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The synthesis of elongated hexagonal shape crystalline hydroxyapatite (HA) by chemical precipitation and crystallization by hydrothermal method at 220 °C is presented, with addition of tartaric acid (TA) in small concentrations. In order to study the influence of tartaric acid addition, it was added either at the end of the precipitation stage, or to the Ca precursor (before the P precursor addition), in different molar ratios to the Ca and P precursors, whose molar ratio was kept constant. The phase identification was performed by XRD and FTIR; size and morphology was studied by means of SEM and TEM. The crystallization took place along the c crystallographic axis, with formation of lamellar crystals with hexagonal habit, whose dimensions first decrease with rising tartaric acid concentration and then increase again. The morphology of the HA crystallites changes above a certain amount of tartaric acid admixture. The addition of TA to the Ca precursor, compared to the case of its addition to the already precipitated HA, leads to better results regarding crystallinity. [ABSTRACT FROM AUTHOR]

Abstract: We prospectively evaluated the incidence of blood transfusion in 105 consecutively treated patients (45 men and 60 women) having bimaxillary orthognathic operations, to find out whether type and screen testing are adequate in clinical practice. All patients had Le Fort I osteotomy combined with bilateral sagittal split osteotomy of the ramus. The preoperative routine was restricted to type and screen testing and verification of ABO/Rhesus (Rh) status. Autologous blood donation or routine cross-matching of allogeneic units of blood was not done. Intraoperative haemoglobin concentrations and the need for blood transfusion in patients having bimaxillary osteotomies were recorded in a prospective database. The mean duration of operation was 196min (range 115–325). The median length of hospital stay was 8 days (range 4–16). The mean (SD) reduction in haemoglobin during operation was 34 (16)g/L in men and 32 (10)g/L in women (p =0.32). No patients had an allogeneic blood transfusion. We found that type and screen testing and verification of ABO/Rh status seems to be an adequate precaution to manage blood loss. As reflected by the low rate of transfusion in the present study, severe haemorrhage that requires transfusion of allogeneic blood has become the exception rather than the rule in bimaxillary orthognathic operations. [Copyright &y& Elsevier]

Statement of problem: The osseointegration or fibrous encapsulation of immediately loaded dental implants depends largely on the extent of implant micromovement. The impact of acrylic resin or metal-reinforced acrylic resin provisional restorations on this movement is currently unknown. Purpose: The purpose of this study was to isolate and measure the effect of provisional restoration type on the vertical displacement of adjacent implants under load at 2 locations. Material and methods: Vertical loads ranging from 10-200 N were applied to polymethyl methacrylate resin (n=56) or metal-reinforced acrylic resin provisional restorations (n=56) supported by 4 implants inserted into homogenous artificial bone in a “u-shaped” alignment. Provisional restorations were first loaded in the anterior segment where the provisional restoration was supported by a mesial and distal implant, followed by loading on an extension 8 mm distal to the last implant. Vertical displacement of the 2 implants nearest the load application was measured and recorded using an optical image correlation technique based on photogrammetric principles. Data were subjected to a nonparametric multivariate analysis (generalized Wilcoxon test) and a Mann-Whitney test with a 2-tailed P value (α=.05). Results: There was no significant difference in the vertical implant displacement of the 2 provisional restoration groups when they were loaded in the anterior segment. However, when loads were applied to the distal cantilever, metal reinforcement resulted in less vertical displacement of the next-to-last implant. The mean vertical displacement of the next-to-last implant when supporting an acrylic resin provisional restoration increased from 20 μm ±3 μm (pooled loads of 10-50 N) to 130 μm ±21 μm (pooled loads of 160-200 N), while the vertical displacement of the implant when retaining a metal-reinforced acrylic resin provisional restoration increased from 10 μm ±2 μm to 69 μm ±13 μm under the same loads (P≤.001). A significant difference over load stages (z=-3.22, P<.001) was observed. Conclusions: The choice of material used for a provisional restoration significantly influences the vertical displacement of implants placed in artificial bone. When loads are applied to distal cantilevers, load distribution with metal reinforcement seems more favorable than with unreinforced acrylic resin. (J Prosthet Dent 2008;100:173-182) [Copyright &y& Elsevier]

Abstract: Objectives: Proinflammatory cytokines, matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a role in left ventricular (LV) structural remodeling. We aimed to investigate the effects of cardiac resynchronization therapy (CRT) on serum levels of amino-terminal prohormone B-type natriuretic peptide (NT-proBNP), some interleukins (IL-1β, IL-6, IL-8), MMP-2 and TIMP-2 in patients with chronic heart failure (CHF). Design and methods: We studied 27 patients (15 M/12 F) with CHF, III–IV NYHA class, implanted with a biventricular pacemaker/defibrillator and 40 healthy subjects (23 M/17 F). Blood samples were collected at baseline and 1week, 3, 6, and 12months after CRT device implantation. Cardiac function was assessed echocardiographically. Results: CRT induced significant improvement in the NYHA class (baseline 3.2±0.5 vs. 1.0 at 12months, P=0.0002) and significant LV reverse remodeling, with a 41% (P=0.001) reduction in LV end-systolic volume (LVESV). This was associated with a significant reduction in serum NT-proBNP, IL-6 and IL-8. Positive extracellular matrix remodeling was illustrated by decreasing levels of MMP-2 and increasing TIMP-2. MMP-2/TIMP-2 ratio decreased with 55% (P=0.003) from baseline value at 12months and the correlation with LVESV reduction was 0.41 (P=0.001). Conclusions: Structural response to CRT is associated with reduced immune activation and positive extracellular matrix remodeling. [Copyright &y& Elsevier]