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Objectives: The introduction of diode lasers in dentistry had several advantages, principally consisting on the reduced size, reduced cost and possibility to beam delivering by optical fibbers. Up today only the wavelengths around 810 and 980 nm were the most utilized in oral surgery but recently more different lasers had been proposed. The aim of this study was to compare the efficacy of four diode laser wavelengths (810, 980, 1470 and 1950 nm) for the ablation of soft tissues. Material and methods: Specimens were surgically collected from the dorsal surface of four bovine tongues and irradiated by four different diode wavelengths. Thermal increase was measured by two thermocouples, the first at a depth of 0.5 mm, and the second at a depth of 2 mm. Initial and final surface temperatures were recorded by IR thermometer. Epithelial changes, connective tissue modifications, presence of vascular modification and incision morphology were histologically evaluated by two blind pathologists. Results: The time necessary to perform the excision varied between 271 seconds (808 nm, 2W) and 112 seconds (1950 nm, 4W). Temperature increase superficial level varied from 16.3° (980 nm, 4W) and 9.2° (1950 nm, 2 W). The most significant deep temperature increase was recorded by 980 nm, 4 W (17.3°) and the lowest by 1950 nm, 2 W (9.7°). The width of epithelial tissue injuries varied between 74 pm from 1950 nm diode laser at 2 W to 540 pm for 1470 nm diode laser at 4 W. Conclusion: The quality of incision was better and the width of overall tissue injuries was minor in the specimens obtained with higher wavelength (1950 nm) at lower power (2W).

The cancer risk of patients with inflammatory bowel diseases (IBD) has not been well documented in southern Europe. This study aimed to evaluate the overall pattern of cancer risk among patients with IBD in Friuli Venezia Giulia, northeastern Italy. A population-based cohort study was performed through a record linkage between local healthcare databases and the cancer registry (1995–2013). We identified 3664 IBD patients aged 18–84 years, including 2358 with ulcerative colitis (UC) and 1306 with Crohn’s disease (CD). Sex- and age-standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were used to compare the cancer incidence of IBD patients with the general population. The cumulative cancer risk among IBD patients reached about 10% after 10 years of follow-up. A total of 246 cancers occurred among UC patients (SIR = 1.05, 95% CI: 0.92–1.19), and 141 among CD patients (SIR = 1.20, 95% CI: 1.01–1.41). As compared with the general population, no increased risk of colorectal cancers was observed for either UC or CD patients, whereas the risk of anal cancer was significantly elevated among UC patients (SIR = 6.03, 95% CI: 1.24–17.60). Increased risks were seen for specific extra-intestinal cancers, including corpus uteri (SIR = 2.67, 95% CI: 1.07–5.50) and kidney (SIR = 2.06, 95% CI: 1.03–3.69) among UC patients; thyroid (SIR = 5.58, 95% CI: 2.41–11.00) and skin non-melanoma (SIR = 1.86, 95% CI: 1.32–2.55) among CD patients. This population-based study showed that both UC and CD patients had a colorectal cancer risk similar to that of the general population. However, they were at a higher risk of developing certain extra-intestinal cancer types. Although detection biases cannot be excluded, the study findings pointed to a role of long-standing exposures to immunosuppressive therapies, underlying disease status, as well as the interactions with lifestyle factors. Our findings lent additional support to the need for monitoring the cancer burden in this at-risk population.

Poster: "ECR 2015 / B-0456 / The impact of Gadolinium-based contrast agent in the assessment of Crohn’s disease activity: Is it contrast agent injection necessary?" by: "E. Quaia, M. Pontello, R. Angileri, M. A. Cova; Trieste/IT"

The inscription of relief Bragg grating reflectors on the capillary walls of a solid-core photonic crystal fiber (PCF) using laser radiation is presented. The inscription method followed is based on the infiltration and adsorption of a thin layer of toluene on the capillaries of the PCF and the subsequent exposure of the infiltrated fiber using 248-nm excimer laser radiation and phase mask interference. Gratings are characterized spectrally and by scanning electron microscopy while their sensing capabilities are exemplified by infiltrating them with organic solvents. Thermal studies revealed that the gratings exhibit high thermal endurance characteristics, withstanding tens of hours annealing at 950°C.

Background: The Er:YAG laser in conservative dentistry is. good alternative to conventional instruments. Though several studies show the advantages of these devices, some drawbacks and unsolved problems are still present, such as the cost of the device and the large dimensions of the equipment. Purpose: In the present study, the effectiveness of dental surface ablation with a picosecond infrared diode-pumped solid-state (DPSS) laser was investigated. In vitro tests on extracted human teeth were carried out, with assessment of the ablation quality in the tooth and thermal increase inside the pulp chamber. Materials and Methods: A solid-state picosecond laser was used for the experiments. The samples were exposed to laser energy at 1064 nm at a frequency of 30 kHz and a 500 ps pulse width. The target teeth were cooled during exposures. The internal temperature of the pulp chamber was monitored with. thermocouple. Results: Optical microscope images showed effective ablation with the absence of carbonisation and micro-cracks. The cooling maintained the temperature rise in the pulp chamber below the permitted 5.5°C. Discussion: The main problem with the use of lasers in dentistry when teeth are the target is the heat generated in the pulp chamber of the target teeth. With lasers operating in the femtosecond mode, a better management of the internal temperature is possible, but is offset by the high cost of such devices. With the ps domain system used in the present study together with cooling using chilled water, effective and clean ablation could be achieved with a controlled thermal effect in the pulp chamber. Conclusions: In this preliminary study with a picosecond domain DPSS laser using water cooling for the target, effective hard tissue ablation was achieved keeping the thermal increase in the pulp within the permitted range. The results suggest that this system could be used in clinical practice with appropriate modifications.

Rationale and Objectives: To define the best independent predictors for active inflammation in patients with Crohn disease (CD) examined by contrast-enhanced magnetic resonance (MR) enterography. Materials and Methods: Ninety-one patients (47 men and 44 women; aged 39.58 17.1 years) with a diagnosis of CD; CD activity index (CDAI)$150 (n = 19 patients) or

Purpose To assess whether contrast material-enhanced ultrasonography (US) can be used to differentiate responders from nonresponders among patients with clinically active Crohn disease after 6 weeks of pharmacologic treatment. Materials and Methods This prospective study was approved by our ethics committee, and written informed consent was obtained from all patients. Fifty consecutive patients (26 men and 24 women; mean age, 34.76 years ± 9) with a proved diagnosis of active Crohn disease who were scheduled to begin therapy with biologics (infliximab or adalimumab) were included, with enrollment from June 1, 2013, to June 1, 2015. In each patient, the terminal ileal loop was imaged with contrast-enhanced US before the beginning and at the end of week 6 of pharmacologic treatment. Time-intensity curves obtained in responders (those with a decrease in the Crohn disease endoscopic index of severity score of 25-44 before treatment to 10-15 after treatment, an inflammatory score

In this work the application of different laser wavelengths, in combination with different photosensitizing dyes, to bacterial cultures, in liquid or solid mean, has been investigated. Two types of Streptococcus mutans cultures have been used for the experiments, inside agar and saline solution. Three different laser wavelengths have been applied to the bacterial cultures together with a photosensitizing dye: red diode (650 nm) on cultures stained with Toluidine Blue, blueviolet diode (450 nm) on cultures stained with Curcumin and KTP laser (532 nm) on cultures stained with Erythrosine. The choice of the dye has been made considering the color affinity with the used wavelength. Tests without dyes have also been performed. Experimental results show that the maximum inhibition of bacterial growth with the blue laser has been obtained in a saline solution with a growth of 40.77%. While the combination with Curcumin lead to an inhibition growth of about 99.1%, for a laser fluence of 30J/cm 2 . No inhibition has been observed using the red laser in saline solution without dye, while the combination with Toluidine Blue resulted in a 100% inhibition growth for 20 and 30 J/cm 2 fluences. An inhibition growth of just 16.26% has been obtained with the use of KTP laser in saline solution without dye. The use of Erythrosine had the effect of a complete inhibition growth. From the obtained results it is possible to observe that the combination of laser wavelength with a particular photosensitizing dye can dramatically increase the bacterial growth.

The introduction of diode lasers in dentistry has several advantages, mainly consisting on the reduced size, reduced cost and possibility to beam delivering by optical fibers. At the moment the two diode wavelengths normally utilized in the dental field are 810 and 980 nm for soft tissues treatments. The aim of this study was to compare the efficacy of four different diode wavelengths: 810, 980, 1470 and 1950 nm diode laser for the ablation of soft tissues. Several samples of veal tongue were exposed to the four different wavelengths, at different fluences. The internal temperature of the soft tissues, in the area close to the beam, was monitored with thermocouple during the experiment. The excision quality of the exposed samples have been characterized by means of an optical microscope. Tissue damages and the cut regularity have been evaluated on the base of established criteria. The lowest thermal increase was recorded for 1950 nm laser. Best quality and speed of incision were obtained by the same wavelength. By evaluating epithelial, stromal and vascular damages for all the used wavelengths, the best result, in terms of “tissue respect”, have been obtained for 1470 and 1950 nm exposures. From the obtained results 1470 and 1950 nm diode laser showed to be the best performer wavelengths among these used in this “ex vivo” study, probably due to their greatest affinity to water.

The pico- and nano-second ablation thresholds and subsequent pulse-energy cut-depth and width relationships of aluminium, polypropylene (PP), polyethylene (PE) and their various thin-film combinations have been determined at 515 nm and 1064 nm. High quality incisions were obtained for all structures within certain parameter ranges. All ablation thresholds were found to be functions of the temporal pulse-width. Numerical simulations revealed the underlying mechanisms as phase explosion and thermal conduction. The presented results provide necessary parameters for the efficient cut and scribe of such materials, allowing the laser to prevail in lieu of more costly and energy intensive methods.

The pulsed laser ablation of 20 micron thick aluminium foil is investigated by exposing moving samples to picosecond pulses of wavelength 1064nm and nanosecond pulses of wavelength 515nm and 1030nm. Ablation thresholds and depths are determined for a range of conditions using an optical microscope and 3D optical profiler. Complete three-dimensional crater profiles for single and multiple pulses are presented. The results reveal a variation in ablation threshold with wavelength, pulse duration and the number of pulses; a large reduction is observed for picosecond pulses. Ablation rates per pulse are expressed by general equations and found to vary strongly with both laser type and the number of pulses. The green nanosecond laser is found to ablate most efficiently for fluences above 10J/cm2, whilst the picosecond source is instead advantageous for low fluences. A large reduction in ablation depth per pulse is observed with an increasing number of pulses. The present work affords prediction of scribe and cut parameters for the processing of thin aluminium layers and, more generally, characterises the driving parameters of pulsed picosecond and nanosecond laser ablation of metals.Copyright © 2013 by ASME

Several studies have been presented on the photosensitivity and index engineering of phosphate glasses using high intensity ultraviolet [1, 2] lasers. These studies are of particular interest due to the increased number of applications of rare-earth codoped phosphate glasses in the development of high efficiency planar and fibre active components. We present results on the Bragg grating recording behavior and photosensitivity of an all-phosphate glass rare earth doped optical fibre, utilizing 248nm, 500fs laser radiation. In the grating inscription results presented, non-monotonic refractive index changes with respect to accumulated energy density are observed. This unique behavior resembles that of the Type IIA photosensitivity mechanism that usually occurs during grating recording in high-Ge doped silicate glass optical fibres using deep ultraviolet laser sources; however, never been observed before in grating recording in soft glasses, including phosphate glass fibres. Moreover, the origin of the negative refractive index changes induced, is investigated utilizing Knoop micro-hardness (HK) measurements, performed in irradiated and side-polished fibres [3]. The Bragg grating inscription was performed using a 248nm, 500-fs KrF excimer-dye laser system, at a 10Hz repetition rate. The experimental set-up used for grating recording was a double phase mask interferometer, being described elsewhere [4]. A single mode phosphate glass, Er/Yb codoped phosphate glass optical fibre, manufactured by INO-Canada, was exposed. The concentration of the rare earth dopants in the fibre are 0.90wt% for Er, and 7.0wt% for Yb.

Helicobacter pylori infecting strains may include colony subtypes with different cytotoxin-associated gene (cag) genotypes. We sought to determine whether the cag heterogeneity of infecting strains is related to the clinical outcome of infection. Gastric biopsies for culture and histologic study were taken from 19 patients infected with cagA-positive strains (6 with duodenal ulcer, 8 with atrophic gastritis, and 5 with nonatrophic gastritis). For each biopsy, DNA was extracted from 10 single colonies and from a sweep of colonies. Polymerase chain reaction (PCR) for cagA and cagE (both located in the right half of cag) and virB11 (located in the left half of cag) was performed. Random amplified polymorphic DNA PCR (RAPD-PCR) and sequencing of glmM PCR product were performed to verify strain identity of colonies with different cag genotypes. In all patients, PCR from sweeps were positive for cagA, showing that all specimens contained cagA-positive H. pylori subtypes. In 11 patients, PCR products from all colonies were positive for cagA, cagE, and virB11, but in 8 patients, PCR products from varying numbers of colonies were negative for 1 or more cag genes. RAPD-PCR and sequencing of glmM PCR product confirmed the strain identities of colonies with different cag genotypes. We detected cag deletions in 6 of 8, 2 of 5, and 0 of 6 patients with atrophic gastritis, nonatrophic gastritis, and duodenal ulcer, respectively (P = .02). In conclusion, changes in cag genotype in single colony isolates from subjects infected with cagA-positive H. pylori strains are more common in atrophic than in nonatrophic gastritis or duodenal ulcer. These findings are consistent with host-induced (acid secretion?) adaptive changes in cag genotype during infection.

Helicobacter pylori (H. pylori) is a major factor in determining the risk for development of gastric adenocarcinoma through the intermediate steps of atrophic gastritis and intestinal metaplasia. Because H. pylori infection is highly prevalent in asymptomatic populations and only a few people develop cancer, additional factors may influence the risk for development of cancer, once infection is established. Some factors may pertain to differences among bacterial strains. Because infection by H. pylori strains possessing cagA (cytotoxin-associated gene A), a gene encoding a high-molecular-weight immunodominant antigen (CagA), is associated with enhanced induction of gastritis, the aim of our study was to evaluate potential differences in the prevalence and intensity of atrophy and intestinal metaplasia between CagA-positive and CagA-negative H. pylori-infected patients.Eighty H. pylori-infected patients among 120 consecutive dyspeptic patients referred for upper gastrointestinal endoscopy were studied. Six bioptic specimens were taken from the gastric antrum: five for histological examination, and one for urease test. The H. pylori status was determined by histology, CLO test, and serology (in a standardized ELISA) for serum IgG and IgA directed to H. pylori. The CagA status was determined by Western blotting to detect serum IgG antibodies to CagA. Gastritis was classified according to the Sydney System. A score from 0 to 3 was assigned to each of the following morphological variables: atrophy, intestinal metaplasia, and mononuclear and neutrophilic cell infiltration. The association between CagA status and histological features was assessed by means of the chi2 test for trend.Among the 80 H. pylori-infected patients 53 (66%) were CagA seropositive and 27 (34%) were CagA seronegative. The mean age of the two groups was similar. CagA-positive patients had significantly higher scores for atrophy (p = 0.006), intestinal metaplasia (p = 0.01), and mononuclear (p0.001) and polymorphonuclear (p = 0.002) cell infiltration than did CagA-negative patients. No differences in contrast, were found for H. pylori density.Infection with CagA-positive H. pylori strains is associated with an increased prevalence and intensity of antral atrophy and intestinal metaplasia, in addition to higher degrees of gastritis. Our results seem to suggest that the CagA status could be a helpful parameter to define a subgroup of H. pylori-infected patients at increased risk of developing gastric adenocarcinoma.

A young man with a previous history of episodes of mild solid food dysphagia was admitted with a total dysphagia. The esophagogastroduodenoscopy (EGDS) showed an extensive disruption of mucosal layer with a cul-de-sac in the lower part of the esophagus. Soon after the procedure, the patient suffered from an acute chest pain and subsequent CT scan demonstrated an intramural circumferential dissection of thoracic esophagus, and a mediastinal emphysema. An emergency right thoracotomy was performed, followed by a total esophagectomy with esophagogastroplasty and jejunostomy. The histopathology confirmed that mucosal and submucosal layers were circumferentially detached from muscular wall and showed an eosinophilic infiltration of the whole organ with necrosis and erosions of mucosal, submucosal and muscular layers. The diagnosis was esophageal perforation in eosinophilic esophagitis.

CONTEXT: Celiac disease is one of the most common lifelong disorders. Non-Hodgkin lymphoma is a possible complication of celiac disease and may lead to a large portion of lymphoma cases. OBJECTIVE: To quantify the risk for developing non-Hodgkin lymphoma of any primary site associated with celiac disease. DESIGN AND SETTING: Multicenter, case-control study conducted between January 1996 and December 1999 throughout Italy. PATIENTS: Cases were older than 20 years (median, 57; range, 20-92 years) with non-Hodgkin lymphoma of any primary site and histological type and were recruited at the time of the diagnosis. Controls were healthy adults (2739 men and 2981 women) from the general population. MAIN OUTCOME MEASURE: Positive test result for class A serum antiendomysial antibody. RESULTS: Celiac disease was diagnosed in 6 (0.92%) of 653 patients with lymphoma. Of the 6 cases, 3 were of B-cell and 3 were of T-cell origin. Four of 6 cases had lymphoma primarily located in the gut. In the control group, 24 (0.42%) had celiac disease. The odds ratio (adjusted for age and sex) for non-Hodgkin lymphoma of any primary site associated with celiac disease was 3.1 (95% confidence interval [CI], 1.3-7.6), 16.9 (95% CI, 7.4-38.7) for gut lymphoma, and 19.2 (95% CI, 7.9-46.6) for T-cell lymphoma, respectively. The risk for non-Hodgkin lymphoma for the overall population, which was adjusted for age and sex, was 0.63% (95% CI, - 0.12% to 1.37%). CONCLUSION: Celiac disease is associated with an increased risk for non-Hodgkin lymphoma, especially of T-cell type and primarily localized in the gut. However, the association does not represent a great enough risk to justify early mass screening for celiac disease

Laser technology has been extensively used for dental treatment since the 1990s. In particular hard tissue ablation is performed by Er:YAG lasers due to their affinity with water and hydroxipatite, thus avoiding the formation of micro- and macro-cracks, and thermal damaged areas. On the other hand Er:YAG lasers are affected by cumbersome instrumentation, and operation durations can be higher than the ones of traditional instruments. Records of dental surface treatment with ultra-short pulsed lasers, 150 - 500 fs, are also present, at such pulse duration remarkable results have been obtained, regardless to the laser emission wavelength.