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SUMMARY Objective The aim of the present in vitro study was to examine the caries-inhibiting effect of a pit and fissure sealant (PFS) containing ion-releasing microcapsules under cariogenic conditions in a biofilm artificial mouth. Methods and Materials Forty-eight human third molars were divided into four groups (n=12 per group). Fissures were extended with burs and sealed with experimental PFS. The four groups of specimens were treated as follows: 1) EPFS 1: EPFS (Premier Dental) of increasing viscosity, containing microcapsules loaded with remineralizing agents (calcium, phosphate, and fluoride ions); 2) US: fluoride-releasing PFS (UltraSeal XT plus, UltraDent Products, South Jordan, UT, USA); 3) EPFS 2: experimental PFS of constant viscosity containing microcapsules loaded with calcium, phosphate, and fluoride ions; and 4) FT: glass ionomer cement (GIC) (GC Fuji Triage CAPSULE WHITE glass ionomer cement, GC Europe NV, Leuven, Belgium). FT and US were used as control groups. EPFS 1 and EPFS 2 were the experimental groups. Specimens were stored in distilled water for 14 days at 37°C, subjected to 10,000 thermocycles (5°C and 55°C) and finally exposed to microbiological cycling in a Streptococcus mutans-based artificial mouth for 10 days. Replicas were made for scanning electron microscopic (SEM) evaluation and specimens were cut for fluorescence microscopy. Results Overall demineralization depths at the margin of Fuji Triage were significantly shallower than in the other groups (p Conclusions The experimental PFS with microcapsules containing active components for remineralization did not show a caries-inhibiting effect compared to a fluoride-releasing resin-based PFS. Lower demineralization depths adjacent to GIC sealants indicate an anticariogenic effect through fluoride ion release.

Objective Beyond static assessment, functional techniques are increasingly applied in magnetic resonance imaging (MRI) studies. Stress MRI techniques bring together MRI and mechanical loading to study knee joint and tissue functionality, yet prototypical axial compressive loading devices are bulky and complex to operate. This study aimed to design and validate an MRI-compatible pressure-controlled varus–valgus loading device that applies loading along the joint line. Methods Following the device’s thorough validation, we demonstrated proof of concept by subjecting a structurally intact human cadaveric knee joint to serial imaging in unloaded and loaded configurations, i.e. to varus and valgus loading at 7.5 kPa (= 73.5 N), 15 kPa (= 147.1 N), and 22.5 kPa (= 220.6 N). Following clinical standard (PDw fs) and high-resolution 3D water-selective cartilage (WATSc) sequences, we performed manual segmentations and computations of morphometric cartilage measures. We used CT and radiography (to quantify joint space widths) and histology and biomechanics (to assess tissue quality) as references. Results We found (sub)regional decreases in cartilage volume, thickness, and mean joint space widths reflective of areal pressurization of the medial and lateral femorotibial compartments. Discussion Once substantiated by larger sample sizes, varus–valgus loading may provide a powerful alternative stress MRI technique.

The aim of this systematic review was to evaluate the clinical outcome of partial pulpotomy, pulpotomy and pulpectomy for treating primary teeth with normal or infected pulp or with irreversible pulpitis.Two reviewers on Pubmed and ISI Web of Science performed a comprehensive literature review of publications from 1966 until July 2019. Pico outline was used to facilitate literature research. Among abstracts, publications were selected according to the following criteria: prospective clinical study, correct indication for the performed treatment, clear definition of clinical and/or radiographic success criteria and at least 6-month follow-up period. The strict selection criteria under the keywords "pulpotomy", "partial pulpotomy" and "pulpectomy" resulted in a limited amount of randomised controlled trials (RCT) or controlled clinical trials (CT). Qualitative assessment of the selected clinical studies and level of evidence was included according to the criteria described by the Oxford Centre for Evidence-Based Medicine (CEBM).Prerequisites for a successful pulpotomy are symptom-free teeth, sterile removal of coronal pulp and haemostasis. Both MTA and formocresol perform well for partial pulpotomies after caries exposure. Formocresol had been the most popular amputation material for pulpotomies. Due to the potential side effects, other medicaments, such as ferric sulfate, mineral trioxide aggregate (MTA) or NaOCl are suggested. Grey and white MTA yeld the same results. Lasers are not recommended due to their large diversity. Regarding pulpectomy, the conditions, procedures, and evaluation for the treatment were not well defined in the studies. Nevertheless, there is evidence to use calcium hydroxide, zinc oxide eugenol paste or iodoform based pastes as root filling materials for non-vital molars. Pulpectomies showed better success rates than pulpotomies. Stainless steel crowns are recommended as definite restorations after both endodontic treatments. Longer follow-up periods, further clinical studies with comparable conditions and clear definition of evaluation criteria are needed to further confirm the results of endodontic treatment in primary teeth.

Purpose To systematically review the clinical performance of restorative materials after pulp therapy of carious primary teeth. It is part 2 of a systematic review on the clinical effectiveness of restorative materials for the management of carious primary teeth supporting the European Academy of Paediatric Dentistry (EAPD) guideline development. Methods Four electronic databases were systematically searched up to December 28th, 2020. Randomised controlled clinical trials (RCTs) on restorative materials for the restoration of carious primary teeth after pulp therapy were included. Failure rate, annual failure rate (AFR) and reasons for failure were recorded. Studies were sorted by restorative materials. The Cochrane Risk of bias tool for randomised trials (RoB 2.0) was used for quality assessment. Results After identification of 1685 articles and screening of 41 papers from EAPD review group 1, 5 RCTs were included. Restored primary molars with pulpotomy presented the following AFRs: composite resin (CR) 0%, preformed metal crowns (PMCs) 2.4–2.5%, resin-modified glass-ionomer cement combined with CR 3.8%, compomer 8.9%, and amalgam 14.3%. Maxillary primary incisors receiving pulpectomy exhibited AFRs of 0–2.3% for composite strip crowns (CSCs) depending on the post chosen. Reasons for failure were secondary caries, poor marginal adaptation, loss of retention and fracture of restoration. All studies were classified as high risk of bias. Meta-analyses were not feasible given the clinical/methodological heterogeneity amongst studies. Conclusion Considering any limitations of this review, CR and PMCs can be recommended for primary molars after pulpotomy, and CSCs for primary incisors receiving pulpectomy. However, a need for further well-designed RCTs was observed.

Generative adversarial networks using a cycle-consistency loss facilitate unpaired training of image-translation models and thereby exhibit a very high potential in manifold medical applications. However, the fact that images in one domain potentially map to more than one image in another domain (e.g. in case of pathological changes) exhibits a major challenge for training the networks. In this work, we offer a solution to improve the training process in case of many-to-one mappings by modifying the cycle-consistency loss. We show formally and empirically that the proposed method improves the performance significantly without radically changing the architecture and without increasing the overall complexity. We evaluate our method on thigh MRI scans with the final goal of segmenting the muscle in fat-infiltrated patients' data., Comment: Presented at IEEE ISBI'21

Nach der Abkehr vom Amalgam ist die Adhasivtechnik im Milchgebiss heute Routine in der Kinderzahnheilkunde. Es ist jedoch nicht statthaft, die Regeln der adhasiven Vorbehandlung der Zahnhartsubstanzen vom bleibenden Gebiss auf die Milchzahne zu ubertragen. Bereits die Mikromorphologie von Milchzahnschmelz und -dentin ist eine andere. Neben aktuellen Literaturaspekten werden auch eigene Untersuchungen zur Schmelz- und Dentinhaftung im Milchgebiss sowie zur damit erzielbaren Randqualitat vorgestellt. Die Haftung am Milchzahnschmelz ist nach Entfernung der prismenlosen Oberflache mit Phosphorsaure am zuverlassigsten. Milchzahndentin zeigt eine geringere Mineralisation und ist daher mit selbstatzenden Adhasiven i.d.R. einfach und sicher zu „bonden“. Von einer dezidierten Anwendung von Phosphorsaure auf Milchzahndentin wird abgeraten. Im Rahmen der Auswahl des Adhasivsystems zeigt sich im Gegensatz zur bleibenden Dentition kein Vorteil fur aufwendige Mehr-Schritt-Adhasivsysteme. Da simplifizierte selbstatzende Adhasive durch das nicht erforderliche Abspruhen inkl. Watterollenwechsel auch im Rahmen der Kinderbehandlung strategische Vorteile bieten, konnen diese auch aufgrund ihrer Dentinhaftung heute empfohlen werden. Eine selektive Schmelzatzung ist im Frontzahnbereich sinnvoll, im Seitenzahnbereich eher nur im okklusalen Kavitatenabschnitt.

BACKGROUND Fat-fraction has been established as a relevant marker for the assessment and diagnosis of neuromuscular diseases. For computing this metric, segmentation of muscle tissue in MR images is a first crucial step. PURPOSE To tackle the high degree of variability in combination with the high annotation effort for training supervised segmentation models (such as fully convolutional neural networks). STUDY TYPE Prospective. SUBJECTS In all, 41 patients consisting of 20 patients showing fatty infiltration and 21 healthy subjects. Field Strength/Sequence: The T1 -weighted MR-pulse sequences were acquired on a 1.5T scanner. ASSESSMENT To increase performance with limited training data, we propose a domain-specific technique for simulating fatty infiltrations (i.e., texture augmentation) in nonaffected subjects' MR images in combination with shape augmentation. For simulating the fatty infiltrations, we make use of an architecture comprising several competing networks (generative adversarial networks) that facilitate a realistic artificial conversion between healthy and infiltrated MR images. Finally, we assess the segmentation accuracy (Dice similarity coefficient). STATISTICAL TESTS A Wilcoxon signed rank test was performed to assess whether differences in segmentation accuracy are significant. RESULTS The mean Dice similarity coefficients significantly increase from 0.84-0.88 (P < 0.01) using data augmentation if training is performed with mixed data and from 0.59-0.87 (P < 0.001) if training is conducted with healthy subjects only. DATA CONCLUSION Domain-specific data adaptation is highly suitable for facilitating neural network-based segmentation of thighs with feasible manual effort for creating training data. The results even suggest an approach completely bypassing manual annotations. LEVEL OF EVIDENCE 4 Technical Efficacy: Stage 3.

Die Erstvorstellung der 30-jährigen IG/0P erfolgte mit 26+1 Schwangerschaftswochen (SSW) zur weiteren Betreuung nach extern erfolgter Amniozentese und bereits molekulargenetisch gesicherter fetaler Tuberöser Sklerose (Mutation im TSC2-Gen).

Results suggest that focused, abbreviated biparametric prostate MR imaging is as useful to help detect clinically significant prostate cancer in men with elevated prostate-specific antigen as is regular, multiparametric prostate MR imaging.

Supplemental material, sj-pdf-1-jct-10.1177_2380084420975333 for Toothbrushing Performance and Oral Cleanliness after Brushing in 12-Year-Old Children by U. Weik, O. Cordes, J. Weber, N. Krämer, K. Pieper, J. Margraf-Stiksrud and R. Deinzer in JDR Clinical & Translational Research

Supplemental material, sj-pdf-1-jct-10.1177_2380084420975333 for Toothbrushing Performance and Oral Cleanliness after Brushing in 12-Year-Old Children by U. Weik, O. Cordes, J. Weber, N. Krämer, K. Pieper, J. Margraf-Stiksrud and R. Deinzer in JDR Clinical & Translational Research

The aim of the present cross-sectional study was to assess and compare the prevalence of MIH among 6-12-year-old school children living either in a rural area of Central Hesse (Germany) or in the city of Frankfurt on the Main (Germany). A possible association between hypomineralised second primary molars (HSPM) and MIH was investigated. Furthermore, the MIH prevalence data of the rural area were compared with those of a previous study conducted in this area in the school year 2002/2003.In the school year 2014/2015, 2103 children (6-12 years of age) were examined during the annual school-based dental examinations prescribed by law at nine schools in the rural area of Central Hesse (LDK) and five schools in the city of Frankfurt on the Main (Ffm). Eight previously calibrated dentists working for the public healthcare authorities assessed the prevalence of HSPM/MIH (EAPD criteria/severity scale by Wetzel and Reckel) and the caries experience (dmft/DMFT).The prevalence of HSPM/MIH amounted 3.2%/9.4% in LDK and 2.9%/17.4% in Ffm. In the majority of cases, children with MIH had demarcated opacities. In LDK, hypomineralised first permanent molars were most commonly affected by severity degree 2, whereas in Ffm, severity degree 1 was predominant. Children suffering from HSPM had an odds ratio of 11.32 (95% CI: 6.73-19.03) for having MIH as well. Compared with the results of 2002/2003 in LDK (prevalence of MIH 5.9%), the MIH prevalence increased by 3.5% in the rural area. All in all, the caries experience among children under investigation was low (DMFT 0.14-0.15).MIH may be diagnosed in school children living in different areas of Germany with regional variations (rural-urban comparison). The presence of HSPM is of predictive value for MIH. The increasing number of hypomineralised first permanent molars over 12 years of time in the rural area indicates a need for further investigation on the aetiology of MIH.

Muscle nerve 61(5), 600-607 (2020). doi:10.1002/mus.26827, Published by Wiley, New York, NY [u.a.]

This was to evaluate the wear resistance of different materials, compomers, resin-modified glass ionomer cements (RMGICs), glass ionomer cements (GICs), used for posterior restorations in primary teeth and to compare the results with the reference material, amalgam. Eight specimens of each material were subjected to two-body wear test, using a chewing simulator. The wear region of each material was examined under a profilometer, measuring the vertical loss (μm) and the volume loss (mm3) of the materials. The results showed significant differences of vertical loss and volume loss of the test materials (p

Trotz aller Praventionserfolge in den letzten Jahren ist der Kariesbefall im Milchgebiss nach wie vor hoch. Trotzdem spielt die Sanierung von kariosen Milchzahnen in der Bundesrepublik nach wie vor eine untergeordnete Rolle. Dies ist umso erstaunlicher, als fur die Fullungstherapie in den letzten Jahren erfolgreiche Konzepte vorgestellt wurden. Die einfache Handhabung und die Weiterentwicklung von Fullungsmaterialien mit verbesserten asthetischen und werkstoffkundlichen Eigenschaften ermoglichen eine defektorientierte und minimal-invasive Therapie auch in der ersten Dentition. Aufgrund der positiven klinischen Ergebnisse gelten Kompomere heute fur die Fullungstherapie im Front- und Seitenzahnbereich des Milchgebisses als Mittel der Wahl. Je nach Compliance der Kinder und der Aktivitat und Grose der kariosen Lasion ist jedoch an eine alternative Versorgung zu denken. Bei groseren Defekten und erhohtem Kariesrisiko sollten Milchzahne mit konfektionierten Kronen versorgt werden. Bei schlechter Compliance sind Glasionomerzemente der adhasiven Versorgung vorzuziehen, um zumindest Zeit zu uberbrucken und den „Infektionsherd“ Karies aus der Mundhohle zu eliminieren.

Early childhood caries (ECC) is closely related to high numbers of mutans streptococci, lactobacilli and Candida albicans. Oral colonization of these microorganisms was monitored in a prospective clinical study in order to investigate the effect of comprehensive treatment under general anesthesia and the sustainability of microbial changes. Saliva samples were collected from 50 healthy infants with ECC before and in regular intervals up to 12 months after treatment. Microorganisms were detected by cultivation on selective agars (CRT® bacteria and Sabouraud/CandiSelect™) and scored. Additionally, plaque on upper front teeth and the dmft were recorded. Parents were repeatedly interviewed regarding the children's diet and oral hygiene, accompanied by corresponding advice. Plaque frequency and the numbers of mutans streptococci, lactobacilli and yeasts were significantly reduced as a result of treatment (p < 0.0001, Wilcoxon test). Nevertheless, this effect was not permanent. An ordinal regression model on the follow-up period revealed that the odds for bacteria and yeasts to reach a higher score increased linearly over time (p < 0.01) with an odds ratio of 2.244 per year. One third (34%) of the children developed new dentinal lesions within 1 year postoperatively. High scores of lactobacilli before treatment predicted caries relapse (p < 0.05). Nutritional and oral hygiene habits changed only slightly despite advising. Elimination and restoration of ECC lesions under general anesthesia proved to be an effective procedure in reducing cariogenic bacteria and yeasts. A satisfactory and sustainable success, however, could be achieved neither regarding microbiologic parameters nor with respect to the relapse rate. More suitable strategies are needed.

Aim In paediatric dentistry, epinephrine may contribute to systemic and local side-effects. On the other hand it is necessary to provide good and safe local analgesia. Therefore, an articaine solution with reduced epinephrine concentration was tested in a clinical setting. Methods In a non-interventional clinical study, dental treatment was performed in children and adolescents (4–17 years). For local analgesia, articaine 4 % plus epinephrine 1:400,000 was used in the technique chosen by the dentist. Efficacy and tolerance as well as duration of soft tissue analgesia and side-effects were evaluated. Results 999 patients (50.5 % male, 49.5 % female) with a mean age of 7.9 (SD 2.34) years were treated. Two hundred seventy six patients (27.6 %) received sedation prior to treatment. The mean treatment time was 15 min (SD 10). In 93.5 % of cases, initial local analgesia was sufficient to perform the planned treatment. In 99 % of cases (n = 989) the planned treatment could be completed. A second injection was necessary in 6.5 % of cases. A mean duration of soft tissue analgesia of 2.19 h (SD 1.01) was seen. Slight side-effects occurred in 3.1 % of subjects. Conclusions Due to high efficacy, tolerance and safety, the articaine 4 % solution with the reduced epinephrine concentration (1:400,000) was a safe and suitable drug for paediatric routine treatment.

This was to create a new easy-to-use index for the treatment of MIH. An international MIH working group developed a new MIH index as an epidemiological screening procedure for assessing MIH treatment needs (MIH-TNI), and also for the screening and monitoring of individuals by dental practitioners. The MIH TNI assesses in particular the extent of the destruction of tooth structure in combination with any hypersensitivity occurring in MIH. The MIH-TNI is suggested as a basis for individual dental examinations covering all MIH typical problems or treatment planning. In addition, this index shall be the basis for decision-making in any MIH therapy studies already planned. After the validation of the MIH TNI it may be possible to create a standardised approach for dental treatment for MIH.

To compare image quality and accuracy of left ventricular function of cine SSFP (steady-state free precession) images before and after injection of Gd-DTPA. In 30 patients T1 times of LV blood and myocardium were measured before and after injection of 0.2 mmol/kg body weight Gd-DTPA. Signal intensity of myocardium and left ventricular blood were measured on SSFP images and the contrast calculated. In 20 additional patients short axis images completely covering the left ventricle were acquired before and after injection of Gd-DTPA and parameters of left ventricular function compared. Image quality and regional function were assessed using the 17-segment model. Image quality after injection of contrast medium did not significantly change compared with unenhanced images. Contrast between myocardium and LV blood decreased from 0.6 ± 0.01 to 0.4 ± 0.03 after injection while the T1 value of myocardium decreased from 1121 ± 21 ms to 389 ± 14 ms (blood 1413 ± 48 ms to 222 ± 8 ms). Assessment of regional and global left ventricular function revealed similar results before and after the injection of contrast medium. Cine SSFP can be obtained after injection of contrast medium without loss of accuracy for regional and global LV ventricular function. This protocol can be used to decrease imaging time for thorough cardiac examination.

Purpose: To develop a method for visualizing surgical textile implant (STI) with superparamagnetic iron oxides (SPIO), using magnetic resonance imaging (MRI). Therefore, positive-contrast inversion-recovery with on-resonant water suppression (IRON) was applied and its properties were evaluated in vitro. Materials and Methods: STI with different concentrations of SPIO integrated into the base material were produced. Imaging was performed on a clinical 1.5 Tesla scanner, using conventional balanced gradient echo sequences (SSFP), T2 * -weighted sequences, and IRON-imaging. In vitro experiments were conducted in an agarose phantom. On MR-images, contrast-to-noise-ratios, and the dimensions of the implant were assessed. Results: Conventional MRI exhibited SPIO-loaded STI as signal voids. Using IRON, the mesh was clearly exhibited hyperintensely with suppression of on-resonant background signals with a distinct differentiation to other sources of off-resonances. Concentrations of approximately 9 mg/g led to best positive contrast and highest contrast-to-noise-ratios using IRON. Depending on B 0 -orientation, phase encoding direction and the STI's SPIO-load, the IRON-signal showed a characteristic pattern and an overestimation of STI size up to 4.6 mm. Conclusion: The integration of SPIOs into the base material combined with IRON is a feasible approach to visualize STI with MRI. This method could help to identify mesh-related problems in time and to reduce the need for surgical revision.

Objectives To visualize the coronary sinus using magnetic resonance (MR), and to demonstrate the feasibility of MR-guided intubation of the cardiac venous system (CVS) in swine. Materials and methods A total of 6 pigs were investigated. All experiments were performed using an interventional 1.5-Tesla MRI system. The CVS was visualized using an inversion-recovery navigator-gated whole-heart steady-state free-precession sequence after administration of gadobenate dimeglumine contrast agent. The coronary sinus was then intubated under MR-guidance with a passive MR-compatible guidewire modified by incorporation of iron oxide markers for improved visualization and a nonbraided Cobra-catheter. MR-guided interventions were monitored using a steady-state free-precession real-time imaging sequence. Time needed was measured for MR-guided intubation of the CVS and compared with the time needed for fluoroscopy guided intubation of the CVS. Results Visualization and intubation of the coronary sinus and its site branches was feasible in all cases. Time spent for MR-guided intubation of the CVS was comparable to time spent for fluoroscopy-guided intubation (8.2 +/- 2 minutes vs. 8.3 +/- 1.3 minutes; P = 0.85). Conclusions MR-visualization and MR-guided intubation of the coronary sinus and its side branches is feasible. The feasibility of MR-guided intubation of the CVS might have relevance for procedures like cardiac resynchronization therapy and percutaneous transcatheter mitral annuloplasty, requiring improved 3-dimensional knowledge about cardiac vein anatomy in the near future.

Objectives The aim of this study was to analyze whether cardiac computed tomography (CT) permits the assessment of myocardial edema in acute myocardial infarction (MI). Background Several studies proved the value of detecting myocardial edema from T2-weighted cardiac magnetic resonance (CMR) for differentiating acute from chronic MI. Computed tomography is suited for depicting MI, but there are no data on CT imaging of myocardial edema. We hypothesized that areas of reduced attenuation in acute MI may correspond to edema. Methods In 7 pigs (55.2 ± 7.3 kg), acute MI was induced using a closed chest model. Animals underwent unenhanced arterial and late-phase dual source computed tomography (DSCT) followed by T2-weighted and delayed contrast-enhanced CMR. Animals were sacrificed, and the excised hearts were stained with 2,3,5-triphenyltetrazolin chloride (TTC). Size of MI, contrast-to-noise ratio, and percent signal difference were compared among the different imaging techniques with concordance-correlation coefficients (ρc), Bland-Altman plots, and analysis of variance for repeated measures. Results Infarction was transmural on all slices. On unenhanced, arterial, and late-phase DSCT, mean sizes of MI were 27.2 ± 8.5%, 20.1 ± 6.9%, and 23.1 ± 8.2%, respectively. Corresponding values on T2-weighted and delayed enhanced CMR were 28.5 ± 7.8% and 22.2 ± 7.7%. Size of MI on TTC staining was 22.6 ± 7.8%. Best agreement was observed when comparing late-phase CT (ρc = 0.9356) and delayed enhanced CMR (ρc = 0.9248) with TTC staining. There was substantial agreement between unenhanced DSCT and T2-weighted CMR (ρc = 0.8629). Unenhanced DSCT presented with the lowest percent signal difference (46.0 ± 18.3) and the lowest contrast-to-noise ratio (4.7 ± 2.0) between infarcted and healthy myocardium. Conclusions Unenhanced DSCT permits the detection of myocardial edema in large acute MI. Further studies including smaller MI in different coronary artery territories and techniques for improving the contrast-to-noise ratio are needed.

Purpose: Interventional magnetic resonance imaging requires dedicated and MR-compatible devices. The guidewire is a key item for intravascular interventions. Mechanical stability, good visibility during real-time imaging, and RF safety are essential. A novel fiber-compound MR guidewire (GW) was evaluated in different MR-guided interventional scenarios. Materials and Methods: The GW (diameter 0.032") consists of a fiber-compound produced using a micropultrusion technique doped with iron particles and a 10-cm Nitinol tip. Several iron splints are additionally attached at regular distances to visualize GW-movement. A protective polymer jacket with hydrophilic coating covers the core material. As approved by the government committee on animal investigations, the GW was evaluated in 5 pigs. Under complete MR-guidance, catheterization of the carotid and renal arteries, segmental arteries of the kidneys, the contralateral inguinal artery, and the left ventricle was performed using real-time gradient echo sequences in a 1.5 Tesla scanner. Different interventional applications including balloon dilatation, stent deployment, and embolization of small vessels were investigated. The time to probe the vessels under magnetic resonance imaging guidance and visibility of the GW are assessed. Handling and visibility under fluoroscopy were compared with a standard Nitinol guidewire as a benchmark. Results: On real-time magnetic resonance imaging, the iron-induced artifacts enabled a distinct visualization of the GW shaft and of its markings with a mean size of 2.6 mm and 5.4 mm, respectively. This facilitated fast navigation to the target vessels (averages: renal arteries 16 seconds, carotid artery 5 seconds, and contralateral inguinal artery 42 seconds.) with an exact depiction of the respective vessel. All interventional procedures were performed successfully. No GW-related side effects as kinking or breakage of the wire or GW induced blood-clotting were observed. All interventionalists assessed handling of the GW to be nearly equal in terms of stiffness, flexibility, and guidance compared with a standard Nitinol guidewire. X-ray visibility was less distinct but still diagnostically good. Conclusion: With the aid of the GW, different fully real-time MR-guided endovascular interventions become feasible.

Objective Aim of the present study was to evaluate the clinical suitability of the condensable metal-reinforced glass ionomer cement Hi-Dense in classes I and II cavities of primary molars. Methods Seventeen children received a total of fifty four Hi-Dense fillings (nineteen class I and thirty five class II). The restorations were clinically assessed at baseline, after one and after two years of clinical service according to modified USPHS codes and criteria. The restorations were replicated in each recall and representative samples were qualitatively analysed under a SEM. Results Over the observation period of two years, five restorations failed due to total retention loss, two fillings needed replacement because of persisting hypersensitivity, one filling was lost because of an unsuccessful endodontic treatment, and four restorations remained intact until natural exfoliation (Two year survival rate: 92% for Class I and 66% for Class II). The SEM analysis of surfaces and marginal areas exhibited an inferior adhesive performance primarily in proximal areas, whereas a negative step formation due to wear was frequently observed in occlusal parts. Conclusions The results clearly indicate that the condensable, metal-reinforced GIC Hi-Dense reveals no enhanced performance and lifetime expectancy for class II restorations in primary molars when compared to other non-resin-modified GICs.

A dynamical generalization of the instantaneous normal mode (INM) theory of liquid state dynamics is presented. Due to anharmonicities the eigenvalues and eigenvectors of the Hessian matrix change with time. Therefore, regular INM theory gives a description of molecular dynamics valid only for short times. Starting out from the classical equations of motion the velocity correlation function is expressed in terms of a series of propagation matrices. These are calculated by diagonalizing the Hessian matrix at configurations equidistant in time along a short piece of trajectory. Correlation functions calculated by this normal mode propagation (NMP) for a representative selection of atomic systems agree quantitatively with results from molecular-dynamics simulation.

The main feature of the well-known technique of confocal scanning microscopy is that of optical sectioning. This capability allows threedimensional reconstruction of the topometry of technical surfaces, built up from a series of hundreds of depth discriminated height sections. Based on this fundamental principle, several confocal microscopes have been realized with high axial and lateral resolutions. For a drastically enlarged field and a significant reduction in measuring time, a chromatic confocal method using microlenses has been developed. When measuring an object the topography can be determined by 4 chromatic coded images and, in contrast to conventional techniques, there is no need for mechanical height stepping in the axial direction. For this reason real-time measuring has become possible. First results with this set-up are presented.

Early childhood caries (ECC) is closely related to high numbers of mutans streptococci, lactobacilli and Candida albicans. Oral colonization of these microorganisms was monitored in a prospective clinical study in order to investigate the effect of comprehensive treatment under general anesthesia and the sustainability of microbial changes. Saliva samples were collected from 50 healthy infants with ECC before and in regular intervals up to 12 months after treatment. Microorganisms were detected by cultivation on selective agars (CRT® bacteria and Sabouraud/CandiSelect™) and scored. Additionally, plaque on upper front teeth and the dmft were recorded. Parents were repeatedly interviewed regarding the children's diet and oral hygiene, accompanied by corresponding advice. Plaque frequency and the numbers of mutans streptococci, lactobacilli and yeasts were significantly reduced as a result of treatment (p0.0001, Wilcoxon test). Nevertheless, this effect was not permanent. An ordinal regression model on the follow-up period revealed that the odds for bacteria and yeasts to reach a higher score increased linearly over time (p0.01) with an odds ratio of 2.244 per year. One third (34%) of the children developed new dentinal lesions within 1 year postoperatively. High scores of lactobacilli before treatment predicted caries relapse (p0.05). Nutritional and oral hygiene habits changed only slightly despite advising. Elimination and restoration of ECC lesions under general anesthesia proved to be an effective procedure in reducing cariogenic bacteria and yeasts. A satisfactory and sustainable success, however, could be achieved neither regarding microbiologic parameters nor with respect to the relapse rate. More suitable strategies are needed.

Conventional radiological methods, including magnetic resonance imaging (MRI), fail to visualize polymeric surgical mesh implants because of small thread dimensions and material characteristics. For MRI delineation of such meshes, superparamagnetic iron oxide particles (SPIOs) are integrated in the mesh polymer. Usually, if SPIOs are used as an intravenous contrast agent, they increase the R1 and R2 of adjacent protons. It can be assumed that embedding SPIOs in polymers alters their molecular dynamics. The aim of this study was to investigate the influence of SPIO integration in polymer on the relaxation of adjacent protons.Polymer threads were placed in an agarose phantom. At 1.5 T, R1, R2, and R2* maps were calculated from multi inversion-recovery spin echo, multi-spin echo, and multi-gradient echo images, respectively. The threads were aligned parallel or orthogonal to B(0).No impact of SPIO on proton R1 and R2 was observed. R2* was increased by the SPIO-loaded threads. R1 and R2 amplitude maps showed a magnetic susceptibility difference of 0.97 ppm/(mg SPIO/g polymer) around SPIO-loaded threads.In contrast to SPIO in aqueous solutions, polymer-embedded SPIO do not affect proton R1 and R2. However, embedded SPIO generate strong local static magnetic field gradients. Thus, SPIO integration is suitable to control the magnetic susceptibility of polymer threads. This can be exploited to visualize implanted polymer-based meshes in MRI using R2* susceptible sequences. Because no impact on R1 and R2 of adjacent protons by SPIO embedded in mesh threads was observed, structures adjacent to implanted meshes will be observable in R1 and R2 maps.

Background— Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results— In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions— The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution.

The magnetic properties of superparamagnetic iron oxides (SPIOs) and their distribution within PVDF-filaments of textile implants are investigated by means of a superconducting quantum interference device (SQUID), a transmission electron microscope (TEM), a magnetic force microscope (MFM) and magnetic resonance imaging (MRI). These analyses are necessary for quality control in manufacture and the depiction of an implant in MRI.

For the development of a surgical mesh implant that is visible in magnetic resonance imaging (MRI), superparamagnetic iron oxides (SPIOs) are integrated into the material of the mesh. In order to get a high quality mesh regarding both mechanical and imaging properties, a narrow size distribution and homogenous spatial distribution, as well as a strong magnetization of SPIOs within the filament of the mesh are required. In this work, six different samples of SPIOs composed of a magnetite core are synthesized with and without stabilizing dodecanoic acid and analyzed using a superconducting quantum interference device (SQUID), transmission electron microscope (TEM) and a magnetic force microscope (MFM) to determine the properties that are beneficial for the assembly and imaging of the implant. These analyses show the feasibility of visualization of surgical implants with incorporated SPIOs and the influence of the agglomeration of SPIOs on their magnetization and on a homogenous spatial distribution within the polymer of the mesh.