment (baseline), and at 3, 6 and 12 months after treatment.
Results
Nine implants in two patients in the placebo‐group were lost due to severe persisting peri‐implantitis. Both decontamination procedures resulted in significant reductions of bacterial load on the implant surface, but the test‐group showed a significantly greater reduction than the placebo‐group (log 4.21 ± 1.89 versus log 2.77 ± 2.12, p = 0.006). Multilevel analysis showed no differences between both groups in the effect of the intervention on bleeding, suppuration, probing pocket depth and radiographical bone loss over time.
Conclusion
Implant surface decontamination with 0.12% CHX + 0.05% CPC in resective surgical treatment of peri‐implantitis leads to a greater immediate suppression of anaerobic bacteria on the implant surface than a placebo‐solution, but does not lead to superior clinical results. The long‐term microbiological effect remains unknown.
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