Extended Working Time Research Articles

Shift nurse in implementing shift work schedules and fatigue: A phenomenological study

Nurses who work shifts are professionals, but we don't know much about the conditions and feelings of nurses after becoming nurses. The purpose of the research was to explore the experience of being a shift nurse in implementing shift work schedules and fatigue. Method: The research used a qualitative design with phenomenological approach. The research was conducted in two hospitals used purposive sampling techniques according to predetermined inclusion criteria. The participants were 19 nurses and conducted in-depth interviews . The collected data was subjected to thematic analysis. Results: There were five themes obtained from this research including 1) Shift nurses experience work fatigue which causes their career development opportunities to be reduced; 2) Accompanying doctor visits, workload, number and condition of patients, extended working time due to handovers are the causes of shift nurse fatigue; 3) Nurses experience the risk of SWD and the risk of making human errors while on duty; 4) Changing nurse service schedules and non-ideal service patterns managed by the head of the room risk reducing satisfaction with the service schedule; 5) Shift nurse job satisfaction tends to be low but nurses remain responsible and prioritize working professionally. Conclusion: This research can be concluded that nurses have unique experiences in managing nurse schedule and the impact of fatigue from working as a shift nurse. Nurses are expected to be able to understand which conditions constitute tiring work, and if it is not the nurse's main duties and responsibilities, they can report it to their superiors.

Unique Dye-Sensitized Solar Cell Using Carbon Nanotube Composite Papers with Gel Electrolyte

We propose a unique form of dye-sensitized solar cells (DSSCs), paper DSSCs based on carbon-nanotube (CNT) composite papers, and the use of a gel electrolyte for the paper DSSC. In our previous study, we succeeded in developing the paper DSSC. However, its performance and lifetime were not sufficient. We considered that the problem was the use of liquid-type electrolyte. To improve the performance of the paper DSSC, a gel electrolyte was introduced to increase safety and durability. Here, a polymer gel electrolyte was synthesized using a copolymer of polyethylene glycol (PEG) and polyvinylidene fluoride (PVDF) as a matrix, mixed with iodine and potassium iodide. The resulting paper DSSC had a fill factor (FF, a performance indicator) of 0.248 and a conversion efficiency of 2.43 × 10−5% with an extended working time (lifetime) of more than 110 min. Further modifications were made to the metallic CNT composite paper and the gel electrolyte, resulting in an increased conversion efficiency of 2.02 × 10−3%. This study suggests the potential of gel electrolytes in enhancing the performance of paper DSSCs, providing new insights for their future applications.

Paving block mortars made with mixed waste glass from municipality

To reduce the negative environmental impact of waste glass, this research study aims to incorporate mixed types of municipal waste glass in cement block mortars. The waste glass was first crushed, milled and screened with 18 and 20 meshed sieves to obtain the waste glass powder (WGP). The WGP, grouped into three sizes – small enough to pass through (P20WGP; 95% finer than 125 μm) and too large to pass through a 20 mesh sieve (T20WGP), as well as an equal mix of both sizes (M20WGP) – was used to replace sand in the range 0–100% in the cement block mortar. The specific strength of mortars was enhanced by increasing the WGP content. X-ray diffraction analysis suggested that carbonation at the early age observed in the P20WGP mortars could accelerate strength development. The extended working time test showed that the fresh WGP mortars had the potential for casting in the first 120 min. Different amounts of WGP used in mortars compacted by hand did not produce a significant difference in mechanical properties, suggesting that WGP could replace sand at all percentages. The surface temperature change, as a function of solar irradiated time, of mortar blocks compacted both by hand and hydraulically was similar.

Self-powered pacemaker based on all-in-one flexible piezoelectric nanogenerator

Self-powered pacemakers hold great promise for future clinical translation by virtue of their extended working time and reduced high-risk repeated surgeries. Although self-powered pacemakers have been widely investigated, systematic research on their pacing results in different pacing sites is still lacking, which is crucial for expanding clinical application in the future. Here we design a self-powered pacemaker based on all-in-one piezoelectric nanogenerator (A-PENG) that can harvest biomechanical energy from the cardiac pulsation, enabling valid myocardium pacing and conduction system pacing. The A-PENG prepared by bonding is featured good stretchability, waterproofness, and biocompatibility, which can generate excellent electrical output with human movement. The A-PENG possesses higher stress transfer ability due to tailoring the distribution of the piezoelectric particles, thus enhancing output performance, which can be validated by the comparative experiment and simulation results. The maximum open-circuit (VOC) voltage and short-circuit current (ISC) are 3.1 and 3.0 times higher than routine piezocomposite films. The canine model exhibits valid pacing when the device releases electrical stimulus at right atrium, left ventricle, and His bundle. This work provides a new idea for developing self-powered pacemakers with multifunctional features and an integrated device for in vivo diagnosis and treatment.

Consequences of prolonged sedentary work during the COVID-19 pandemic

Purpose: The COVID-19 pandemic has reduced physical activity and increased the time spent sitting. Combined with the lack of ergonomics at home workplaces, the risk of discomfort has increased, especially around the cervical spine and upper limbs. Evaluation of the mentioned problem is the subject of the study. Methods: The study used an original questionnaire based on the Nordic Musculoskeletal Questionnaire. The analysis used responses from people who reported discomfort in the form of tingling or numbness in the cervical spine, shoulder, elbow and wrist during the pandemic. Statistical analysis of the results was carried out to formulate conclusions. In addition, individual data were presented as percentages. Results: Considering the working time exceeding 8 hours a day, discomfort in the wrist joint area was most often reported among people working remotely (15.1%). Shoulder complex discomfort was the most common symptom (22%) reported by people working more than 8 hours a day, under the age of 31. In young people, the risk of discomfort in the shoulder, hand and cervical spine area increased. Conclusions: Extended working time is conducive to the appearance of symptoms within the hands. In future studies, it will be necessary to analyze the ergonomic factors responsible for this phenomenon.

Impact of Age and Hearing Impairment on Work Performance during Long Working Hours.

Based on demographic prognoses, it must be assumed that a greater number of older workers will be found in the future labor market. How to deal with their possible age-related impairments of sensory functions, like hearing impairment and work performance during extended working time, has not been addressed explicitly until now. The study addresses this interplay. The study was performed on two consecutive days after normal working hours. The 55 participants had to “work” in the study at least three additional hours to simulate a situation of long working hours. The tested measures for (job) performance were: general attention, long-term selective attention, concentration, and reaction time. All of the investigated variables were taken at both days of the study (2 × 2 × 2 repeated measurement design). The results show effects for age, the interaction of hearing impairment and time of measurement, and effects of the measurement time. Older participants reacted slower than younger participants did. Furthermore, younger participants reacted more frequently in a correct way. Hearing impairment seems to have a negative impact especially on measures of false reactions, and therefore especially on measurement time 1. The results can be interpreted in a way that hearing-impaired participants are able to compensate their deficits over time.

A real time ECG data compression scheme for enhanced bluetooth low energy ECG system power consumption

Wearable wireless medical devices have the ability to significantly improve medical care eco-system. Collecting detailed real-time bio-signals data can be straightforward and flexible by equipping patients with wearable devices. The bio-signal sending data through wireless connections which harvest most system power consumption represent one of the main challenges due to battery power limitation. Therefore, reducing the power consumption during wireless data transmitting leads to reduce size and weight of the device which make the patient comfortable especially in long-term medical monitoring. In this study, we present a system level compression scheme for enhancing real-time Bluetooth Low Energy (BLE) Electrocardiogram (ECG) monitoring and recording system. The system is designed and implemented for ECG data capturing and sending it at reduced power transmitting by employing discrete cosine transform (DCT) supported by threshold capability. It is supported by a state-of-the-art system-on-chip (SoC) BLE module as well as the ECG amplifier modules for the amplification process to achieve 6-channel ECG real-time bio-signal which is essential for more accurate and comprehensive diagnosis. A 3-volt Lithium coin cell battery is used to supply the proposed wearable system. The total current consumed by this prototype is further reduced from 2.1 mA (without applying compression algorithm) to 1.5 mA (with enhanced compression algorithm), that leads to extending battery life by 40% from 100 to 140 h. Due to its compact design and an extended period working time, this prototype provides a suitable low-cost solution for long-term monitoring approach in clinical as well as home telemedicine application. The prototype was tested to record various ECG signals for both normal persons and patients. Specifically, it has been tested to capture ten normal cases and 24 arrhythmia and ischemic heart disease in a clinical environment within a specialist heart hospital with satisfactory results.

Comparative Evaluation of varying Photo-polymerization Time on Shear Bond Strength and Microleakage of Four Orthodontic Adhesives: An in vitro Study

ABSTRACTIntroductionHigh early bond strength, extended working time for optimal bracket placement, and easy cleanup of excess adhesive are few advantages of visible light-cure orthodontic adhesives. However, the shorter duration of polymerization may lead to polymer shrinkage and eventually microleakage.ObjectiveTo observe and evaluate shear bond strength (SBS) and microleakage of orthodontic brackets bonded to enamel with four commercially available orthodontic adhesives, cured only from incisal direction at various polymerization times.Materials and methodsA total of 160 bovine incisors were randomly assigned to four groups according to adhesive used. Group I: bonded with Transbond XT (3M Unitek™, USA); group II: Enlight (Ormco, USA); group III: Light Bond (Reliance Ortho, USA); and group IV: Discover (Prime Dental, USA). Each group was further divided into four subgroups of A, B, C, and D according to the polymerization duration of 5, 10, 15, and 20 seconds respectively. The bonded teeth were immersed in dye solution. Brackets were then subjected to SBS test on a Universal testing machine. Surface microleakage was observed with the help of optical stereomicroscope.ResultsThe SBS was obtained within the range of clinically accepted values, with curing time for Enlight at 5 seconds, Transbond XT and Discover at 15 seconds, and Light Bond at 20 seconds. However, Enlight was demonstrated to provide optimum SBS at least curing time: Minimum duration of 5 seconds achieved adequate SBS ~11 MPa SBS for each of Transbond XT and Enlight. The surface microleakage observed is statistically insignificant among the groups.ConclusionFrom a clinical perspective, a composite resin that needs minimum curing time without compromising on the bond strength is most advantageous. The results for SBS tests showed a better performance for Enlight as compared with the other adhesives: it reached its bond strength of optimum value at curing time of 5 seconds.How to cite this articleZanke PN, Patni V, Maskarenj M. Comparative Evaluation of varying Photo-polymerization Time on Shear Bond Strength and Microleakage of Four Orthodontic Adhesives: Anin vitroStudy. J Contemp Dent 2017;7(3):156-160.

Liquid-type AgInS2/ZnS quantum dot-based warm white light-emitting diodes

We here report a warm white light-emitting diode (WLED) by employing the red-emitting liquid layer of AgInS2/ZnS quantum dots (QDs) over the yellow-emitting YAG:Ce phosphor-based WLEDs. Compared to the commercial WLEDs, our liquid-type QD-WLEDs exhibit a color temperature of 3500K and an improved color rendering index of 85. In addition, the experimental results indicate that the liquid structure warm white light device has a higher luminous efficiency of 72.1lm/W and a better color stability against the extended working time in comparison to the solid-type QD-WLEDs.

Development of Air-Stable n-Type Thermoelectric Single-Walled Carbon Nanotubes Doped By Benzimidazole Drivative

Despite the remarkable growth of microelectronics such as wearable and portable devices, remote sensors, etc. on the market in recent years, most of the microelectronics are still powered by batteries that are required to recharge and replace at stated periods. These electronic devices require energy autonomy for an extended working time without the need for the intervention of users. One possible solution for powering these wireless microelectronics without a battery is to harvest energy from the human body by using thermoelectric (TE) generation which generates electricity especially from temperature difference. To generate electricity via Seebeck effect is promising. Seebeck effect is the phenomenon that a temperature difference between hot and cold ends of the TE generators that produces a voltage. The conversion efficiency of TE generators can be evaluated by the dimensionless figure of merit, ZT = S2σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity. TE generator with a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity are expected to get good TE properties. To fabricate the TE devices, p- and n-type materials are necessary and the study of TE materials using inorganic semiconductors such as Bi2Te3 have been done for a long time as they illustrate high performance more than ZT = 1. However, these materials contain rare elements which show toxicity and poor processability. Therefore among the several candidates including conducting polymers, transition metal dichalcogenide and carbon nanotubes (CNTs) single-walled CNTs (SWNTs) are emerged as the promising candidate due to their non-toxicity, processability, abundant resources together with the remarkable electrical conductivity, potentially large Seebeck coefficient and light weight. However, due to the air oxidation, SWNTs only show p-type semiconducting property in air. In the development of the CNT-based TE devices, instability of the n-type CNT has been a central issue, n-type SWNT are easily oxidized due to an electrophilic chemisorption of oxygen on the charge polarization.1 Previously, we reported n-type SWNT by encapsulating cobaltcence to SWNT, however, n-type stability lasts only 30 days in air.2 Therefore, in this study we explored an air-stable n-type thermoelectric material by covering the anion part of the SWNT surface by using cationic molecules as a dopant (n-type dopant). In this strategy, 2-(2-methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzo [d] imidazole (DMBI) was chosen, since it is stable in the atmosphere, forms a stable cationic state by hydride transfer3 and is known as n-type dopant for other carbon materials, such as graphene and fullerene.4 We evaluated the air stability of SWNT doped by DMBI and found that the n-type nature of the DMBI-doped SWNT was stable at least for 90 days at room temperature.5 1) Zhu, X.-Q.; Zhang, M.-T.; Yu, A.; Wang, C.-H.; Cheng, J.-P. J. Am. Chem. Soc. 2008, 130, 2501. 2) Fukumaru, T.; Fujigaya, T.; Nakashima, N. Sci. Rep. 2015, 5, 7951. 3) Wei, P.; Oh, J. H.; Dong, G.; Bao, Z. J. Am. Chem. Soc. 2010, 132, 8852. 4) Wei, P.; Liu, N.; Lee, H. R.; Adijanto, E.; Ci, L.; Naab, B. D.; Zhong, J. Q.; Park, J.; Chen, W.; Cui, Y.; Bao, Z. Nano Lett. 2013, 13 (5), 1890. 5) Nakashima, Y.; Fujigaya, T.; Nakashima, N. in preparation.

Occupational Doses from the use of Thoriated Optical Components.

As a compound of high refractive optical glasses, thorium still is present in some professionally used systems-especially in optical equipment with military use. The possible exposure concerns the head and especially the eye lens, whose radiation sensitivity has been reevaluated. The dose rate measurements of the contribution of beta- and gamma-emission by the nuclei of the decay chain of Th are presented for isolated lenses and for the entire optical system, and the dose quantities H'(0.07) and H*(10) are identified. Exposure scenarios for optical technicians and users are evaluated separately. The levels of dose rates for the inspected optical systems are below those requiring radiation protection measures even for extended working time or unintentional use.

Comparison of root canal sealer distribution in obturated root canal: An in-vitro study.

Background and Objectives:Endodontic sealer is currently regarded with such importance in the root canal treatment that it is often considered to be more important than the core obturating material itself. Sealer with the least film thickness is favorable for minimizing microleakage. The aim of the study is to compare sealer distribution in root canal using three different sealers with three different obturation techniques.Materials and Methods:AH plus, Fuji-1, Tubliseal Extended Working Time (EWT) was placed into the prepared root canals of 90 maxillary central incisors using a lentulospiral. Thereafter, the canals were obturated using three different gutta-percha root filling techniques (single cone, lateral condensation, vertical condensation). Horizontal sectioning was carried out at 3 mm and 6 mm from the apex with a diamond disk. The two specimens thus obtained were examined for sealer distribution using a stereomicroscope and the percentage of sealer coating the perimeter (PSCP) was calculated using a digital imaging system.Results:A significant difference existed in the mean PSCP values of three different sealers (P < 0.000), where Tubliseal (EWT) had the highest PSCP values followed by the AH plus and Fuji-1. Also, between techniques, differences were observed (P < 0.00), where a single cone technique had the highest mean values followed by lateral condensation and vertical condensation. Between the 3 mm and 6 mm sections a non-significant difference was observed (P < 0.945).Conclusion:Tubliseal EWT showed highest PSCP value and Single cone technique showed the higher PSCP value then lateral and vertical condensation technique at 3 mm and 6 mm sections.

Comparative Evaluation of Push-out bond Strength of Three Endodontic Sealers with and without Amoxicillin-An Invitro Study

The purpose of this study was to evaluate the sealing ability of three different root canal sealers with and without amoxicillin, using a push-out bond strength test. Sixty single-rooted extracted human teeth were used for this study. Each tooth was instrumented and irrigated with 5.25% Sodium hypochlorite (NaOCl) and 17% EDTA. The teeth were then divided into six test groups: Gutta percha (GP)/AH Plus (Dentsply, Germany), GP/AH Plus with 10% amoxicillin (TEVA Pharmaceuticals Sellersville, PA), GP/Pulp Canal Sealer EWT (Extended Working Time, SybronEndo Orange, CA), GP/Pulp Canal Sealer EWT with amoxicillin, GP/Apexit Plus, GP/Apexit Plus (Vivadent, Tulsa, US) with amoxicillin. After the sealer was set, the entire root was sectioned into 1 mm thick slices. A push-out bond strength test was performed by using a universal testing machine. The Student's t-test was used to compare the sealer bond strength within the specific sealer test groups and within each sealer at apical, middle and coronal root levels. There was no significant difference between the groups within each sealer (p>0.05) with or without amoxicillin at the same root level. This study demonstrated that the addition of 10% by weight of amoxicillin does not significantly (p> 0.05) change the overall push-out bond strength of three endodontic sealers when compared at the apical, middle, and coronal tooth level.

The effect of immediate and delayed post-space preparation using extended working time root canal sealers on apical leakage

The effect of immediate and delayed post-space preparation using extended working time root canal sealers on apical leakage

SU-E-P-01: Project Schedule for Commissioning of a Synchrotron Based Modulated Scanning Proton Therapy Machine

Purpose: The commissioning of a modulated scanning proton machine, CBCT imaging system, and robotic couch is a challenging project. A coordinated project plan can reduce the required time to commission the system and help facilitate the coordination of work both among physics and with other teams. We have proposed a schedule, listing underlying assumptions, which would accomplish this efficiently. Methods: We used Microsoft Project to create several alternative commissioning schedules for comparison. The commissioning team of five physicists was divided into multiple teams so that work could be accomplished either in parallel or staggered shifts as necessary. Alternative commissioning schedules included a full commissioning of all available energies and options as well as a project plan focused mainly for prostate treatments. Project subsections were grouped so that modifications for changes in project scope or other assumptions could be made easily. Results: The project schedule for full commissioning had a duration of approximately 85 working days while commissioning time for only prostate treatments was 57 days. Detailed beam time requirements and sub‐section completion dates provided necessary information for engineering and other related teams. Time savings in the project schedule was realized in several ways. Staggered shifts were utilized to increase the efficiency in beam measurement time while still allowing for extended working time, splitting shifts if increase in beam time is available. Conclusion: The creation of the project plan has allowed us to have a realistic estimate of the time required to complete the commissioning project along with a list of assumptions made in creating the schedule. This provides a means to track our progress towards completion, quickly assess the impact of any changes to the schedule or difficulties that happen during commissioning, and easily communicate these to interested parties.

Metallurgical analysis and fatigue resistance of WaveOne and ProTaper Nickel–Titanium instruments

The aim of the study was to evaluate cyclic fatigue resistance of two NiTi instruments and to analyse their surface, fractographic and matrix morphology under ESEM/EDS and optical microscopy. WaveOne Primary and ProTaper Universal F2 brand new instruments were subjected to fatigue testing in an artificial canal with 5.0 mm radius and 60° angle of curvature. Seventy-two instruments were divided into three groups (n = 24), according to the selected kinematics: WaveOne using reciprocation (A); ProTaper using reciprocation (B) or rotation (C). Time to fracture was recorded. Data were analysed with ANOVA and Tukey test. ESEM/EDS analysis was conducted on new files to examine surface characteristics and on fractured fragments to identify the fractographic features. Metallographic analysis was performed with optical microscope on new instruments to evaluate alloy properties. Significant differences were found with Group A, which was statistically more resistant to cyclic fatigue (P < 0.05) than the other groups. Surface analysis of new instruments showed both in WaveOne and ProTaper files the presence of deep milling marks. ESEM fractographic analysis of WaveOne showed multiple crack origins with an area of fatigue propagation wider than ProTaper instruments, in which a single crack origin could be detected. EDS analysis confirmed the equiatomic NiTi composition. Metallographic analysis under optical microscope revealed in WaveOne instruments the presence of nano-crystalline martensitic grains embedded in austenite matrix, presence which could not be found in ProTaper files. WaveOne NiTi files revealed higher resistance to fatigue stress, suggesting extended working time in clinical applications.

Abuse of working children and influencing factors, Turkey

ObjectiveThe study was planned as the research of the kind/kinds of abuse and the factors influencing the abuse that the children under 18 who are working full-time at a workplace and enrolled in a vocational training center subjected to. MethodQuestionnaires were administered to 595 apprentices who were attending a vocational training center. ResultsIt was determined that totally 62.5% of the apprentices are subjected to abuse at their workplaces −21.8% physical, 53.6% emotional and 25.2% sexual-, 100% of them are subjected to physical neglect, and 28.7% of them are subjected to emotional neglect. While being subjected to abuse in the family increases all kinds of abuse; divorced parents, being male, low wage of the apprentice increase the possibility of the physical abuse at a work place; the low family income and the extended working time of the apprentice increase the possibility of sexual abuse. Working conditions and workplace characteristics, evaluated within the context of physical neglect are bad in all apprentices. In all kinds of abuse, employer abuse is higher than other people at work. ConclusionIn spite of their being legally protected in theory, the children who are being employed with labor contracts can not benefit from this protection practically at their workplaces. It is seen that most apprentices are subjected to abuse and neglect. Employment of the children is an area which is open to exploitation. It is necessary to prevent the abuse of working children and workplaces should be constantly inspected. The relation between domestic abuse and workplace abuse demonstrates that families occupy the key point in the vicious circle of violence.

Evaluation of sealing ability of a root canal sealer with various antibiotic additives: An in vitro study

Introduction: One of the reasons for persistent endodontic infection is the retention of microorganism on root canal walls. Studies on endodontic prognosis have demonstrated that the addition of antibiotics to the root canal sealer is proven to be beneficial to prevent re-infection and impart antimicrobial property for a longer time. Aims and Objectives: The primary aim of this study is to determine and the secondary aim is to compare the sealing ability of Kerr Pulp Canal Sealer (extended working time) (PCS [EWT]) when used with or without various antibiotic additives viz.; amoxycillin, doxycycline and metronidazole using apical dye leakage method. Materials and Methods: An in vitro study was performed on extracted human teeth, obturated with sealer-antibiotic combinations and sealers alone. Rhodamine-B dye penetration was done for 10 days and the teeth were sectioned and viewed under light microscope; then linear dye penetration was measured and statistically analyzed. Results: Kerr PCS (EWT) showed mean apical leakage of 3.475 mm (P = 0.655, Z = 0.447), whereas PCS (EWT) combined with amoxycillin showed a mean apical leakage of 0.997 mm (P = 0.084, Z = 1.727) showing its clinical significance. PCS (EWT) + amoxycillin showed the best sealing ability with least apical leakage. Conclusion: Addition of antibiotics such as amoxycillin, doxycycline and metronidazole to Kerr PCS (EWT) sealer is recommended as it helps to improve the antibacterial property and the apical sealing ability.Clinical Relevance to Interdisciplinary DentistryBacteria and by-products in the dentinal tubules can cause reinfection of root canal treated teeth.The continuous release of antibacterial agent is desirable to prevent reinfection in root canal treated teeth.This original research hopes to prevent reinfection under the restorations of endodontically treated teeth by the action of additives in root canal sealers and by controlling the microleakage.

The effect of immediate and delayed post-space preparation using extended working time root canal sealers on apical leakage

Background/purposeThe purpose of this study was to compare the effect of different post-space preparation time intervals on the apical sealing ability of filling material using two different extended setting time root canal sealers. Materials and methodsA total of 100 single-canal teeth were incrementally cleaned with crown-down instrumentation using K3 rotary nickel–titanium instruments and randomly divided into four groups. There were 30 teeth in the experimental groups (Groups 1–3) and 10 teeth in the control group (Group 4). We obturated the teeth using a warm gutta-percha vertical compaction technique with pulp canal sealer (Group 1), Tubli-Seal EWT (Group 2), and pulp canal sealer EWT (Group 3). We then stored all the specimens in 100% humidity at 37°C for 1 week. We used heated pluggers to create post space at three different intervals postobturation (i.e., immediately after obturation, on Day 3, and on Day 7), leaving 5-mm gutta-percha filling at the apices. We then immersed the teeth in 2% methylene blue solution for 72 hours, and finally sectioned them longitudinally into two halves. The amount of apical dye leakage was measured under a stereomicroscope. ResultsThe results showed no significant difference (P > 0.05) in dye leakage between the standard and extended working time root canal sealers. Apical leakage tended to increase more severely in Group 1 at the three different intervals was considered. ConclusionExtended working time root canal sealers do not affect microleakage results using a warm gutta-percha vertical compaction technique. The sealing ability of extended working time root canal sealers on high heat conditions is as good as the standard working time root canal sealer during post-space preparation of different intervals.

Abstract No. 183: Radiofrequency targeted vertebral augmentation (RF-TVA) for osteoporotic compression fractures

RF-TVA employs a novel system containing a steerable osteotome for site-specific cavity creation and radiofrequency (RF) modulation of cement viscosity delivered using a hydraulic delivery system. We report a prospective study of patients with acute osteoporotic vertebral compression fractures (VCF) with this system. Between May 2009 and January 2011, 20 patients with 1-3 painful VCFs (confirmed by MRI and pain concordant with index level) who were to receive kyphoplasty treatment were enrolled. Inclusion criteria included age between 50-90, Visual Analogue Pain (VAS) score >4, a moderate (21-40%) or greater Oswestry Disability Index (ODI) score, and 20-90% vertebral compression. VAS and ODI scores were recorded pre-procedure, at discharge, one week, one month, and three months after the procedure. ODI scores were recorded at the same time points except at discharge. Each procedure was performed using this Vertebral Augmentation System. A trocar was placed via a unipedicular approach. . Using a remotely controlled delivery system RF energy was applied tothe PMMA cement as it passed into the delivery cannula. Average patient age was 79.7 ±9.85 years. The mean percentage of collapse was 28 ±13. %. A majority of patients had associated diseases, the most common ones being hypertension (N=14) and coronary artery diseases (N=9). All surgeries were performed within 42 days (av. 13 days) of the patient's reported date of injury. The average procedure time was 18.6 ± 8.95 minutes. No procedure related complications were encountered. No patients required bilateral procedures. The improvement in mean VAS scores from pre-procedure to discharge was 3.4 (p<0.0001). At 1 week, 1 month and 3 months, the improvement in mean VAS score was 3. After three months, the improvement in average ODI scores was significant (34.14%, p < 0.0001). Radiofrequency targeted vertebral augmentation (RF-TVA) is a safe and effective method for treatment of vertebral compression fractures. The use of RF energy, to warm cement immediately prior to entering the patient, results in the unique combination of consistently high viscosity cement useable over an extended working time.