In vitro effects of different moisture level and curing method on microleakage of resin cements to pulp chamber dentine.

This study evaluated the microleakage of resin cements in the pulp chamber dentin. Fifty specimens of sound human molars were divided into five groups. Composite cores cemented using Clearfil SA Luting in the first group to a dried dentin and in the second group to a moistened dentin and then light-cured. In third and fourth groups, cement was placed on dried and moistened dentin and self-cured respectively. In fifth group, composite cores were cemented by Panavia F2.0. After thermocycling, microleakage was evaluated using fluid filtration technique. The highest microleakage mean value was observed in the group with light-cured to a dry dentin. The mode of curing in contrast to moisture value had significant effect on microleakage. The microleakage of self- adhesive resin cement used in this study was lower in case of self cured than in case of light-cured and was not related to the dentin surface moisture.

The clinical effectiveness of various adhesive systems: an 18-month evaluation.

The aim of this clinical trial was to compare the clinical performance of three different adhesive systems over 18 months in noncarious cervical lesions (NCCLs). Thirty patients, with at least three noncarious cervical lesions, were enrolled in the study. One operator randomly restored a total of 90 lesions with resin composite (Herculite XRV). The restorations were bonded with either Optibond FL (OF), three-step total-etch; Optibond Solo Plus (OS), two-step total-etch; or Optibond All-In-One (OA), one step self-etch. The restorations were clinically evaluated at baseline and after six, 12, and 18 months using the eight United States Public Health Services criteria. Data were analyzed using Friedman and Wilcoxon signed ranks tests (p<0.05). After 18 months, the retention rate was (OF) 96.5%, (OS) 93.1%, and (OA) 89.7%. Differences among the three adhesive systems for evaluated criteria were not observed in comparison of the mean Alfa score percentages. There was a significant increase in marginal discoloration for (OA) adhesive after 18 months compared with baseline (p=0.011). Other restoration criteria had no statistically significant differences among the three adhesives (p>0.05). With the exception of marginal discoloration, the clinical effectiveness of three types of adhesive systems in NCCLs was acceptable after 18 months. However, using the one-step self-etch adhesive may lead to some marginal discolorations.

In vitro effects of several surface preparation methods on shear bond strength of orthodontic brackets to caries-like lesions of enamel.

AIM: The aim of this study was to evaluate the efficiency of several surface preparation methods for improving shear bond strength of brackets to demineralised enamel. STUDY DESIGN: in vitro study. Eighty premolars were selected and divided into 5 groups. Group 1 served as the control, while the remaining 4 groups were immersed in a demineralising solution (pH 4.8) for 12 weeks. In groups 1 (control) and 2 (demineralised/control) conventional acid etching was used. In group 3, a solution of 5% sodium hypochlorite (NaOCl) was applied on enamel surface for one minute after acid etching. The brackets in group 4 were bonded with Transbond Plus self-etching primer, and group 5 underwent treatment with a 2% sodium fluoride (NaF) gel, which was applied on the enamel surface for 4 minutes before etching. Shear bond strength (SBS) and adhesive remnant index (ARI) were determined in all groups, and surface morphology was examined under scanning electron microscope (SEM). RESULTS: The mean SBS of acid-etched demineralised enamel was significantly lower than that of acid-etched sound enamel (p<0.05). Treatment of caries-like lesions with 5% NaOCl or self-etching primer failed to improve the bond strength. After NaF treatment and acid etching of demineralised enamel, both type 1 and type 2 etching patterns were observed and the resulting SBS was comparable to that of sound enamel (p>0.05). CONCLUSION: The application of 2% NaF on enamel caries before bracket bonding is an effective way for enhancing the bond strength.

Neuro-Behcet's disease: a masquerader of multiple sclerosis. A prospective study of neurologic manifestations of Behcet's disease in 96 Iranian patients.

Behcet's disease is a multisystem vasculitis. Its neurologic complications include different syndromes. The purpose of this investigation was to study the prevalence of neurologic manifestations among patients with Behcet's disease and to determine the frequency of different symptoms, signs, and syndromes in neuro-Behcet's disease. Ninety-six consecutive patients who were referred to the Behcet's Disease Clinic in Shiraz (southern Iran) were interviewed and thoroughly examined. Psychiatric evaluation, CSF analysis, electroencephalography, electrodiagnostic studies, and neuroradiologic imaging (preferably MRI) were performed in appropriate cases. Six patients (6.3%) had definite neuro-Behcet's disease. They were 4 males and 2 females (mean age 37.5 years). In 2 patients Behcet's disease had not been diagnosed before. The most frequent symptoms of neuro-Behcet's disease were headache (83.3%), paresthesia (83.3%), unsteadiness (66.7%), diplopia (66.7%), and weakness (50%). The most frequent signs were gait abnormalities (66.7%), sensory abnormalities (66.7%), ophthalmoplegia (50%), cerebellar ataxia (50%), and hemiplegia (50%). The most common syndrome was brain-stem+ type (50%). Subacute onset and relapsing-remitting course were the most common temporal patterns. Neurological manifestation is a relatively less frequent complication of Behcet's disease but it produces severe disabilities. It must be considered in differential diagnosis of multiple sclerosis.

A multireflection cell for enhanced absorbance detection in microchip-based capillary electrophoresis devices.

The design, fabrication and testing of a photolithographically fabricated, glass-based multireflection absorbance cell for microfluidic devices, in particular microchip-based capillary electrophoresis (CE) systems is described. A multireflection cell was fabricated lithographically using a three-mask process to pattern aluminum mirrors above and below a flow channel in a chip, with 30 microm diameter optical entrance or exit apertures (one in each mirror) positioned 200 microm apart. Source and detector were positioned on opposite sides, and the metal mirrors were made 1 cm square, to reduce stray light effects. Calibration curves using bromothymol blue (BTB) with a 633 nm source (He:Ne laser) were linear to at least 0.5 absorbance units, with typical r2 values of 0.9997, relative standard deviations in the slopes of +/- 1.3%, and intercepts of zero within experimental error. Effective optical pathlengths of 50-272 microm were achieved, compared to single-pass pathlengths of 10-30 microm, corresponding to sensitivity enhancements (i.e., optical path length increase) of 5 to 10-fold over single-pass devices. Baseline absorbance noise varied within a factor of two in almost all devices, depending only weakly on path length. This device can give much higher absorbance sensitivity, and should be much easier to manufacture than planar, glass-based devices previously reported.

Postcontrast MRI of cranial meninges: leptomeningitis versus pachymeningitis.

OBJECTIVE: Our goal was to characterize the patterns of meningeal enhancement in postcontrast MR images and correlate these patterns with the clinical disorders. MATERIALS AND METHODS: The MR scans, medical records, and laboratory findings of 83 patients, whose postcontrast MR studies of the head demonstrated meningeal enhancement, were reviewed retrospectively. The patterns of enhancement of the different layers of the meninges were divided into two types: leptomeningeal (pia and arachnoid), when enhancement of the meninges followed the convolutions of the gyri and/or involved the meninges around the basal cisterns; and pachymeningeal (dura), when the enhancement was thick and linear or nodular along the inner surface of the calvarium, falx, or tentorium without extension into the cortical gyri or basal cistern involvement. Enhancement around the basal cistern was considered leptomeningeal, since the dura-arachnoid is widely separated from the pia-arachnoid in this region. Further, the meningeal enhancement was divided into five etiologic subgroups, i.e., carcinomatous, infectious, inflammatory, reactive, and chemical. The medical history, clinical presentation, and findings on CSF analysis were used to distinguish infectious from carcinomatous meningitis. Meningeal enhancement due to surgery, shunt, or trauma was considered reactive, while ruptured cysts (dermoid or cysticercoid) or intrathecal chemotherapy were classified as chemical meningitis. Meningitis secondary to involvement by collagen vascular disease or sarcoidosis was considered to be inflammatory. RESULTS: Thirty of the 83 subjects had carcinomatous, 28 infectious, 14 reactive, 8 chemical, and 3 inflammatory etiology for meningitis. Twenty-five cases (83%) of the carcinomatous, 14 (100%) of the reactive, 3 (100%) of the inflammatory, and 1 (12%) of the chemical meningitis subgroups demonstrated pachymeningeal enhancement, while 28 cases (100%) of the infectious meningitis and 7 (78%) of the chemical meningitis subgroups had leptomeningeal enhancement. Only five cases (17%) of the carcinomatous meningitis subgroup showed leptomeningeal enhancement. Four of these five cases were as a result of direct spread of intraparenchymal tumors or through perineural extension, rather than hematogenous involvement. Only one patient with carcinomatous meningitis demonstrated leptomeningeal enhancement without clear intraparenchymal lesion. CONCLUSION: The recognition of various patterns of meningeal enhancement (leptomeningitis versus pachymeningitis) may help in differentiating between infectious and carcinomatous meningitis. This study demonstrated that infectious meningitis presents mostly as leptomeningitis, while carcinomatous meningitis presents as pachymeningitis.

Plastic-embedded human marrow biopsy specimens: improved histochemical methods.

Improved methods for processing, sectioning, and staining plastic (glycol methacrylate)-embedded human marrow biopsy specimens were studied. Special stains, including naphthol AS-D-chloro-acetate esterase, PAS, reticulin, and iron, have been modified so that they are suitable for undecalcified, 2-microns-thick, plastic-embedded human marrow biopsy specimens. These adaptations permit plastic-embedded marrow specimens to be used for clinical diagnosis. Marrow biopsy specimens embedded in plastic were compared with biopsy specimens preserved by the conventional paraffin method. The plastic-embedded marrows provide better results from morphologic examination (enhancing diagnostic accuracy), permit assessment of bone as well as of marrow, and allow histochemical analysis to be performed.

Response of pulmonary veins to increased intracranial pressure and pulmonary air embolization.

Brain compression with subdural air causes pulmonary hypertension and noncardiogenic pulmonary edema (A. B. Malik, J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 42: 335-343, 1977). To see whether air emboli to the lungs rather than brain compression caused these findings, anesthetized dogs received intravenous air infusions, subdural air infusions, or brain compression from balloons inflated in the subdural space. Subdural air and intravenous air resulted in similar vascular responses. Pulmonary artery pressure (Ppa) increased 160% (P less than 0.01) and pulmonary venous pressure transiently rose 13 +/- 5 Torr (P less than 0.05) without an increase in left atrial pressure or cardiac output (Q). The end-tidal PCO2 fell 55% (P less than 0.01) and the postmortem weight of the lungs increased 55% (P less than 0.05). Brain compression with a subdural balloon instead of air only caused a 20% rise in Ppa and Q without pulmonary edema. Thus, pulmonary air emboli rather than brain compression accounts for the edema and pulmonary hypertension caused by subdural air. Catheters in pulmonary veins and the left atrium showed that air emboli cause transient pulmonary venous hypertension as well as a reproducible form of noncardiogenic pulmonary endema.

Malignant adenolymphoma.

Adenolymphoma (Warthin's tumor) is a well studied benign tumor of the salivary gland. Malignant transformation of such a tumor is rare and not well documented in the literature. The light microscopic and ultrastructural features of an undifferentiated carcinoma arising in an adenolymphoma in the parotid gland of a middle aged male are described, and the relevant literature is reviewed. Similarities between the benign adenolymphoma and the undifferentiated malignant tumor, such as the presence of interstitial lymphoplasmacytic cell infiltrates, dark and light epithelial cells, similar cytoplasmic organelles, and nuclear morphology, suggest a malignant transformation of a previously existing benign adenolymphoma.