Accuracy of Impression Techniques for Impants. Part 2-Comparison of Splinting Techniques

Purpose: The aim of this study was to compare splinting techniques for impression copings of osseointegrated implants with different angulations.Materials and Methods: Replicas (N = 24) of a metal matrix (control) containing two implants at 90 degrees and 65 degrees in relation to the horizontal surface were obtained by using four impression techniques: Technique 1 (T1), direct technique with square copings without union in open trays; Technique 2 (T2), square copings splinted with dental floss and autopolymerizing acrylic resin; Technique 3 (T3), square copings splinted with dental floss and autopolymerizing acrylic resin, sectioned and splinted again with autopolymerizing acrylic resin; Technique 4 (T4), square copings splinted with prefabricated acrylic resin bar. The impression material was polyether. The replicas were individually scanned to capture the images, which were assessed in a graphic computation program. The program allowed the angulation between the bases of the replicas and the reading screws to be measured. The images of the replicas were compared with the matrix image (control), and the differences in angulations from the control image were calculated. The analysis of variance and the Tukey test for comparisons (p < 0.05) were used for statistical analysis.Results: All groups showed significant differences in the implant angulations in comparison with the control group (p < 0.05). Group T1 showed the highest difference (1.019 degrees) followed by groups T2 (0.747 degrees), T3 (0.516 degrees), and T4 (0.325 degrees), which showed the lowest angular alteration compared to the control group. There were significant differences between inclined and straight implants in all the groups, except in group T4.Conclusions: Based on the results, the splinting of pick-up impression copings is indicated for osseointegrated implant impressions. The square copings splinted with a prefabricated acrylic resin bar presented the best results among the pick-up impression techniques evaluated in this study.

Crystal structure of di-mu(N,S)-thiocyanato-bis[(N-benzylideneaniline-C-2,N)palladium(II)], [Pd(C6H4CH=NC6H5)(mu-SCN)](2)

C28H20N4Pd2S2, monoclinic, P12(1)/c1 (No. 14), a = 11.325(1) Angstrom, b = 13.530(1) Angstrom, c = 17.925(1) Angstrom, beta = 106.23(1)degrees, V = 2637.1 Angstrom(3), Z = 4, R-gt(F) = 0.052, wR(ref)(F-2) = 0.129, T = 293 K.

Crystal structure of di-μ(N,S)-thiocyanato-bis[(N-benzylideneaniline-C 2,N)palladium(II)], [Pd(C6H4CH=NC 6H5)(μ-SCN)]2

C28H20N4Pd2S2, monoclinic, P121/c1 (No. 14), a = 11.325(1) Å, b = 13.530(1) Å, c = 17.925(1) Å, β = 106.23(1)°, V = 2637.1 Å 3, Z = 4, Rgt(F) = 0.052, wRref(F2) = 0.129, T = 293 K. © by Oldenbourg Wissenschaftsverlag.

Participação da via alfa-2 adrenérgica no controle da secreção do hormônio do crescimento no período prépúbere em novilhas da raça Nelore

This study investigated GH secretion after clonidine (alpha-2 adrenergic agonist) treatment in pre-pubertal Nelore heifers. Clonidine (10 mg/kg, IV, 15 min samples for 4 h) was administrated in the same Nelore heifers at eight (n = 4), 12 (n = 5) and 15 (n = 4) months of age. The GH concentration was measured by radioimmunoassay (sensivity = 0.25 ng/mL, CV = 16%). At eight months, clonidine increased GH average concentration, total area of peaks, the total area of GH secretion and increased peak amplitude and reduced time to onset of peak (P < 0.05). At 15 months, the administration of clonidine increased the GH average concentration and at 12 months the increased occurred only in restricted intervals (P < 0.05). Clonidine injection stimulated GH secretion in prepubertal heifers and this effect was more evident in Nelore heifers at eight months compared to 12 and 15 months of age.

325 degrees C thermoluminescence peak growth in quartz related to oxygen vacancies

The thermoluminescence intensity as a function of gamma-ray dose of the 325 degreesC peak, in quartz grains extracted from sea sediments and from fluvial aeolic dunes, is studied. It is found that the response curve at low doses has a concavity directed opposite to that of quartz grains extracted from archaeological potteries. To explain this behavior a model is proposed here based on oxygen vacancies and [AlO4/h](0) centers. The experimentally observed ESR intensity of E-I'-centers as a function of radiation dose can also be explained by this model.