Optical impression method to measure three-dimensional position and orientation of dental implants using an optical tracker

Objectives: The aim of this study was to devise an optical impression method that could make impressions of dental implants accurately and rapidly. Materials and methods: Four paper markers (4 × 3 mm, 8 × 6 mm, 16 × 12 mm, and 24 × 18 mm) and one titanium marker (8 × 6 mm) were prepared to determine the measuring accuracy of the three-dimensional optical tracker. For a proposed and conventional impression taking method, we compared the reproduction accuracies of the positions and orientations of dental implants and the times to obtain impressions. Finally, we fabricated computer-aided designing (CAD)/computer-aided manufacturing (CAM) superstructure frameworks to determine the adaptation accuracy. Results: The 8 × 6-mm titanium marker was optimal among the prepared markers. Dental implants made by the proposed and conventional impression taking methods had measurement errors of 71 ± 31 μm and 32 ± 18 μm, respectively. The proposed method took a significantly shorter time to obtain an impression than did the conventional method. The connection between the CAD/CAM superstructure frameworks and four implant analogs had uplifts of 55 ± 10 μm, 94 ± 35 μm, 2 ± 1 μm, and 66 ± 3 μm. Conclusion: Our proposed method and fabricated titanium markers enabled us to measure the positions and orientations of dental implants both accurately and rapidly. We then used the reproducible measurement results for the positions and orientations of the dental implants to fabricate CAD/CAM superstructure frameworks within an acceptable accuracy range. © 2012 John Wiley & Sons A/S.This is the pre-peer reviewed version of the following article: Ono S., Yamaguchi S., Kusumoto N., et al. Optical impression method to measure three-dimensional position and orientation of dental implants using an optical tracker. Clinical Oral Implants Research 24, 1117 (2013), which has been published in final form at https://doi.org/10.1111/j.1600-0501.2012.02519.x.. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

EVALUATION OF TORQUE MOMENT IN ESTHETIC BRACKETS

Objectives: To examine the torque moment that occurs between esthetic brackets and bendable alloy (stainless steel [SS], titanium-molybdenum [Ti-Mo], and titanium-niobium [Ti-Nb]) wires. Materials and Methods: This study examined ceramic (CR), zirconium oxide (ZC), polycarbonate (PC), and conventional metallic brackets (MT) (upper, 0.018-inch and 0.022-inch slots) combined with SS, Ti-Mo, and Ti-Nb wires using elastic module ligation. The torque moments delivered by various wire and bracket combinations were measured using a torque gauge apparatus. The wire torque angles at 5–40° were examined. Results: The torque value increased in the order of CR, ZC, MT, and PC brackets for both 0.018-inch and 0.022-inch slots. The fracture points of the CR and ZC brackets combined with SS and Ti-Mo wires were approximately more than 30° and 35°, respectively. No fracture points were detected in the combination of ZC brackets and Ti-Nb wires. Conclusions: The current study identified the material characteristics of CR, ZR, and PC brackets during torque tooth movements. The present results demonstrate a characteristic combined effect between different esthetic brackets and bendable alloy wires

Magnetization and transport properties in the superconducting Pr2_{2}Ba4_{4}Cu7_{7}O15−δ_{15-\delta} with metallic double-chain

We have reported the effect of pressure on the magnetization, and transport properties in the nominal composition Pr$_{2}$Ba$_{4}$Cu$_{7}$O$_{15-\delta}$ synthesized by a sol-gel technique. A reduction treatment of the as-sintered sample in vacuum causes higher superconductivity achieving $T_{c,on}=\sim 30$ K for $\delta =0.94$. Application of hydrostatic pressure on the oxygen depleted sample enhances its onset temperature up to 36 K at 1.2 GPa, indicating the nearly optimum doping level of the charge carrier in comparison to the pressure dependence of lower $T_{c}$ samples with $\delta =0.45$. Seebeck coefficient of the superconducting sample shows a metallic conduction, followed by a clear drop below $T_{c,on}$ and is in its temperature dependence below 100 K quite different from that of the non-superconducting one. This finding strongly suggests a dramatic change of the electronic state along the CuO double chain due to the reduction treatment for the appearance of superconductivity .Comment: 5 pages,4 figure

Blood Pressure and Arterial Stiffness

Background—The difference in the predictive ability of the brachial-ankle pulse wave velocity (baPWV) and its stiffness index β-transformed value (β-baPWV, ie, baPWV adjusted for the pulse pressure) for the development of pathophysiological abnormalities related to cardiovascular disease or future occurrence of cardiovascular disease was examined. Methods and Results—In study 1, a 7-year prospective observational study in cohorts of 3274 men and 3490 men, the area under the curve in the receiver operator characteristic curve analysis was higher for baPWV than for β-baPWV for predicting the development of hypertension (0.73, 95% CI=0.70 to 0.75 versus 0.59, 95% CI=0.56 to 0.62; P<0.01) and/or the development of retinopathy (0.78, 95% CI=0.73 to 0.82 versus 0.66, 95% CI=0.60 to 0.71; P<0.01) by the end of the study period. During study 2, a 3-year observation period on 511 patients with coronary artery disease, 72 cardiovascular events were confirmed. The C statistics of both markers for predicting the development of cardiovascular events were similar. Conclusions—Stiffness index β transformation of the baPWV may attenuate the significance of the baPWV as a risk marker for development of pathophysiological abnormalities related to cardiovascular disease in male subjects

A rare case of concomitant huge exophytic gastrointestinal stromal tumor of the stomach and Kasabach-Merritt phenomenon

<p>Abstract</p> <p>Background</p> <p>We report an extremely rare case of concomitant huge exophytic GIST of the stomach and Kasabach-Merritt phenomenon (KMP).</p> <p>Case presentation</p> <p>The patient was a 67-year-old man experiencing abdominal distension since September 2006. A physical examination revealed a 25 × 30 cm hard mass that was palpable in the middle and lower left abdomen minimal intrinsic mobility and massive ascites. Since the admitted patient was diagnosed with DIC, surgery could not be performed. The patient received a platelet transfusion and the DIC was treated. Due to this treatment, the platelet count recovered to 7.0 × 10⁴; tumor resection was performed at 16 days after admission. Laparotomy revealed a huge extraluminal tumor arising from the greater curvature of the stomach that measured 25 × 30 cm and had not ruptured into the peritoneal cavity or infiltrated other organs. Partial gastric resection was performed. The resected mass measured 25 × 25 × 20 cm. In cross section, the tumor appeared hard and homogenous with a small polycystic area. Histopathology of the resected specimen showed large spindle cell GIST with >5/50 HPF (high-power field) mitotic activity. The postoperative course was uneventful, and the coagulopathy improved rapidly.</p> <p>Conclusion</p> <p>Since the characteristic of tumor in this case was hypervascularity with bleeding and necrotic lesions, coagulopathy was thought to be caused by the trapping of platelets within a large vasculized tumor mass.</p

Prevalence and mechanism of fluoroquinolone resistance in clinical isolates of Proteus mirabilis in Japan

Fluoroquinolone (FQ) and cephalosporin (CEP) resistance among Enterobacteriaceae has been increasingly reported. FQ resistance occurs primarily through mutations in DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE). CEP resistance in Enterobacteriaceae is mainly due to the production of CTX-M type extended-spectrum β-lactamases. Although prevalence and mechanisms of FQ and CEP resistance in Enterobacteriaceae such as Escherichia coli have been well studied, little is known about Proteus mirabilis in Japan. In this study, we assessed the prevalence and mechanism of FQ resistance in Japanese clinical isolates of P. mirabilis. We collected 5845 P. mirabilis isolates from eight hospitals between 2000 and 2013. Prevalence of FQ resistance was calculated as the annual average percentage of all P. mirabilis isolates. We selected 50 isolates exhibiting susceptibility, intermediate resistance, or resistance to levofloxacin (LVX) and identified amino acid substitutions in GyrA, GyrB, ParC, and ParE. The prevalence of FQ-resistant P. mirabilis gradually increased from 2001 to 2004, reaching 16.6% in 2005, and has remained relatively high (13.3–17.5%) since then. Low-level LVX-resistant strains (MIC, 8–16 mg/L) showed significant changes in GyrB (S464Y or -I, or E466D). High-level LVX-resistant strains (MIC, 32–128 mg/L) displayed significant changes in GyrA (E87K) and ParE (D420N). The highest-level LVX-resistant strains (MIC, ≥ 256 mg/L) presented significant changes in GyrA (E87K or -G), GyrB (S464I or -F), and ParE (D420N). Our findings suggest that substitutions in GyrA (E87) and ParE (D420) have played an important role in the emergence of high-level LVX-resistant P. mirabilis isolates (MIC, ≥ 32 mg/L) in Japan