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Introduction Lower respiratory tract secretions (LRTS) like sputum and tracheal aspirates are frequently sent to the microbiology laboratory from patients with various respiratory pathologies. Improper collection techniques can lead to false-positive results, resulting in improper therapy. Aim of the study To determine the percentage of contaminated samples sent to the microbiology laboratory, to establish the prevalence of Candida spp. in non-contaminated samples and therefore, the presence of Candida spp. originating in lower respiratory tract infections. Material and Methods A 10-year data survey was conducted to assess the differences in Candida prevalence from contaminated versus non-contaminated samples, assessed and categorised by Bartlett grading system, and to emphasise the importance of quality control for potentially contaminated samples. The data were analysed according to gender, age, referring departments, and the species of Candida. For the statistical analysis, Kruskal-Wallis and Fisher tests were used, and the alpha value was set for 0.5. Results The prevalence of Candida spp. in all analysed samples was 31.60%. After excluding the contaminated samples, the actual prevalence was 27.66%. Of all sputum samples, 31.6% were contaminated. Patients aged more than 40 years old were more prone to provide contaminated sputum samples. C. albicans is more prevalent in non-contaminated sputum samples. In both sputum and tracheal aspirates, the chances of identifying a single species are higher than the chances of identifying multiple species. Conclusions The study emphasises the importance of assessing the quality of sputum samples because of the high number of improperly collected samples sent to the microbiology laboratory.

Introduction The World Health Organization (WHO) identified a novel coronavirus, originating in Wuhan, China, in December 2019, as a pneumonia causing pathogen. Epidemiological data in Romania show more than 450.000 confirmed patients, with a constant number of approximately 10% admission in intensive care unit. Method A retrospective, observational study was conducted from 1st March to 30th October 2020, comprising 657 patients, confirmed as having COVID-19, and who had been admitted to the intensive care unit of the Mures County Clinical Hospital, Tîrgu Mures, Romania, which had been designated as a support hospital during the pandemic. Patients who presented at admission or developed abnormal liver function tests in the first seven days of admission, were included in the study; patients with pre-existing liver disease, were excluded. Results The mean (SD) age of patients included in the study was 59.41 (14.66) years with a male: female ratio of 1.51:1. Survivor status, defined as patients discharged from the intensive care unit, was significantly associated with parameters such as age, leukocyte count, albumin level, glycaemia level (p Conclusions Liver injury expressed through liver function tests cannot solely constitute a prognostic factor for COVID-19 patients, but its presence in critically ill patients should be further investigated and included in future guideline protocols.

Following the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, design, development, validation, verification and implementation of diagnostic tests were actively addressed by a large number of diagnostic test manufacturers. This paper deals with the biases and sources of variation which influence the accuracy of diagnostic tests, including calculating and interpreting test characteristics, defining what is meant by test accuracy, understanding the basic study design for evaluating test accuracy, understanding the meaning of Sensitivity, Specificity, Positive Predictive Value and Negative Predictive Value, and evaluating them numerically, and the ROC curve (or Receiver Operating Characteristic ) and the Area under the Curve (AUC).

Introduction Critically ill patients in intensive care units are at high risk of dying not only from the severity of their illness but also from secondary causes such as hospital-acquired infections. USA national medical record-data show that approximately 10% of patients on mechanical ventilation in an intensive care unit developed ventilator-associated pneumonia. Polymyxin B has been used intravenously in the treatment of multi-drug resistant gram-negative infections, either as a monotherapy or with other potentially effective antibiotics, and the recent international guidelines have emphasised the use of nebulised polymyxin B together with intravenous polymyxin B to gain the optimum clinical outcome in ventilator-associated pneumonia cases caused by multi-drug resistant gram-negative infections. Methods One hundred and seventy-eight patients with ventilator-associated pneumonia due to multi-drug resistant K. pneumoniae were identified during the study period. Following the inclusion and exclusion criteria, 121 patients were enrolled in the study and randomly allocated to two study groups. Group 1 patients were treated with intravenous Polymyxin B plus nebulised polymyxin B (n=64) and Group 2 patients with intravenous Polymyxin B alone (n=57). The study aimed to compare the use of Polymyxin B plus its nebulised form to polymyxin B alone, in the treatment of MDR-K. pneumoniae associated ventilator-associated pneumonia in critically ill patients. Results In Group 1, a complete clearance of K. pneumoniae was found in fifty-nine patients (92.1%; n=64) compared to forty patients (70.1%, n=57) in the Group 2 (P

Background The study aimed to investigate the changes in nosocomial infection density after patients were transferred to the intensive care unit (ICU) of a new-build hospital. Methods The types and rates of nosocomial infections were obtained for a one-year period retrospectively before leaving the old hospital premises and for a one-year periods after moving into the new hospital. The intensive care unit in the “old” premises was comprised of a 17-bedded hall, and thirty-three nurses shifted to work forty-eight hours a week, with each nurse assigned to provide care for two patients. The intensive care unit in the “new” premises consisted of single rooms, each with twenty-eight beds. Results The median nosocomial infection density decreased from 23 to 15 per 1000 in-patient days. The catheter-related urinary tract infection rate decreased from 7.5 to 2.6 per100 catheter days. Conclusions Treatment of patients in the new hospital resulted in a decrease in nosocomial infection density.

Introduction Variations in the expression of vascular endothelial growth factor (VEGF) could be used as a biomarker in critically ill patients with sepsis and septic shock. Inflammation potently upregulates VEGF-C expression via macrophages with an unpredictable response. This study aimed to assess one of the newer biomarkers (VEGF-C) in patients with sepsis or septic shock and its clinical value as a diagnostic and prognostic tool. Material and methods The study involved 142 persons divided into three groups. Group A consisted of fifty-eight patients with sepsis; Group B consisted of forty-nine patients diagnosed as having septic shock according to the Sepsis -3 criteria. A control group of thirty-five healthy volunteers comprised Group C. Severity scores, prognostic score and organ dysfunction score, were recorded at the time of enrolment in the study. The analysis included specificity and sensitivity of plasma VEGF-C for diagnosis of septic shock. Circulating plasma VEGF-C levels were correlated with the APACHE II, MODS and severity scores and mortality. Results The mean (SD) plasma VEGF-C levels in septic shock patients (1374(789) pg./m), on vasopressors at the time of admission to the ICU, were significantly higher 1374(789)pg./mL, compared the mean (SD) plasma VEGF-C levels in sepsis patients (934(468) pg./mL); (p = 0.0005, Student’s t-test.) Plasma VEGF-C levels in groups A and B were shown to be significantly correlated with the APACHE II (r = 0.21, p = 0.02; r = 0.45, p = 0.0009) and MODS score (r = 0.29, p = 0.03; r = 0.4, p = 0.003). There was no association between plasma VEGF-C levels and mortality [p = 0.1]. The cut-off value for septic shock was 1010 pg./ml. Conclusions VEGF-C may be used as a prognostic marker in sepsis and septic shock due to its correlation with APACHE II values and as an early marker to determine the likelihood of developing MODS. It could be used as an early biomarker for diagnosing patients with septic shock.

H1N1 is seen in tropical countries like India, occurring irrespective of the season. Complications of the disease are frequently encountered and there is little in the way or guidelines as to the how these should be managed. The treatment of one such complication, a recurrent pneumiomediastinum is the subject of the current paper. The management followed guidance for the treatment of a similar condition known as primary spontaneous pneumomediastinum, an uncommon condition resulting from alveolar rupture-otherwise known as the Macklin phenomenon.

Summary Objective To measure Total Light Energy (TLE) Transmission through six makes of ceramic orthodontic brackets alone and bracket-plus-adhesive samples, using the MARC™-Resin Calibrator (RC). Methods Six makes, three each monocrystalline (M) and polycrystalline (P) were used; PureSapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), and Dual Ceramic (P). The Ortholux™ Light Curing Unit (LCU) was used to cure the orthodontic adhesive Transbond™XT. The LCU's tip irradiance was measured and TLE transmitted through the ceramic bracket was obtained, then adhesive added to the bracket, and transmitted TLE measured through bracket-plus-adhesive samples. The LCU was set at five seconds as recommended for curing adhesive through ceramic brackets. Results Mean tip irradiance was 1859.2 ± 16.2 mW/cm2. The TLE transmitted through brackets alone ranged 1.7 to 3.9 J/cm2, in the descending order: Ghost > Pure Sapphire > Reflections > Mist > SPA Aesthetics > Dual Ceramic. The TLE transmitted through bracket-plus-adhesive samples ranged 1.6 to 3.7 J/cm2, in the descending order: Ghost > Mist > Reflections > Pure Sapphire > SPA Aesthetics > Dual Ceramic. TLE was reduced with the addition of adhesive (range −0.1 to −0.7 J/cm2). There was a significant difference for Pure Sapphire, Reflections, and Mist (P Conclusion Light energy attenuation through ceramic orthodontic brackets is make-dependent, with no overall difference between monocrystalline and polycrystalline brackets. Light energy is further attenuated with the addition of resin-based orthodontic adhesive.

Resume Objectif Mesurer la transmission de l’energie lumineuse totale (ELT) au travers d’echantillons de six marques d’attaches orthodontiques en ceramique avec et sans adhesif a l’aide du systeme de mesure MARC™-Resin Calibrator (RC). Methodes Six marques, trois monocristallines (M) et trois polycristallines (P), ont ete testees : Pure Sapphire (M), SPA Aesthetic (M), Ghost (M), Mist (P), Reflections (P), et Dual Ceramic (P). La lampe Ortholux™ Light Curing Unit (LCU) a ete utilisee pour polymeriser l’adhesif Transbond™XT. Le produit de l’irradiance (flux de radiation arrivant sur la surface mWatt/cm2) mesuree a l’extremite de l’embout de la lampe et du temps d’exposition (secondes) representent l’energie totale transmise au travers de l’attache ceramique (mJoules/cm2) ; ensuite l’adhesif a ete applique sur l’attache et l’ELT a ete mesuree au travers de l’attache ceramique avec l’adhesif. La lampe a ete reglee sur cinq secondes pour la polymerisation de l’adhesif au travers des attaches en ceramique, conformement aux recommandations du fabricant. Resultats L’irradiance moyenne mesuree a l’embout etait de 1859,2 ± 16,2 mW/cm2. Les valeurs d’ELT transmise au travers des attaches nues variaient de 1,7 a 3,9 J/cm2 dans l’ordre degressif suivant : Ghost > Pure Sapphire > Reflections > Mist > SPA Aesthetics > Dual Ceramic. Les valeurs d’ELT transmise au travers des attaches-plus-adhesif variaient de 1,6 to 3,7 J/cm2, dans l’ordre degressif suivant : Ghost > Mist > Reflections > Pure Sapphire > SPA Aesthetics > Dual Ceramic. L’ELT etait reduite apres application de l’adhesif de −0,1 a −0,7 J/cm2. Une difference significative a ete observee pour Pure Sapphire, Reflections et Mist (p Conclusion L’attenuation de l’ELT se produisant a travers les attaches ceramique, quelle que soit la structure monocristalline ou polycristalline, est « marque-dependante ». En outre, l’adjonction d’adhesif orthodontique a base de resine aggrave cette attenuation.

Introduction Critically ill patients in intensive care units are at high risk of dying not only from the severity of their illness but also from secondary causes such as hospital-acquired infections. USA national medical record-data show that approximately 10% of patients on mechanical ventilation in an intensive care unit developed ventilator-associated pneumonia. Polymyxin B has been used intravenously in the treatment of multi-drug resistant gram-negative infections, either as a monotherapy or with other potentially effective antibiotics, and the recent international guidelines have emphasised the use of nebulised polymyxin B together with intravenous polymyxin B to gain the optimum clinical outcome in ventilator-associated pneumonia cases caused by multi-drug resistant gram-negative infections. Methods One hundred and seventy-eight patients with ventilator-associated pneumonia due to multi-drug resistant K. pneumoniae were identified during the study period. Following the inclusion and exclusion criteria, 121 patients were enrolled in the study and randomly allocated to two study groups. Group 1 patients were treated with intravenous Polymyxin B plus nebulised polymyxin B (n=64) and Group 2 patients with intravenous Polymyxin B alone (n=57). The study aimed to compare the use of Polymyxin B plus its nebulised form to polymyxin B alone, in the treatment of MDR-K. pneumoniae associated ventilator-associated pneumonia in critically ill patients. Results In Group 1, a complete clearance of K. pneumoniae was found in fifty-nine patients (92.1%; n=64) compared to forty patients (70.1%, n=57) in the Group 2 (P

Despite the significant development and advancement in antibiotic therapy, life-threatening complication of infective diseases cause hundreds of thousands of deaths world. This paper updates some of the issues regarding the etiology and treatment of abdominal sepsis and summaries the latest guidelines as recommended by the Intra-abdominal Infection (IAI) Consensus (2017). Prognostic scores are currently used to assess the course of peritonitis. Irrespective of the initial cause, there are several measures universally accepted as contributing to an improved survival rate, with the early recognition of IAI being the critical matter in this respect. Immediate correction of fluid balance should be undertaken with the use of vasoactive agents being prescribed, if necessary, to augment and assist fluid resuscitation. The WISS study showed that mortality was significantly affected by sepsis irrespective of any medical and surgical measures. A significant issue is the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in the clinical setting, and the reported prevalence of ESBLs intra-abdominal infections has steadily increased in Asia. Europe, Latin America, Middle East, North America, and South Pacific. Abdominal cavity pathology is second only to sepsis occurring in a pulmonary site. Following IAI (2017) guidelines, antibiotic therapy should be initiated as soon as possible after a diagnosis has been verified.

Introduction Hungry bone syndrome (HBS) refers to the rapid, profound, and prolonged hypocalcaemia associated with hypophosphatemia and hypomagnesaemia, and is exacerbated by suppressed parathyroid hormone (PTH) levels, which follows parathyroidectomy in patients with severe primary hyperparathyroidism (PHPT) and preoperative high bone turnover. [1] Case report This report concerns a dialysed patient who underwent surgical treatment for secondary refractory hyperparathyroidism. Haemodialysis was carried out pre-operatively, and subsequently, a total parathyroidectomy with auto-transplantation of parathyroid tissue in the sternocleidomastoid muscle (SCM) was performed. Rapid and progressive hypocalcaemia symptoms developed during the second day postoperatively. Acute cardiac symptoms with tachyarrhythmia, haemodynamic instability and finally asystole occurred, which required cardiopulmonary resuscitation (CPR). The ionic calcium level was 2.2 mg/dL being consistent with a diagnosis of HBS. A second cardiac arrest unresponsive to CPR followed an initial period of normal sinus rhythm. Death ensued shortly after. Before death, the ionic calcium was 3.1 mg/dL. Conclusion HBS, after parathyroidectomy in patients with secondary hyperparathyroidism (SHPT), may be severe, prolonged and sometimes fatal. Generally, HBS symptomatology is that of a mild hypocalcaemia. It can, however, include heart rhythm disturbances with haemodynamic alterations requiring intensive care measurements and even cardiopulmonary resuscitation. A close clinical and laboratory post-parathyroidectomy monitoring of dialysed patients is of the utmost importance.

Background Much concern appears to exist as to the scope and content of contemporary dental school programmes, with the oft-cited criticism being made that dental graduates are 'no longer as good as they used to be'. Aim The aim of this project was to survey the views of dentists – both new graduates and more established practitioners – on aspects of their own dental school training they felt had been deficient as well as commenting on what aspects of dental school education they would like to see improved/enhanced in current times. Methods An invitation to complete an Internet-based questionnaire was emailed to the Fellows and Members of the Faculty of General Dental Practice (UK). Topics in the questionnaire included the respondent's own dental education history, how well they felt their dental school training had covered certain clinical and non-clinical topics; and their opinions on areas they felt should be included in contemporary dental school programmes. Results Six hundred and forty-nine responses were received from 3,348 emailed invitations (response rate = 19.4%). Sixty-one percent (395) of respondents were qualified for 10 years or more. Among clinical skills and techniques, a majority of respondents reported they felt they had not had sufficient teaching/training in dental school in surgical endodontics (76%), conscious sedation (72%), root surface debridement (71%), fixed orthodontic appliances (68%), porcelain veneers (63%), implants (56%) and posterior composites (53%). If designing a new dental school programme, the most common topics respondents would seek to include/increase were business and practice management (21%), communication skills (including patient management and leadership skills) (10%), and increased clinical time and experience (8%). Conclusions The findings of this project are of interest and relevance to those working with student dentists and young dental practitioners. A greater emphasis is needed on the teaching of certain non-clinical subjects such as business and communication skills, while within clinical subjects there is need to refine and expand teaching in identified areas such as exodontia and endodontics.

Sepsis represents one the main cause of death in patients admitted to the intensive care. Biomarkers offer an alternative approach to the diagnostic and prognostic evaluation and improve the outcomes. Angiopoietin 2 (Ang-2) and Tyrosine kinase 2 (Tie-2) are biomarkers which may be involved in sepsis, Ang-2 being responsible for vascular remodelling while Tie-2 is their endothelial receptor. The aim of the study: To assess the Ang-2, Tie-2 and Ang-2/Tie-2 ratio serum levels in septic and non-septic patients and to investigate the independent value of circulating Ang-2, Tie-2, and Ang-2/Tie-2 ratios as predictors of prognosis in critically ill medical patients. Study design: The study included 74 adults admitted to an intensive care unit (ICU). The patients were separated in two groups: Group A [sepsis: n=40] and Group B [no-sepsis: n= 34] patients. Serum levels of Ang-2 and Tie-2 were determined in the first 12 hours after admission and were correlated with ICU severity scores, APACHE II, SOFA and SAPS and with the death rate. Results: Group A gave significantly higher values (p=0.01), for serum Ang-2 (11.07±9.21 ng/ml) compared to Group B (6.18±5.28 ng/ml). The level of Tie-2 was also higher (11.03±5.12 ng/ml) in Group A compared to Group B (9.46±4.99 ng/ml) (p=0.19). In Group A, the Ang-2/Tie2 ratio showed higher values than Group B (p=0.02). There was a positive association between severity scores (APACHE II, SAPS, and SOFA) and Ang-2, and Ang-2/ Tie-2 ratio, but not for Tie2. Conclusions: In our study Ang-2 and Ang-2/Tie-2 ratio serum levels had independent diagnostic value in patients with sepsis, as measured on admission.

Introduction: Manufactures claim that recently introduced bulk fill materials (BFM) can be cured adequately in 4 mm increments. This requires adequate light energy to be transmitted through the material to ensure adequate polymerization at the bottom of the increment. Aim: To compare the total light energy transmission through three BFMs and bottom/top (B/T) surface Vickers hardness (VH) when cured with single-peak versus dual-peak LED LCUs. Methods and Materials: Samples (n=5) of two viscous BFMs, Tetric EvoCeram® Bulk Fill X-tra fil® [XF] flowable SureFil, were prepared. A conventional RBC, Tetric EvoCeram® was used as a control. Using MARC® RC, the irradiance delivered to top surface of samples was adjusted to 1200 mW/cm2. Samples were cured with singlepeak EliparTM S10 or dual-peakBluephase® G2 for 10 seconds and irradiance transmitted to the bottom surface measured. Samples were stored for 24 hours, prior to VH measurements B/T VH ratios were calculated. Statistically analysed used oneway ANOVA (α=0.05). Results: There was no statistically significant difference for B/T total energy transmission between materials except XF with EliparTM S10 (P0.05) when materials were cured with single-peak versus dual-peak LCU’s, XF>SDR>TEC>TBF. TBF alone, did not reach the generally accepted B/T VH of 80%. Conclusions: Both single-peak and dual-peak LCU’s were equally effective for curing the studied bulk fill materials. Manufacture’s recommended total energy delivered to the top surface may not always be sufficient for effective curing.

To quantify light energy transmission through two bulk-fill resin-based composites and to measure the top to bottom surface Vickers hardness ratio (VHratio) of samples of various incremental thicknesses, using either a single-wave or dual-wave light curing unit (LCU).Tetric EvoCeram Bulk Fill (TECBF) and SonicFill (SF) were studied. Using MARC-RC, the irradiance delivered to the top surface of the samples 2, 3, 4 and 5 mm thick (n= 5 for each thickness) was adjusted to 800 mW/cm2 for 20 seconds (16 J/cm2) using either a single-wave, Bluephase or a dual-wave, Bluephase G2 LCUs. Light energy transmission through to the bottom surface of the specimens was measured at real time using MARC-RC. The Vickers hardness (VH) was determined using Vickers micro hardness tester and the VHratio was calculated. Data were analyzed using a general linear model in Minitab 16; α= 0.05.TECBF was more translucent than SF (P0.05). The mean VHratio was higher than 80% in 2, 3 and 4 mm increment thickness for both materials (except for 4 mm TECBF when cured with the dual-wave Bluephase G2). SF showed significantly higher VH ratio than TECBF at all different thickness levels (P0.05), except at the 2 mm level (P0.05). TECBF showed significantly greater VH ratio when cured with the single-wave Bluephase than when using the dual-wave Bluephase G2 (P0.05).The transmission of light energy through to the bottom surface and the VHratio are material dependent. Although TECBF is more translucent than SF, it showed lower VHratio compared to SF when cured with dual-wave Bluephase G2.

To compare the total light energy transmission (J/cm2) through bulk-fill composite materials (BFMs) and Vickers hardness (VH) using a single-peak light curing unit (LCU) using two curing regimens.Samples (n= 5) of viscous BFMs, Tetric EvoCeram Bulk Fill (TBF), X-tra fil (XF), and flowable BFMs, SureFil SDR (SDR), and X-tra base (XB) were prepared in 4 mm deep rings. The control was Tetric EvoCeram (TEC), a conventional composite. Using MARC-RC, the irradiance delivered to the top surface of the samples was adjusted to either 800 mW/cm2 for 20 seconds (16 J/cm2) or 1,600 mW/cm2 for 10 seconds (16 J/cm2). Samples were stored post-irradiation at 22 ± 2°C for 24 hours. Top and bottom-surface VH were measured and Bottom/Top (B/T) VH ratios were calculated. Data were analyzed using one-way ANOVA (α= 0.05).Total energy transmission for all materials ranged from 1.0 J/cm2 (6.1%) to 2.7 J/cm2 (16.9%). There was a statistically significant difference for total energy transmission to the bottom surface, more being transmitted at 800 mW/cm2 x 20 (P0.001). XB and TEC were significantly different, with higher B/T VH ratio when cured at 800 mW/cm2 x 20 seconds (P0.001). There was no statistically significant difference for TBF, XF and SDR (P0.05) with either curing regimen.The degree of cure was material-dependent and increasing curing time may be more important than LCU tip irradiation values. Manufacturer's recommended total energy regimen may not always be adequate for effective curing. Some bulk-fill materials, containing additional photo-sensitivity to lower wave lengths, may be adequately cured using a single-peak LCU.

Background There is a lack of data on polymerization of resin-based materials (RBMs) used in paediatric dentistry, using dual-peak light-emitting diode (LED) light-curing units (LCUs). Objective To evaluate the degree of conversion (DC) of RBMs cured with dual-peak or single-peak LED LCUs. Methods Samples of Vit-l-escence (Ultradent) and Herculite XRV Ultra (Kerr) and fissure sealants Delton Clear and Delton Opaque (Dentsply) were prepared (n = 3 per group) and cured with either one of two dual-peak LCUs (bluephase® G2; Ivoclar Vivadent or Valo; Ultradent) or a single-peak (bluephase®; Ivoclar Vivadent). High-performance liquid chromatography and nuclear magnetic resonance spectroscopy were used to confirm the presence or absence of initiators other than camphorquinone. The DC was determined using micro-Raman spectroscopy. Data were analysed using general linear model anova; α = 0.05. Results With Herculite XRV Ultra, the single-peak LCU gave higher DC values than either of the two dual-peak LCUs (P

Polymerization of Resin Based Composites (RBCs) initiated by a light curing unit activating photoinitiators. Different RBCs require different light energy levels for proper curing. Manufacturers are now producing RBCs with more than one initiator and not all of these will be properly polymerised with blue LED lights. An added problem is that manufacturers do not always indicate the type of photoinitiators in their materials. This review discusses the importance of matching the spectral output of LCUs to the absorption spectra of RBCs and the consequences of spectral mismatch. Resin based composites (RBCs) were first introduced in the 1960s1 and with development of effective and reliable dentine bonding systems2, have been used routinely as a filling material for both anterior and posterior teeth. The early RBCs were either chemically cured two component materials or photo-initiated materials that used UV initiators in the beginning and then transitioned to visible light initiators such as camphorquinine which was introduced in 1978.3 The first report of a light curing material was of an ultraviolet (UV) cured fissure sealant.4 However, due to the limited penetration depth of the UV light and the potential health hazards, this system was quickly abandoned. The advancement of science yielded light curing materials which contributed to a significant clinical progress over the UV and chemically cured RBCs.4 Additional advancements to direct RBC restoration materials included luting agents for ceramic restorations, pit and fissure sealants and resin modified glass ionomers. Polymerization in an RBC is initiated by a light curing unit (LCU); this technology is based on the use of photoreactive systems that absorb light irradiation from the LCUs at appropriate wavelength. Then the photoinitiators contained in the RBCs, absorb the incoming photons from the LCU and the monomers in the molecular structure become excited and in that active state, there is a change from monomers into a polymer network6. The success of this technology hinges on matching the spectral emission of the LCU with the requirements of the photoinitiator system to convert the monomers into a polymer network. The amount of activated photo initiator depends on the concentration of photoinitiator in the material, the number of photons to which the material is exposed and the energy of the photons (wavelength), the latter depending on the curing light.6 The most common photoinitiator in dental materials today is camphorquinone, which has a peak activity around 470 nanometres.6 The factors affecting polymerization include filler type, size and loading, the thickness and shade of the restorative material, the effectiveness of light transmission (eg. light guide tips being free from debris and scratches), exposure time, distance of the light source from the restorative material and light intensity.7 It is important to note that the photoinitiator activation occurs at specific wavelengths, in other words, the optimum efficiency is obtained when the peak absorptivity of the photoinitiator corresponds with the spectral emission from the LCU. Commercially available curing units have different light intensities and light sources, with energy levels in QTH, LED and other LCUs ranging from 300 to more than 2000 mW/cm.

Introduction. Postoperative sensitivity in restorative dentistry can be related to preparation trauma, dentin adhesives' ability to seal open dentinal tubules, deformation of restorations under occlusal stresses and microleakage. Objective. The study assessed possible reduction in postoperative sensitivity with low shrinkage compared to conventional composites using different bonding agents and the influence of the operator skill on the incidence of postoperative sensitivity. Methods. Nine hundred and sixty permanent premolars and molars with primary carious lesions from patients 21 to 40 years old were used. Cavities 2 to 3 mm deep and with margins in enamel were prepared by four operators. Two operators had five years (A and B) and two had over 20 years (C and D) of clinical experience. Teeth were divided into eight groups each contained 120 restorations: (1) Els®+James-2 (original formula), (2) Els®+James-2 (new formula), (3) Els®+Excite, (4) InTenSe®+James-2 (original formula), (5) InTenSe®+James-2 (new formula), (6) InTenSe®+Excite, (7) Tetric Ceram®+Excite, and (8) Point 4®+OptiBond Solo Plus. At 14 days postoperatively, two independent operators, who did not take part in the clinical procedure, assessed postoperative teeth sensitivity using special questionnaires. Data were analyzed using non-parametric chi-square, Mann-Whitney and ANOVA tests. Results. Group 8 showed significantly higher score than the other groups. Less postoperative sensitivity was reported with two low-shrinkage composites (groups 2, 3, and 5) but with no significant difference. There was no statistical difference between groups 1, 2, 3, 4, 5, 6 and 7. Operator A had the highest postoperative sensitivity score compared to the other three. Conclusion. Conventional composite material Point 4® with its bonding agent caused significantly more postoperative sensitivity than low shrinkage composites combined with different adhesives. Operator skill influenced the incidence of postoperative sensitivity., Uvod. Posle postavljanja kompozitnih ispuna može da se javi postoperaciona osetljivost izazvana preparacionom traumom, sposobnošću adhezivnog sistema da hermetički zatvori dentinske kanaliće, deformacijom pod okluzalnim opterećenjem ili prodorom bakterijskih toksina. Cilj rada. Cilj istraživanja je bio da se ispita da li je osetljivost zuba manja kod kompozita s malom kontrakcijom u poređenju s konvencionalnim kompozitima i odgovarajućim adhezivnim sistemima, kao i uticaj veštine stomatologa na incidenciju postoperacione osetljivosti zuba. Metode rada. Na 960 premolara i molara stalne denticije s primarnim karijesom, pacijenata starosti od 21 godine do 40 godina, preparisani su kaviteti dubine 2-3 mm s rubovima u gleđi. Čitavu proceduru su obavila četiri specijalista stomatologije, od kojih su dva imala pet (A i B), a druga dva više od 20 godina kliničkog iskustva (C i D). Zubi su svrstani u osam grupa od po 120 uzoraka prema korišćenom kompozitnom i adhezivnom sistemu: 1) Els®+James-2; 2) Els®+James-2 (nova formula); 3) Els®+Excite; 4) InTenSe®+James-2; 5) InTenSe®+James-2 (nova formula); 6) InTenSe®+Excite; 7) Tetric Ceram®+Excite; i 8) Point 4®+OptiBond Solo Plus. Dve nedelje posle intervencije dva nezavisna stomatologa (koja nisu učestvovala u kliničkoj proceduri) ocenjivala su posebnim upitnicima postoperacionu osetljivost zuba. Podaci su analizirani neparametrijskim c2, Man-Vitnijevim (Mann-Whitney) i ANOVA testom. Rezultati. U osmoj grupi utvrđena je statistički značajno češća postoperaciona osetljivost nego u ostalim grupama zuba. Nije bilo statistički značajne razlike između grupa 1, 2, 3, 4, 5, 6 i 7. Kompoziti sa nižom polimerizacionom kontrakcijom izazvali su manju postoperacionu ostetljivost, ali bez statističke značajnosti razlika (grupe 2, 3 i 5). Kod stomatologa A javljala se statistički značajno češće postoperaciona osetljivost nego kod ostala tri. Zaključak. Tip kompozitnog materijala s odgovarajućim adhezivnim sistemom i spretnost stomatologa utiču na učestalost pojave osetljivosti zuba posle restauracija srednje dubokih kaviteta II klase.

The aims of this study were to assess the light energy transmission and Vickers hardness (VH) ratio of two bulk-fill resin-based composites (RBCs) (Tetric EvoCeram and Filtek) cured at different distances between the light curing unit's (LCU) tip and the surface of the restoration (T-S) using either a Bluephase G2, Bluephase® 'turbo tip' or Bluephase Style LCU. Samples were cured from the top at T-S distances of 2mm, 6mm and 10mm for 20 seconds. A MARC-Resin-Calibrator™ recorded the transmitted irradiance reaching the bottom of the sample, in real time. The VH was measured at the top and bottom after 24h of dark storage. Both the total light energy (TLE) transmitted through the samples and their VH ratios were reduced with increasing T-S distance. At 10mm T-S distance, the VH ratio values of samples cured with Bluephase G2 LCU were significantly greater than the samples cured with the other LCUs while the samples cured with Bluephase® 'turbo tip' showed the lowest values. It can be concluded that TLE transmitted through bulk-fill RBCs and their VH ratio reduces with increasing T-S distance but the rate of decline is LCU dependent. Bluephase G2 was associated with the smallest light attenuation.

To evaluate the total light energy (TLE) transmission through three types of ceramic brackets with, bracket alone and with the addition of orthodontic adhesive, at different exposure durations, and to compare the microhardness of the cured adhesive.Three different makes of ceramic brackets, Pure Sapphire(M), Clarity™ ADVANCED(P) and Dual Ceramic(P) were used. Eighteen specimens of each make were prepared and allocated to three groups (n = 6). MARC(®)-resin calibrator was used to determine the light curing unit (LCU) tip irradiance (mW/cm(2)) and TLE (J/cm(2)) transmitted through the ceramic brackets, and through ceramic bracket plus Transbond™ XT Light Cure Adhesive, for 5, 10 and 20 s. Vickers-hardness values at the bottom of the cured adhesive were determined. Statistical analysis used one-way analysis of variance (ANOVA); P = 0.05.TLE transmission rose significantly among all samples with increasing exposure durations. TLE reaching the adhesive- enamel interface was less than 10 J/cm(2), and through monocrystalline and polycrystalline ceramic brackets was significantly different (P 0.05). Pure Sapphire(M) showed the highest amount of TLE transmission and Vickers-hardness values for 5, 10 and 20 s.Following manufacturer's recommendations, insufficient TLE may be delivered to the adhesive: increasing the exposure durations may be required when adhesive is cured through ceramic brackets. Clinicians are advised to measure the tip irradiance of their LCUs and increase curing time beyond 5 s. Orthodontic clinicians should understand the type of light curing device and the orthodontic adhesive used in their practice.

Aim This study compared the effect of seven different disposable cross-infection control sleeves on the total energy delivered (J/cm2) by four different dental light-curing units (LCUs). Methods Four LCUs and seven disposable sleeves (six proprietary brands and a general-purpose cellophane wrap) were used. Anterior and posterior tooth position was included as a third factor. Total energy delivered was measured for each LCU without a sleeve (control) and with each sleeve and for each tooth position. Curing time was 10 seconds, as recommended by the LCU manufacturers. Measurements were taken 10 times for each sleeve/LCU/tooth position and means (SD)calculated. Data were analysed using three-way analysis of variance (ANOVA). The null hypothesis was that none of the sleeves would, at a 0.1% level, significantly affect the total energy delivered. Results All sleeves significantly reduced the total energy delivered ( PConclusions Sleeves significantly reduce the total energy delivered compared to unsleeved LCUs, but to a degree that may not be clinically important. Cling film reduced total energy delivered to a significantly lesser extent than did proprietary bands of sleeve. In order to determine adequacy of delivered total energy, sleeved LCUs should be tested prior to clinical use.