Comparative Efficiency of Removable Mini-Implant Retained Dentures Using Different Attachments in Edentulous Patients

Aim. To compare the efficiency of removable mini-implant retained dentures using different types of attachment.Materials and methods. The study included 51 edentulous patients. The patients were divided into three groups according to the attachment type and abutment shape: 1) ball-and-socket attachment, ball abutment (n = 26); 2) locator attachment, equator abutment, XiVE LOCATOR system (n = 14); 3) bar attachment (n = 11). Removable dentures were made of ordinary acrylic plastic. The placement of intraosseous dental implants with their sublingual engraftment was performed according to the traditional two-stage delayed-load procedure. The efficiency of implants was evaluated using the method of M.Z. Mirgazizov and the eponymous index. The dynamics of vertical bone resorption around implants was determined using dental panoramic radiography (6 months, 1 and 2 years after the treatment). A periotest was performed 6 months after the end of the orthopaedic treatment.Results. The one-year survival rate of implants reached 96.2% in group 1, amounting to 100% in groups 2 and 3. The two-year survival rate came to 92.3% in group 1, reaching 92.9% and 100% in groups 2 and 3, respectively. Inflammatory phenomena characteristic of peri-implantitis were noted one year after the implant placement in 7.7% (n = 2) of patients in group 1 and in 7.1% of patients in group 2, with no inflammatory phenomena being observed in group 3. Two years after the implant placement, peri-implantitis was observed in 19.2% and 21.4% of patients in groups 1 and 2, respectively, coming to 9.1% in group 3. The periotest revealed that six months after the placement, implant stability was higher in group 3 for both the lower and upper jaw (in comparison with groups 1 and 2), as evidenced by the shift in periotest values towards the negative part of the scale.Conclusion. The study revealed that bar attachment, as well as locator attachment (equator abutments), of removable dentures supported by mini implants is more efficient as compared to the ball-and-socket attachment

Generation of surface defects in epitaxial CdxHg1-xTe layers by soft X-ray radiation of laser plasma

The possibility is demonstrated of a selective action of soft X-ray radiation on atoms of an individual element on the surface of a crystal constructed of atoms of several chemical elements

Modes of Escherichia coli Dps Interaction with DNA as Revealed by Atomic Force Microscopy.

Multifunctional protein Dps plays an important role in iron assimilation and a crucial role in bacterial genome packaging. Its monomers form dodecameric spherical particles accumulating ~400 molecules of oxidized iron ions within the protein cavity and applying a flexible N-terminal ends of each subunit for interaction with DNA. Deposition of iron is a well-studied process by which cells remove toxic Fe2+ ions from the genetic material and store them in an easily accessible form. However, the mode of interaction with linear DNA remained mysterious and binary complexes with Dps have not been characterized so far. It is widely believed that Dps binds DNA without any sequence or structural preferences but several lines of evidence have demonstrated its ability to differentiate gene expression, which assumes certain specificity. Here we show that Dps has a different affinity for the two DNA fragments taken from the dps gene regulatory region. We found by atomic force microscopy that Dps predominantly occupies thermodynamically unstable ends of linear double-stranded DNA fragments and has high affinity to the central part of the branched DNA molecule self-assembled from three single-stranded oligonucleotides. It was proposed that Dps prefers binding to those regions in DNA that provide more contact pads for the triad of its DNA-binding bundle associated with one vertex of the protein globule. To our knowledge, this is the first study revealed the nucleoid protein with an affinity to branched DNA typical for genomic regions with direct and inverted repeats. As a ubiquitous feature of bacterial and eukaryotic genomes, such structural elements should be of particular care, but the protein system evolutionarily adapted for this function is not yet known, and we suggest Dps as a putative component of this system

Primers and oligonucleotides.

<p>Primers and oligonucleotides.</p

Complexes formed by Dps with four artificial branched constructs schematically drown on each section.

<p>The sequence of colored circles corresponds to the sequence of the oligonucleotides used (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126504#pone.0126504.t001" target="_blank">Table 1</a>). Panels demonstrate AFM images obtained for free DNA samples and their complexes with Dps (left and right scans, respectively). Assembling of DNA constructs and complex formation were performed as described in Materials and Methods. Insert in the right panel of <b>Fig D</b> exemplifies the 3D image of complexes formed with Y5_Y6_Y8 triplex. Ends of all three branches are clearly visible. White bars represent 100 nm scales.</p

Electrophoretic mobility shift assays performed for Dps complexes with Y-shape constructs Y1_Y2_Y3 (drown in Fig 1B) and Y5_Y6_Y7 (similar to Y5_Y6_Y8 drown in Fig 1D but without single-stranded loop).

<p>The composition of the samples and the molar Dps:DNA ratio are indicated above photos. Branched DNA molecules were assembled from indicated oligonucleotides mixed in equal concentration (2–5 pmol each) and prepared as described in Materials and Methods. Without prior fractionation they were used for complex formation with Dps. The amount of Dps was chosen based on the assumption that all the oligonucleotides formed triplex, as in the case of Y5_Y6_Y7. Indicated molar ratios for Y1_Y2_Y3 are, therefore, overestimated. Gels were calibrated by marker DNA fragments (M) and stained by AgNO_<i>3</i> so as to visualize both DNA molecules and Dps.</p

AFM images.

<p><b>[A]</b>: Dps protein; <b>[B-D]</b>: DNA-fragments containing correspondingly complete regulatory region of gene <i>dps</i> (420 bp, primers <i>dps_</i>F1 and <i>dps_</i>R2), its proximal (259 bp, primers <i>dps_</i>F2 and <i>dps_</i>R2) and distal (214 bp, primers <i>dps_</i>F1 and <i>dps_</i>R1) part. Panels <b>b</b> and <b>c</b>: complexes formed by Dps with 214 bp <b>(b)</b> and 259 bp <b>(c)</b> DNA-fragments. White bar scales represent 100 nm.</p