In vitro marginal and internal adaptation of metal-ceramic crowns with cobalt-chrome and titanium framework fabricated with CAD/CAM and casting technique.

AIM: The purpose of this study was to compare the marginal and internal fit of Co-Cr and titanium ceramic crowns fabricated with 2 different techniques: CAD/CAM milling and traditional casting (TC). MATERIALS AND METHODS: Ten traditional casting of Co-Cr (TCC), 10 CAD/CAM milling of Co-Cr (MC), 10 traditional casting of titanium (TCT), 10 CAD/CAM milling of titanium ceramic crowns (MT) were fabricated. Silicone replicas were obtained to measure internal gap volume, marginal gap and internal adaptation that was evaluated at 3 regions: axial wall, axio-occlusal angle, and occlusal surface. Measurements were made with a X-ray micro computerized tomography (micro-CT) and analyzed with Bonferroni and Dunnet T3 post-hoc tests (α = 0.05). RESULTS: One-way ANOVA revealed no statistically significant differences among the groups for measurements at the marginal gap (P > 0.05). At axial wall region the mean values of TCT group were higher than those of groups but only statistically not significant for TCC group (P < 0.05). TCC group statistically gives better results than MC group in axio-occlusal and occlusal regions (P < 0.05). The mean measurement of internal gap volume were 20.59 ± 0.83 mm3 for TCC, 22.73 ± 0.82 mm3 for MC, 22.83 ± 1.11 mm3 for TCT and 20.51 ± 1.16 mm3 for MT. Mean internal gap volume values MT group were smaller than those of groups but only statistically not significant for TCC group (P > 0.05). CONCLUSION: All groups performed similar marginal adaptation. The cement film thickness at axio-occlusal angle point and occlusal region were higher for MC crowns.

Green-diode-pumped femtosecond Ti:Sapphire laser with up to 450 mW average power.

We investigate power-scaling of green-diode-pumped Ti:Sapphire lasers in continuous-wave (CW) and mode-locked operation. In a first configuration with a total pump power of up to 2 W incident onto the crystal, we achieved a CW power of up to 440 mW and self-starting mode-locking with up to 200 mW average power in 68-fs pulses using semiconductor saturable absorber mirror (SESAM) as saturable absorber. In a second configuration with up to 3 W of pump power incident onto the crystal, we achieved up to 650 mW in CW operation and up to 450 mW in 58-fs pulses using Kerr-lens mode-locking (KLM). The shortest pulse duration was 39 fs, which was achieved at 350 mW average power using KLM. The mode-locked laser generates a pulse train at repetition rates around 400 MHz. No complex cooling system is required: neither the SESAM nor the Ti:Sapphire crystal is actively cooled, only air cooling is applied to the pump diodes using a small fan. Because of mass production for laser displays, we expect that prices for green laser diodes will become very favorable in the near future, opening the door for low-cost Ti:Sapphire lasers. This will be highly attractive for potential mass applications such as biomedical imaging and sensing.

Non-invasive fibrosis tests are correlated with necroinflammatory actvity of liver in patients with chronic hepatitis B.

BACKGROUND: The gold standarda method used for assessing necroinflammatory activity and fibrosis in the liver is a liver biopsy which has many disadvantages. Therefore, many investigators have been trying to develop non-invasive tests for predicting liver fibrosis score (LFS) of these patients. The aim of this study is to describe the relationship between certain non-invasive fibrosis markers with LFS and histological activity index (HAI) detected histopathologically by liver biopsy in chronic hepatitis B patients. MATERIALS AND METHODS: A total of 54 patients who had undergone a liver biopsy with the diagnosis of chronic HBV infection were included in the study. Ishak scoring was used for the evaluation of liver fibrosis, and a modified Knodell HAI was used for demonstration of necroinflammation. In this study, non-invasive fibrosis tests were calculated as described in previous studies. RESULTS: Histological acitivity index was positively correlated with age, age/platelet index, cirrhosis discriminant score (CDS), AST/platelet ratio index (APRI), AST/platelet/GGT/AFP index (APGA), fibro-quotient (Fibro-Q), Goteburg University Cirrhosis Index (Guci), and Platelet/Age/Phosphatase/AFP/AST index (PAPAS). When divided into two groups according to HAI, Guci and APGA were found significantly different both in >4 and >4 HAI groups than the other group. In ROC analysis performed for LFS; PAPAS, APGA, FFI and APRI were the markers having the highest AUC levels, and in ROC analysis performed for HAI; Guci, APRI and APGA were the markers with the highest AUC levels. CONCLUSIONS: APRI, APGA and GUCI tests may be helpful in prediction of necroinflammatory scores in the liver.

1 mJ pulse bursts from a Yb-doped fiber amplifier.

We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier capable of generating 60 µJ pulses within bursts of 11 pulses with extremely uniform energy distribution facilitated by a novel feedback mechanism shaping the seed of the burst-mode amplifier. The burst energy can be scaled up to 1 mJ, comprising 25 pulses with 40 µJ average individual energy. The amplifier is synchronously pulse pumped to minimize amplified spontaneous emission between the bursts. Pulse propagation is entirely in fiber and fiber-integrated components until the grating compressor, which allows for highly robust operation. The burst repetition rate is set to 1 kHz and spacing between individual pulses is 10 ns. The 40 µJ pulses are externally compressible to a full width at half-maximum of 600 fs. However, due to the substantial pedestal of the compressed pulses, the effective pulse duration is longer, estimated to be 1.2 ps.

Two maxillary lesions containing bony/calcified shells.

Because of the close anatomical relationship between the maxillary sinus and the adjacent dental region, determining the primary site of cysts in these regions can be a diagnostic dilemma. In this article, two cases with similar radiological findings are presented. These cases had lesions involving the maxillary sinus and the adjacent alveolar process; the lesions were surrounded with egg-shaped, linear opacities. Diagnoses of a residual radicular cyst in one case and a calcified mucocoele (which is very rare) in the other case were predicted with the help of radiological findings and were confirmed surgically and histopathologically.

Geniculo-temporo-parotideal neurofibroma of the facial nerve. A case report.

Preoperative diagnosis of facial nerve neurofibroma is difficult when it presents as an asymptomatic parotideal mass. Facial nerve tumor suspicion arises during parotid surgery, histopathologic evaluation confirms diagnosis and postoperative imaging demonstrates a nerve tumor and its extension. We present the multimodality imaging findings of a 43-year-old man with a solitary neurofibroma involving the whole facial nerve continuously from geniculate ganglion to parotideal segment as the first case in the literature.

Renal infarct: contrast-enhanced power Doppler sonographic findings.

Power Doppler sonography (PDUS) is a promising technique for the diagnosis of renal infarcts. PDUS's efficacy may be enhanced by using sonographic contrast agents. We evaluated 3 cases of renal infarction using PDUS and the sonographic contrast agent Levovist. The findings were compared with those of other imaging modalities, such as scintigraphy, CT, and angiography. In case 1, PDUS showed a patent interlobar artery only in the lower part of the right kidney and no other perfusion of the right renal parenchyma. Contrast-enhanced PDUS showed patchy areas of preserved perfusion in the lower and middle-upper anterior portions of the kidney. In case 2, PDUS showed diffuse and patchy perfusion defects in the anterolateral portion of the right kidney. On contrast-enhanced PDUS, no signal enhancement was seen in these areas, but the perfusion defects were better delineated. In case 3, PDUS showed no perfusion in the upper pole of the kidney; the nonperfused area extended to the posterior upper portion of the kidney but could not be distinguished from normal tissue. After injection of the contrast agent, there was no enhancement of the posterior extension of the upper pole infarct, but Doppler signals from the surrounding normal parenchyma were enhanced, so the area was more clearly demarcated. The administration of the contrast agent facilitated the visualization of the infarcts in all 3 cases.