The flexibility of NiTi based endodontic files is improved by heat treatment, leading to lower risk of failure, ledges, and canal transportation during the preparation of curved root canals. The aim ...of this study is to investigate and clearly highlight the influence of every parameter of heat treatment on the flexibility of NiTi wires and thus of endodontic instruments. A full factorial Design of Experiment (DoE) and a designed bending-torsion bench following the ISO 3630-1 standard were used for this investigation. Temperature, holding time, and cooling method were selected as contributing factors, while maximum bending moment, hysteresis size, and stiffness during martensitic transformation were selected as outputs. Regression analysis was performed to estimate the relationship between contributing and output variables to assess how the experimentation fits with the model. The experimental results showed that wires heated at 425 °C for 30 min are more flexible. Moreover, heat treatment temperature is the most critical factor influencing the flexibility and hysteresis size of the NiTi wire followed by the holding time, while the cooling method has a negligible effect. The regression analysis showed that the model is effective at predicting the relationship between contributing factors, bending moment response, and hysteresis size.
The aim of this study was to evaluate the contribution of virtual reality to the conventional analogic training environment and show the complementarity of conventional techniques and virtual reality ...in the learning of dental students. All 88 first‐year dental students at a dental school in France in early 2019 were randomly assigned to one of two groups: group 1 (n = 45) was assigned to cavity preparations on a haptic simulator (Virteasy) and group 2 (n = 43) was assigned to conventional practical work on plastic analogue teeth (Kavo). Following three training sessions, the students in group 1 took a final exam on the same plastic analogue teeth exercise. The results showed improvement in the drilling skill of both groups. The simulator‐trained group (group 1) had similar results to the plastic analogue‐trained group (group 2) in the final test on a plastic analogue tooth. In this study, virtual reality allowed an assessment based on objective criteria and reduced the subjectivity of evaluations conducted on plastic analogue teeth. Considering the saving of supervision and teaching time as well as the material gain offered by virtual reality, the learning methods of haptic simulators are educational options that should be considered by dental educators.
Hepatic sinusoidal obstruction syndrome (HSOS) is a hepatic vascular disease histologically characterized by edema, necrosis, detachment of endothelial cells in small sinusoidal hepatic and ...interlobular veins and intrahepatic congestion, which leads to portal hypertension and liver dysfunction. In the Western world, most HSOS cases are associated with myeloablative pretreatment in a hematopoietic stem cell transplantation setting. Here we report a case of a 54 years old female patient, otherwise healthy, with no history of alcoholic ingestion, who presented with jaundice and signs of portal hypertension, including ascites and bilateral pleural effusion. She had no history of liver disease and denied any other risk factor for liver injury, except Senecio brasiliensis ingestion as a tea, prescribed as a therapy for menopause. Acute viral hepatitis and thrombosis of the portal system were excluded in complementary investigation, as well as sepsis, metastatic malignancy and other liver diseases, setting a RUCAM score of 6. Computed tomography demonstrated a diffuse liver parenchymal heterogeneity (in mosaic) and an extensive portosystemic collateral venous circulation, in the absence of any noticeable venous obstruction. HSOS diagnosis was confirmed through a liver biopsy. During the following-up period, patient developed refractory pleural effusion, requiring hemodialysis. Right before starting anticoagulation, she presented with abdominal pain and distention, with findings compatible of mesenteric ischemia by computed tomography. A laparotomy was performed, showing an 80cm segment of small bowel ischemia, and resection was done. She died one day after as a result from a septic shock refractory to treatment. The presented case was related to oral intake of S. brasiliensis, a plant containing pyrrolidine alkaloids, which are one of the main causes of HSOS in the East, highlighting the risk of liver injury with herbs intake.
The purpose of this study was to evaluate if the use of intraoral scanner analysis could help students to optimise their performance and their self-assessment abilities in prosthetic preparation ...without the teacher's assistance in the preclinical course.
Ninety-five second-year dental students were randomly divided into three groups: Control group (C), CeRec group (CR) and PrepCheck group (PC). Group C only use silicon keys to control the preparation thickness. The students in Group CR analysed their work with Cerec™ software. The Group PC use a pedagogic software (PrepCheck™) which allowed comparison with the "master" preparation. They used control tools preparations for three consecutive training sessions. Then a final assessment session without control tool to evaluate their performance was organised. All preparations were objectively evaluated thanks to stl. analysis software (Geomagic® Control X). Each preparation was compared with the master preparation by defining tolerance ranges. An objective overall score out of 20 was assigned to each preparation according to their degree of correspondence. In addition, a questionnaire was performed to analyse the students' perceptions regarding the use of intraoral camera.
During the assessment session, no significant difference was revealed between the different groups with respect to the students' performance. The comparative analysis between the self-assessment scores and the objective scores using Geomagic® software showed that digital control tools did not help the student to improve their self-assessment abilities without the teacher's assistance.
The intraoral cameras and specific pedagogic software in autonomy could not improve students' performance for teeth preparation and self-assessment abilities in second year. These digital tools facilitate objective feedback on preparation defects, but constructive criticism needs human reflection. The teacher's opinions and advice remain essential to develop their students' performance and self-assessment skills. The use of digital tools must be integrated in dentistry course to develop the interpret of the results and optimise feedback.
Reconstruction of the nasal osseocartilaginous framework is the foundation of successful secondary rhinoplasty.
Achieving this often requires large quantities of cartilage to correct both contour ...deformities and functional problems caused by previous procedures. Satisfactory and consistent long-term results rely on using grafts with low resorption rates and sufficient strength to offer adequate support. Auricular cartilage, irradiated cartilage, and alloplastic materials have all been used as implantable grafts with limited success.
In the senior author's experience (J.P.G.), rib cartilage has proven to be a reliable, abundant, and relatively accessible donor with which to facilitate successful secondary rhinoplasty surgery.
: The authors describe in detail the techniques that they have found to be integral in harvesting rib cartilage grafts for secondary rhinoplasty.
Inflammatory bowel diseases affect mostly young patients and have a huge impact on their quality of life and growing treatment costs. Currently, there are few Brazilian studies concerning their ...epidemiological profile.
The aim of this study was to describe the regional clinical and epidemiological profile of these pathological conditions in Caxias do Sul, Brazil.
Cross-sectional study in Caxias do Sul (RS), Brazil.
A search for patients was conducted in the municipality's special medications pharmacy using the International Classification of Diseases, and medical records were manually reviewed for data collection. Sixty-seven patients were included.
The patients' mean age was 46.5 years and females predominated (71.6%). Ulcerative colitis was the most prevalent disease (70%) and Montreal E3 was the most prevalent presentation. The mean age at diagnosis was 39 years. Most patients had recently undergone colonoscopy (67%). Only five patients (7.4%) had records of hospital admission due to the disease, while 12 (18%) underwent a surgical procedure during follow-up. Sixty patients (89.5%) were using aminosalicylates, while less than one fifth were using immunosuppressants or immunobiological drugs: 19.4% and 14.9%, respectively.
The profile of inflammatory bowel disease patients in this region of Brazil is similar in some characteristics to other published Brazilian data, although it differs in others such as higher frequency of pancolitis. A prospective study on these patients is planned in this region, in order to improve the data quality.
Antimicrobial applications of copper Vincent, Marin; Hartemann, Philippe; Engels-Deutsch, Marc
International journal of hygiene and environmental health,
October 2016, 2016-10-00, 20161001, Letnik:
219, Številka:
7
Journal Article
Recenzirano
Copper has long been known to have antimicrobial activity and is used in drinking water treatment and transportation. It has been recognized by the American Environmental Protection Agency as the ...first metallic antimicrobial agent in 2008. With ongoing waterborne hospital-acquired infections and antibiotic resistance, research on copper as an antimicrobial agent is again very attractive. Many studies have shown that the use of copper surface and copper particles could significantly reduce the environmental bioburden. This review highlights in its first part all the conditions described in the literature to enhance copper antimicrobial activity. Secondly, the different antimicrobial applications of copper in water treatment, hospital care units and public applications are presented. Finally, the future research needs on copper as an antimicrobial agent are discussed.
Abstract
Aims
The endodontic literature reports a lot of comparative study on endodontic instruments, concerning as well their geometry, instrumental dynamics, material, mechanical behavior or heat ...treatment. However, to our knowledge, no study has focused on the influence of endodontic motors on the shaping abilities of endodontic instruments. Thus, the aim of this study was to analyze the influence of the endodontic motors on root canal shaping instruments.
Method
Dual Move (MICRO-MEGA, Besançon, France), Canal Pro CL2i (COLTENE, Alstätten, Suisse), Canal Pro Jeni Motor (COLTENE, Alstätten, Suisse), Ai Motor (WOODPECKER, Guilin, China), Wave One motor (VDW, Postfach, Munich) and Smart A (WOODPECKER, Guilin, China) were pre-clinically compared in continuous rotation and reciprocating motion on a traction/compression bench using resin blocks. Canal shaping in continuous rotation and reciprocating motion were performed with One Curve and One RECI instruments (MICRO-MEGA, Besançon, France), respectively. The penetration/removal forces, making it possible to objectify the cutting effect and screwing effect of the instruments during root canal shaping, were analyzed.
Results
The results showed (i) that endodontic motors influence the mechanical behavior of endodontic instruments, (ii) that the influence of the motors is essentially felt during reciprocating motion and (iii) that the reciprocating angles influence the mechanical behavior of endodontic instruments.
Conclusion
Only endodontic instruments are widely studied in literature while endodontic motors have a direct influence on root canal treatment. This study analyzes the influence of the endodontic motors on root canal shaping instruments. This study tends to demonstrate that Jeni Motor could optimize the mechanical behavior of endodontic instruments.
The authors examined whether the preoperative serum concentrations of cotinine accurately predict the risk of complications in patients undergoing flap reconstruction of head and neck cancer defects.
...Patients with incident stage III or IV squamous cell carcinoma of the head and neck undergoing resection with pedicled or free flap reconstruction were selected from an existing database of 500 patients with squamous cell carcinoma of the head and neck who participated in a prospective epidemiologic study and were reviewed retrospectively. Preoperative serum cotinine concentrations were determined using a competitive microplate immunoassay. Complications were defined as any adverse postoperative wound outcome at either the donor or recipient site.
Eighty-nine patients underwent 101 flap reconstructions. Thirty-seven wound complications occurred in 33 patients. Forty of the 89 patients had a serum cotinine concentration greater than 10 ng/ml; twenty (50 percent) developed postoperative complications, whereas only 13 of 49 patients (27 percent) with a serum cotinine concentration of 10 ng/ml or less developed complications (p = 0.028). The relative risk of wound complications for those with a cotinine concentration greater than 10 ng/ml was approximately double that of patients with a lower cotinine concentration (relative risk, 1.9; 95 percent CI, 1.1 to 3.3). Patients with a cotinine concentration greater than 50 ng/ml had a particularly high risk (relative risk, 2.3; 95 percent CI, 1.1 to 16.7; p = 0.024). The relative risk of wound complications was not significantly associated with self-reported smoking status or history.
A serum cotinine concentration greater than 10 ng/ml may predict an increased risk of wound complication in head and neck flap reconstruction and may serve as an objective, easily measured variable with which to identify patients who may benefit from an aggressive smoking cessation program before surgery.
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