Does the menstrual phase affect gastric emptying? Prospective, observational study.

OBJECTIVE: Pulmonary aspiration of gastric content is a serious complication of anesthesia. It is unclear what effects different parts of the menstrual cycle have on how long it takes for the stomach to empty. This prospective observational study assessed the relationship between menstrual cycle phases and gastric emptying using ultrasonography (USG) in volunteers of reproductive age. PATIENTS AND METHODS: Between days 8-10 of the menstrual cycle in the follicular phase and days 18-20 of the luteal phase, a total of 24 healthy volunteers received four stomach USG procedures. In both phases, the gastric antrum was evaluated with USG in the right lateral decubitus position after fasting for 10 hours, followed by 2 hours of fasting after liquid intake and 6 hours of fasting after solid food intake. The gastric content, gastric antrum area, and estimated gastric volume determined whether the stomach was full or empty. RESULTS: A full stomach was detected in 8 (8.3%) out of 96 measurements performed on the volunteers. After liquid food intake, a full stomach was detected in 2 subjects in the luteal phase, while all the subjects had an empty stomach during the follicular phase (p=0.500). After solid food intake, a full stomach was detected in 6 subjects in the luteal phase, and again, all subjects had an empty stomach during the follicular phase (p=0.031). CONCLUSIONS: Ultrasound assessment of gastric volume in volunteers of reproductive age has shown that gastric emptying of solid foods is slowed during the luteal phase of the menstrual cycle.

Twenty-Four-Month Clinical Comparison of Two Bulk-Fill and a Microhybrid Composite Restorations in Class II Cavities.

OBJECTIVES: The aim of this study was to evaluate the clinical performance of two bulk-fill composite resins in Class II cavities for up to twenty-four months. MATERIALS AND METHODS: In total 75 Class II restorations were made in 25 patients using two nanohybrid bulk-fill resin composites and a microhybrid composite. The restorations were evaluated at baseline and at 6, 12, and 24 months, using U.S. Public Health Service (USPHS) criteria. The restoration groups were compared using the Pearson chi-square test, and the Cochran Q-test was used to compare the changes across different time points within restorative materials (p⟨0.05). RESULTS: Two patients who did not attend the appointments were excluded from the study, so 23 patients were evaluated with a 92% recall rate; at the end of the two-year follow-up, 66 restorations were evaluated. Three restorations underwent endodontic treatment and were deemed failures. The overall success rate was 96%. There were statistically significant differences between the three restorative resins in terms of color match parameter (p⟨0.05). No differences were observed between the restorative resins in terms of other criteria (p⟩0.05). CONCLUSIONS: During the two-year follow-up period, the three composite resins showed similar clinical performance except for the color match parameter.

Evaluation of biochemical changes in dental tissues after different office bleaching methods.

The color of the teeth is an important topic for many people and can be influenced by intrinsic and extrinsic stains. There is an increasing demand for whitening of the teeth year by year. The most popular way of whitening is "bleaching," which is the result of the breakdown of pigments located in the enamel and/or the dentin, caused by reactive oxygen species (ROS) released from bleaching agents. These bleaching agents could increase matrix metalloproteinase (MMP)-mediated collagen degradation in dentin. The aim of this study was to compare biochemical changes and oxidative stress levels of the human premolar dentin-pulp complex after three different bleaching methods containing hydrogen peroxide (H2O2) bleaching agents. Individuals, whose first four premolars were extracted for orthodontic purposes, included into the study. Group 1-Laser: bleaching gel containing 46% H2O2 (LaserWhite20 whitening gel, Biolase Technology Inc., San Clemente, CA, USA) and a diode laser activation (Ezlase 940 nm system). Group 2: 35% H2O2 containing whitening gel (Whiteness HP Maxx, FGM) and halogen light source activation (Optilux 501, Kerr, Orange, CA, USA). Group 3: 35% H2O2 containing whitening gel (Whiteness HP Maxx, FGM). Group 4-Control: No whitening treatment. According to the test results, there were no significant differences among groups in the values of cathepsin B and MMP proteolytic activities ( p > 0.05). The total ROS values released from the dentin tissue were higher than those obtained from the pulp tissue ( p < 0.05). There were significant differences among the bleaching groups in the ROS values released from the dentin tissue.

Temperature increases on the external root surface during endodontic treatment using single file systems.

AIMS: The aim of this study is to evaluate increases in temperature on the external root surface during endodontic treatment with different rotary systems. MATERIALS AND METHODS: Fifty human mandibular incisors with a single root canal were selected. All root canals were instrumented using a size 20 Hedstrom file, and the canals were irrigated with 5% sodium hypochlorite solution. The samples were randomly divided into the following three groups of 15 teeth: Group 1: The OneShape Endodontic File no.: 25; Group 2: The Reciproc Endodontic File no.: 25; Group 3: The WaveOne Endodontic File no.: 25. During the preparation, the temperature changes were measured in the middle third of the roots using a noncontact infrared thermometer. The temperature data were transferred from the thermometer to the computer and were observed graphically. Statistical analysis was performed using the Kruskal-Wallis analysis of variance at a significance level of 0.05. RESULTS: The increases in temperature caused by the OneShape file system were lower than those of the other files (P < 0.05). The WaveOne file showed the highest temperature increases. However, there were no significant differences between the Reciproc and WaveOne files. CONCLUSIONS: The single file rotary systems used in this study may be recommended for clinical use.

Effect of a re-wetting agent on bond strength of an adhesive to primary and permanent teeth dentin after different etching techniques.

OBJECTIVE: This study investigated the effect of a re-wetting agent on the microtensile bond strengths (mTBS) of primary and permanent dentin after acid or laser etching. MATERIALS AND METHODS: Twelve permanent and 12 primary molar teeth were ground to expose an occlusal dentin surface. Each group teeth were randomly divided into groups; I-II: 37% phosphoric acid etching with/without re-wetting agent, III-IV: Erbium: Yttrium aluminium garnet laser etching with/without re-wetting agent. An etch-and-rinse adhesive was used, and vertical sticks were obtained for the microtensile test. RESULTS: mTBS of permanent teeth was higher than that of primary teeth (P < 0.05). Re-wetting agent groups were similar with control groups in both etching groups in the permanent teeth (P > 0.05). Re-wetting agent group was similar with the control group in acid etch group (P > 0.05) and lower than the control group in laser etch group in primary teeth (P < 0.05). CONCLUSION: Acid etching in permanent teeth; laser etching in primary teeth was found more successful. The use of re-wetting agent did not provide an advance on bond strength of the adhesive in both primary and permanent teeth after acid-etch or laser-etch.

Human brain mercury levels related to exposure to amalgam fillings.

The safety of dental amalgam as the primary material in dental restoration treatments has been debated since its introduction. It is widely accepted that amalgam restorations continuously release elemental mercury (Hg) vapor, which is inhaled and absorbed by the body and distributed to tissues, including the brain. The aim of the present study was to investigate whether the presence of amalgam fillings is correlated with brain Hg level. The Hg levels in the parietal lobes of the brains of 32 cadavers were analyzed with an atomic absorption spectrometer with the mercury hydride system. A total of 32 brain samples were tested; of these, 10 were from cadavers with amalgam fillings, while 22 of them were amalgam free. Hg was detected in 60.0% (6 of 10) of the samples in the amalgam group and in 36.3% (8 of 22) in the amalgam-free group. The average Hg level of the amalgam group was 0.97 ± 0.83 µg/g (minimum: 0.3 µg/g and maximum: 2.34 µg/g), and in the amalgam-free group, it was 1.06 ± 0.57 µg/g (minimum: 0.17 µg/g and maximum: 1.76 µg/g). The results of the present study showed no correlation between the presence of amalgam fillings and brain Hg level.

Evaluation of micro-tensile bond strength of caries-affected human dentine after three different caries removal techniques.

OBJECTIVE: This study evaluated the effect that different techniques for removing dental caries had on the strength of the microtensile bond to caries-affected human dentine created by three bonding agents. MATERIALS AND METHODS: Forty-five human molar teeth containing carious lesions were randomly divided into three groups according to the technique that would be used to remove the caries: a conventional bur, an Er:YAG laser or a chemo-mechanical Carisolv(®) gel (n=15). Next, each of the three removal-technique groups was divided into three subgroups according to the bonding agents that would be used: Clearfil(®) SE Bond, G-Bond(®), or Adper(®) Single Bond 2 (n=5). Three 1mm(2) stick-shaped microtensile specimens from each tooth were prepared with a slow-speed diamond saw sectioning machine fitted with a diamond-rim blade (n=15 specimens). For each removal technique one dentine sample was analysed using scanning electron microscopy. RESULTS: There were statistically significant differences in the resulting tensile strength of the bond among the techniques used to remove the caries and there were also statistically significant differences in the strength of the bond among the adhesive systems used. The etch-and-rinse adhesive system was the most affected by the technique used to remove the caries; of the three techniques tested, the chemo-mechanical removal technique worked best with the two-step self etch adhesive system. CONCLUSION: The bond strength values of the etch-and-rinse adhesive system were affected by the caries removal techniques used in the present study. However, in the one- and two-step self etch adhesive systems, bond strength values were not affected by the caries removal techniques applied. While a chemo-mechanical caries removal technique, similar to Carisolv(®), may be suggested with self etch adhesive systems, in caries removal techniques with laser, etch-and-rinse systems might be preferred. CLINICAL SIGNIFICANCE: Caries removal methods may lead to differences in the characteristics of dentine surface. Dentine ultra structure generally affects the bonding of adhesive materials commonly used in restorative dentistry. Whereas etch-and-rinse system, like the ones used in the present study, are affected by these changes, the self etch systems are not affected. Hence, clinicians may opt for caries removal methods and systems appropriate for each patient and practice.

Susceptibility-weighted imaging in migraine with aura.

We report 2 patients with migraine with aura, in whom SWI showed transient prominence of the venous vasculature within areas of impaired perfusion. The findings resolved spontaneously in both patients. This imaging technique may play a helpful role in assessing the vascular events in migraine with aura.

Diffusion weighted MR imaging in non-infarct lesions of the brain.

Diffusion weighted imaging (DWI) is a relatively new method in which the images are formed by the contrast produced by the random microscopic motion of water molecules in different tissues. Although DWI has been tried for different organ systems, it has been found its primary use in the central nervous system. The most widely used clinical application is in the detection of hyperacute infarcts and the differentiation of acute or subacute infarction from chronic infarction. Recently DWI has been applied to various other cerebral diseases. In this pictorial paper the authors demonstrated different DWI patterns of non-infarct lesions of the brain which are hyperintense in the diffusion trace image, such as infectious, neoplastic and demyelinating diseases, encephalopathies - including hypoxic-ischemic, hypertensive, eclamptic, toxic, metabolic and mitochondrial encephalopathies - leukodystrophies, vasculitis and vasculopathies, hemorrhage and trauma.

Atypical MRI findings in Canavan disease: a patient with a mild course.

Canavan disease is a severe, progressive leukodystrophy with an autosomal recessive inheritance, caused by aspartoacylase (ASPA) deficiency. The characteristic MRI features include diffuse, symmetrical white matter degeneration in the subcortical areas, with bilateral involvement of the globus pallidus. Proton magnetic resonance spectroscopy of the brain shows an increase in the concentration of N-acetylaspartic acid (NAA). The altered NAA metabolism has been traced to mutations in the gene encoding ASPA, located on chromosome 17 (17p13-ter). We present here a patient with a mild form of Canavan disease confirmed with the absent ASPA activity, atypical MRI findings, related to compound heterozygosity for a missense mutation, p.Tyr288Cys, and the known pan-European mutation, the p.Ala305Glu.

Spontaneous involution of a non-optic astrocytoma in neurofibromatosis type I: serial magnetic resonance imaging evaluation.

A patient with neurofibromatosis type I (NF1) was followed-up with serial magnetic resonance imaging (MRI) studies over a period of 6 years. A contrast-enhancing lesion of the internal capsule, histologically proven to be pilocytic astrocytoma through stereotactic brain biopsy with mass effect and associated edema, was detected to reveal spontaneous involution on follow-up MRI studies. Although spontaneous regression of gliomas of the optic pathway-hypothalamus in patients with NF1 is relatively common in the literature, spontaneous involution of non-optic (i.e. areas other than optic pathways and hypothalamus) gliomas is rarely reported. Conservative management with follow-up MRI studies should be considered for non-optic glial tumors and tumor-like masses in patients with NF1, and surgical treatment should not be considered unless the lesions exhibit a rapid or unrelenting growth on serial MRI studies or produce significant clinical deterioration.

Baló's concentric sclerosis: clinical and radiologic features of five cases.

Baló's concentric sclerosis (BCS) is a rare demyelinating disease considered to be a variant of multiple sclerosis. Five BCS cases were diagnosed antemortem based on their typical concentric mass patterns on MR images and based on clinical and CSF findings. Histopathologic investigation was also performed in one case. Our case report supports the concept that BCS may be a self-limited disease that is not always fatal. Characteristic MR imaging findings may allow antemortem diagnosis of BCS when performed at the onset of the disease.

Spinal ganglioneuroma presenting as a highly vascular lesion with hypertrophic venous drainage.

We present the case of a 33-year-old man with a highly vascular spinal ganglioneuroma associated with hypertrophic draining veins mimicking arteriovenous malformation. Ganglioneuromas are classically known as avascular and association with hypertrohic venous drainage has not been previously reported. The magnetic resonance imaging and digital subtraction angiography features of this benign tumor were strongly suspicious for malignancy because of the high vascularity caused by intratumoral arteriovenous shunts. This case emphasizes the importance of including ganglioneuroma in the differential diagnosis of vascular spinal tumors and recalls that hypertrophic draining veins may be associated with spinal tumors.

Inflammation of vertebral bone associated with acute calcific tendinitis of the longus colli muscle.

We present a case of acute retropharyngeal calcific tendinitis with characteristic findings on radiographic, computed tomography, and magnetic resonance imaging (MRI). To our knowledge, this is the first acute retropharyngeal calcific tendinitis report having inflammation of both the vertebra itself and the longus colli muscle diagnosed on MRI. In patients with neck pain, acute retropharyngeal calcific tendinitis should be kept in mind in the differential diagnosis, even if these patients had vertebral pathological signals on MRI.

High intensity signal of the posterior pituitary. A study with horizontal direction of frequency-encoding and fat suppression MR techniques.

PURPOSE: To evaluate the consistency of fat in the high intensity signals of the normal neurohypophysis and to differentiate the high signal of posterior pituitary from that of dorsum sella. Sagittal SE T1-weighted images with frequency encoding in the horizontal direction were used in order to differentiate the high signal of posterior pituitary and dorsum sella by the vertically-oriented chemical shift artifact. MATERIAL AND METHODS: The sellae of 46 normal volunteers were imaged with a commercially available fat suppression technique and SE sequences with frequency encoding in vertical (25 cases) and horizontal (21 cases) axes. RESULTS: The high signal intensity was absent in 9% of the normal volunteers with no predilection to any specific age group. None of the cases with posterior pituitary high intensity signals showed suppression of the signal with fat suppression technique. A fat suppression technique was helpful in documenting the hyperintensity in 7% of normal volunteers. Nineteen of the 21 (90%) cases with high signal intensity were detected by routine SE T1-weighted images, whereas 18 of the 19 (95%) cases were detected by imaging with frequency encoding in the horizontal direction. CONCLUSION: The high signal does not indicate the presence of fat. Fat suppression technique and a horizontal direction of frequency encoding help in differentiating the high signal of the neurohypophysis from that of dorsum sella.