Comparison of combined application treatment with one-visit varnish treatments in an orthodontic population

Objective: To evaluate the effect of chlorhexidine-thymol varnish alone, its combination with chlorhexidine-fluo - ride containing dentifrice and fluoride varnish on oral hygiene and caries prevention in orthodontic patients. Study design: Sixty patients, aged 12-18, with orthodontic fixed appliances were randomly assigned into three groups as follows: Group 1 (n=20): 1% chlorhexidine and 1% thymol varnish (Cervitec ® Plus); Group 2 (n=20): Cervitec ® Plus+ 0.2% chlorhexidine and 0.2% sodium fluoride (900 ppm fluoride) (Cervitec ® Gel)); and Group 3 (n=20): 0.1% fluoride varnish (Fluor Protector ® ). Mutans streptococci (MS), lactobacilli (LB) levels, buffering capacity (BC), visible plaque index (VPI), and gingival bleeding index (GBI) scores were evaluated at four stages: T 0 , before orthodontic bonding; T 1 , one week after orthodontic bonding; T 2 , one week; and T 3 , four weeks after the first application, respectively. Inter and intra group comparisons were made by the Kruskal-Wallis, Mann- Whitney U, Friedman and Wilcoxon Signed-Rank tests with Bonferroni step-down correction ( P< 0.017). Results: Significantly lower MS and LB levels were found in Group 2 than Group 1 (T 2 ) and 3 (T 2 , T 3 ) ( P< 0.017). Groups 1-2 (T 2 ) showed significantly higher BC ( P< 0.017) and lower VPI and GBI ( P< 0.017) scores compared with Group 3. Decreased MS levels at T 2 ( P< 0.017) and T 3 ( P> 0.017) were found in Group1-2 compared with T 0 . Significantly lower LB levels were recorded in Group 2 at T 2 compared with T0 ( P< 0.017) while no significant differences were seen in Group 1 and 3 ( P> 0.017). Conclusions: Addition of Cervitec ® Plus+Cervitec ® Gel combination to the standard oral hygiene regimen may be beneficial for orthodontic patients for maintaining oral health by reducing bacterial colonisation and gingivitis

A case report of brain abscess caused by carbapenem-resistant Klebsiella pneumoniae

The treatment of infections caused by carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains is difficult due to the limited antimicrobial options and high mortality. There are many reports on intracranial infections caused by CR-Kp, but only a few on brain abscesses caused by CR-Kp. Here, we present a case of brain abscess caused by CR-Kp successfully treated with combined antibiotics. A 26-year-old male patient was admitted to our hospital due to high fever and headache. His past medical history includes a surgical intervention due to an acute subdural hematoma, performed at an external healthcare center. After the current diagnosis of cerebral abscess, he underwent two surgeries. During the procedure, multiple cerebral abscesses were drained and capsulotomies were performed under ultrasound guidance. The combination of meropenem and vancomycin was started. The contents of the abscesses were sent to the microbiology and pathology laboratory. On the 3 rd day of treatment, the medical team was informed that CR-Kp grew in an abscess culture. The patient’s treatment was changed to meropenem + colistin + tigecycline. The patient developed electrolyte disturbances during the follow-up and this was considered an adverse effect of colistin. On the 41 st day of treatment, colistin was discontinued, fosfomycin was added, and meropenem and tigecycline were maintained. Treatment was discontinued on the 68 th day, when the patient was discharged. The general condition of the patient, who has been followed up for two years, is satisfactory. The treatment of CR-Kp infections should be individualized, and the pharmacokinetics and pharmacodynamics of antibiotics should be considered in each case

A case report of brain abscess caused by carbapenem- resistant Klebsiella pneumoniae

The treatment of infections caused by carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains is difficult due to the limited antimicrobial options and high mortality. There are many reports on intracranial infections caused by CR-Kp, but only a few on brain abscesses caused by CR-Kp. Here, we present a case of brain abscess caused by CR-Kp successfully treated with combined antibiotics. A 26-year-old male patient was admitted to our hospital due to high fever and headache. His past medical history includes a surgical intervention due to an acute subdural hematoma, performed at an external healthcare center. After the current diagnosis of cerebral abscess, he underwent two surgeries. During the procedure, multiple cerebral abscesses were drained and capsulotomies were performed under ultrasound guidance. The combination of meropenem and vancomycin was started. The contents of the abscesses were sent to the microbiology and pathology laboratory. On the 3rd day of treatment, the medical team was informed that CR-Kp grew in an abscess culture. The patient's treatment was changed to meropenem + colistin + tigecycline. The patient developed electrolyte disturbances during the follow-up and this was considered an adverse effect of colistin. On the 41st day of treatment, colistin was discontinued, fosfomycin was added, and meropenem and tigecycline were maintained. Treatment was discontinued on the 68th day, when the patient was discharged. The general condition of the patient, who has been followed up for two years, is satisfactory. The treatment of CR-Kp infections should be individualized, and the pharmacokinetics and pharmacodynamics of antibiotics should be considered in each case

Effect of Different Steel Fiber Type and Content in Flexural Behavior of Ultra High Performance Fiber Reinforced Concrete

In the research study, the effect of different fiber contents to flexural behavior of the Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) was investigated experimentally. Various prismatic beam specimens with a dimension of 100×100×400 mm including two types of end-hooked steel fibers (aspect ratios: 30/0.55 and 60/0.75) in macro forms and one short straight steel fiber (aspect ratio: 13/0.16) in micro form were produced. The beam specimens corresponding to a total of 18 mixtures having two different volume fractions (1% and 1.5%) were subjected to series of four-point bending tests in accordance with the ASTM standard C 1609. The experimental test results were discussed in terms of the cracking patterns, flexural strengths and toughness (energy absorption ability). In addition, a parametric research was conducted to ensure an appropriate homogenous UHPFRC mixture as well as good workability for the steel fiber volume fraction of 1.0%. Hence the prism and cubic samples were produced by modified of the composition of matrix mixtures (i.e. aggregate, water/binder, cement, superplasticizer). The performance of mixtures was evaluated in terms of the slump flow, T 500, compressive strength and workability. It is apparent from the test results, the use of micro steel fiber significantly improves the flexural performance of the UHPFRC comparing to that of the macro form. It was also noted that the fiber type is decisive in characteristic of the load- deflection curve while the volume content amplifies it with an increasing trend after the first cracking region. When evaluating all UHPFRC matrixes, some of the mixtures under consideration ensured good fiber distribution, workability as well as target compressive strength

Effective Steel Fiber Type Investigation on Ultra High Performance Fiber Reinforced Concrete Beams

Çalışmada, ultra yüksek performanslı lifli beton içeren betonarme kirişlerde eğilme davranışı bakımından etkin çelik lif tipinin deneysel olarak incelemesi yapılmıştır. Bunun için biri lifsiz, diğer dördü farklı çelik lif tipi içeren beş adet 100x150x1500 mm boyutlarında kiriş üzerinde eğilme testleri gerçekleştirilmiştir. Çalışmada 120 MPa üzeri basınç dayanımına sahip, hacimce %1.5 oranında çelik lif içeren beton kullanılmıştır. Lif olarak düz mikro lif tipi (F6), iki adet tek kancalı makro lif tipi (F30 ve F60_1) ve bir adet çift kancalı lif tipi (F60_2) incelenmiştir. Eğilmede etkin çelik lif tipi değerlendirmesi yerdeğiştirme süneklikleri, yük taşıma kapasiteleri ve çatlak özelliklerine göre yapılmıştır. Çalışmada elde edilen sonuçlardan; yük taşıma kapasitesi ve çatlakları sınırlandırma bakımından çift kancalı makro lifin (F60_2), yerdeğiştirme sünekliği bakımından ise düz mikro lifin (F6) en etkin lif olduğu belirlenmiştir.This study investigates the effective steel fiber type on ultra high performance fiber reinforced concrete beams with respect to flexural behavior. Five 100x150x1500 mm reinforced concrete beams, one is non-fiber and the others include four different steel fiber types, were tested in flexure. The concrete used in this study had compressive strength over 120 MPa and included 1.5% steel fibers by volume. Two types of hooked macro steel fibers (F30 and F60_1), double hooked macro (F60_2) and straight micro (F6) steel fibers were investigated. Evaluation of the effective steel fiber type on the flexural behavior were performed in terms of displacement ductility, load bearing capacity and cracking behavior. From the results of the study, it is determined that the most effective steel fiber for load bearing capacity and cracking control is double hooked steel fiber (F60_2) and most effective fiber for displacement ductility is straight micro fiber (F6)

Steel Fiber Use as Shear Reinforcement on I-Shaped UHP-FRC Beams

In the presented paper, the effectiveness of steel fiber use on the shear and flexure behaviors of ultra-high performance concrete (UHPC) beams and the feasibility of steel fibers in place of shear reinforcement were investigated experimentally. In this framework, a total of four I-shaped UHPC beams were produced for a high tensile reinforcement ratio of 2.2%. While two of them were non-fiber UHPC beams with and without the shear reinforcement to show the contribution of steel fibers, the remaining beams were made from the ultra-high performance steel fiber-reinforced concrete (UHP-FRC) having the short straight fibers with 1.5% and 2.5% by volume. The shear and flexural parameters, such as the load&ndash;deflection response, cracking pattern, failure mode, deflection, and curvature ductilities were discussed based on the four-point loading test results. While the reference beam without fiber and shear reinforcement failed by the shear with a sudden load drop before the yielding of reinforcement and produced no deflection capability, the inclusion of steel fibers to the UHPC matrix transformed the failure mode from shear to flexure through the fibers&rsquo; crack-bridging ability. It might be deduced that the moderate level of steel fiber use in the UHP-FRC beams may take the place of shear reinforcement in practical applications

Hybrid fiber use on flexural behavior of ultra high performance fiber reinforced concrete beams

In this study, the flexural behavior of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) beams produced in mono and hybrid forms were investigated experimentally and numerically. Twelve doubly reinforced concrete beams were casted with four different reinforcement ratios representing low to excessive levels. The beams were produced in three groups to study the effects of mono and hybrid steel fiber usages. The first group beams of four are non-fiber beams while the second group contains only short-straight fiber of 13 mm. The last group is composed of hybrid form where the short-straight fiber of 13 mm and the long-hooked fiber of 60 mm were blended together. The beams were subjected to four-point loading, and the parameters of deflection and curvature ductilities, flexural stiffness, flexural moment capacity, cracking behavior and compressive strain were discussed. The test results indicated that the UHPFRC beams with high reinforcement ratios above the limits in current design codes provide remarkable benefits through the fibers' contribution. It can be deduced that the hybrid fiber usage showed better flexural performance, in general, comparing to the mono form. In addition, two numerical approaches were proposed to predict nominal moment capacity of the UHPFRC beams in the mono or hybrid form

Ultra Yüksek Performanslı Lifli Beton İçeren Kirişlerin Eğilme Davranışı

In this study, the effects of using Ultra High Performance Fiber Reinforced Concrete (UHPFRC) on ductility, load bearing capacity, flexural stiffness, failure mode and cracking behavior of reinforced concrete (RC) beams were experimentally investigated. 150x250x2500 mm test beams with rectangular cross sections were used. Straight micro and hooked macro steel fibers were used together in the concrete and average compressive strength of 163 MPa was achieved. A total of nine RC test beams, with and without fibers, consisting of four different tensile reinforcement ratios were tested under four point bending and their flexural behaviors were investigated. The results of the study showed that the use of UHPFRC in the beams provided significant advantages in terms of investigated parameters

Flexural Behavior of Beams with Ultra High Performance Fiber Reinforced Concrete

In this study, the effects of using Ultra High Performance Fiber Reinforced Concrete (UHPFRC) on ductility, load bearing capacity, flexural stiffness, failure mode and cracking behavior of reinforced concrete (RC) beams were experimentally investigated. 150x250x2500 mm test beams with rectangular cross sections were used. Straight micro and hooked macro steel fibers were used together in the concrete and average compressive strength of 163 MPa was achieved. A total of nine RC test beams, with and without fibers, consisting of four different tensile reinforcement ratios were tested under four point bending and their flexural behaviors were investigated. The results of the study showed that the use of UHPFRC in the beams provided significant advantages in terms of investigated parameters