Evaluation of accuracy of complete-arch multiple-unit abutment-level dental implant impressions using different impression and splinting materials.

Purpose: This in vitro study evaluated the accuracy of multiple-unit dental implant casts obtained from splinted or nonsplinted direct impression techniques using various splinting materials by comparing the casts to the reference models. The effect of two different impression materials on the accuracy of the implant casts was also evaluated for abutment-level impressions. Materials and Methods: A reference model with six internal-connection implant replicas placed in the completely edentulous mandibular arch and connected to multi-base abutments was fabricated from heat-curing acrylic resin. Forty impressions of the reference model were made, 20 each with polyether (PE) and polyvinylsiloxane (PVS) impression materials using the open tray technique. The PE and PVS groups were further subdivided into four subgroups of five each on the bases of splinting type: no splinting, bite registration PE, bite registration addition silicone, or autopolymerizing acrylic resin. The positional accuracy of the implant replica heads was measured on the poured casts using a coordinate measuring machine to assess linear differences in interimplant distances in all three axes. The collected data (linear and three-dimensional [3D] displacement values) were compared with the measurements calculated on the reference resin model and analyzed with nonparametric tests (Kruskal-Wallis and Mann-Whitney). Results: No significant differences were found between the various splinting groups for both PE and PVS impression materials in terms of linear and 3D distortions. However, small but significant differences were found between the two impression materials (PVS, 91 mu m; PE, 103 mu m) in terms of 3D discrepancies, irrespective of the splinting technique employed. Conclusions: Casts obtained from both impression materials exhibited differences from the reference model. The impression material influenced impression inaccuracy more than the splinting material for multiple-unit abutment-level impressions.Article Link : http://www.ncbi.nlm.nih.gov/pubmed/2427891

Tracheobronchial Foreign Bodies

foreign bodies, the means by which they gain accessand the measures by which accidental aspiration canbe prevented.Methods: Bronchoscopy was performed in 39 patientswho presented with a suspicion of foreign body aspirationduring a three-year period (Jan 2002 – Dec 2004) in theDepartment of ENT, Holy Family Hospital, Rawalpindi.Results: The common symptoms were sudden onset ofdyspnoea and cough. Whistle was commonest objectremoved (46.15%). Majority of patients were above tenyears of age (38.46%). Left main bronchus was thecommonest site of involvement.Conclusion: Foreign body aspiration should besuspected when there is sudden onset of respiratorysymptoms, even in the absence of a history of aspiration.Emergency bronchoscopy facility should be available inall hospitals. Mass awareness should be created throughelectronic media and family physicians, to decrease theincidence of such accidents

Gene diversity among some endogamous population of Amravati District, Maharashtra, India.

The present work deals with the distribution of ABO, Rh and sickling alleles as markers to study the genetic structure and micro-demarcation among castes and tribal populations from the Amravati district of Maharashtra. Three loci namely, ABO, Rh and sickling were selected to measure the relative frequency of respective alleles in ten (10) endogamous populations inhabiting the Amravati District. The ABO locus was found to be less polymorphic when compared with other loci. On the other hand, Rh and sickling loci were found to be more polymorphic. Construction of a dendrogram using allele frequency data reveals an interesting relationship among the caste and tribe. An analysis shows three major clades comprising A, B and C. Clade A comprises Islamic Dawoodi Bohra and Hindu Gujrati. Clade B comprises the upper castes, Brahmin, Jain, Kashmiris and Kunbis, while Clade C shows Gonds and Katchhi. This study is a first attempt to provide a genetic landscape of castes and tribes inhabiting the Vidarbha region. The findings are discussed in light of the historical, anthropological and genetic data available for the studied group

Monopole Percolation in the Compact Abelian Higgs Model

We have studied the monopole-percolation phenomenon in the four dimensional Abelian theory that contains compact U(1) gauge fields coupled to unitary norm Higgs fields. We have determined the location of the percolation transition line in the plane $(\beta_g, \beta_H)$. This line overlaps the confined-Coulomb and the confined-Higgs phase transition lines, originated by a monopole-condensation mechanism, but continues away from the end-point where this phase transition line stops. In addition, we have determined the critical exponents of the monopole percolation transition away from the phase transition lines. We have performed the finite size scaling in terms of the monopole density instead of the coupling, because the density seems to be the natural parameter when dealing with percolation phenomena.Comment: 13 pages. REVTeX. 16 figs. included using eps

Appearance of symmetry, beauty, and health in human faces

Symmetry is an important concept in biology, being related to mate selection strategies, health, and survival of species. In human faces, the relevance of left-right symmetry to attractiveness and health is not well understood. We compared the appearance of facial attractiveness, health, and symmetry in three separate experiments. Participants inspected front views of faces on the computer screen and judged them on a 5-point scale according to their attractiveness in Experiment 1, health in Experiment 2, and symmetry in Experiment 3. We found that symmetry and attractiveness were not strongly related in faces of women or men while health and symmetry were related. There was a significant difference between attractiveness and symmetry judgments but not between health and symmetry judgments. Moreover, there was a significant difference between attractiveness and health. Facial symmetry may be critical for the appearance of health but it does not seem to be critical for the appearance of attractiveness, not surprisingly perhaps because human faces together with the human brain have been shaped by adaptive evolution to be naturally asymmetrical

Monopole Percolation in pure gauge compact QED

The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter $n_{max}/n_{tot}$ previously introduced by Hands and Wensley in the study of the percolation transition observed in non-compact QED. A correlation between these parameters and the energy (action) at the phase transition has been observed. We conclude that the order parameter $n_{max}/n_{tot}$ is a sensitive probe for studying the phase transition of pure gauge compact QED.Comment: LaTeX file + 4 PS figures, 12 pag., Pre-UAB-FT-308 ILL-(TH)-94-1