Identification end evaluation of packaging design for internet kiosk depending on feasible on-site service support level

The Internet Kiosks are fast emerging telecommunication products that have a main function to enable public mobility . The estimated market size in 2000 is 2,4 Billion US$worldwide, with prognoses to grow in next 3 years to the level of 7 Billion US$. One of the features offered to the market is plug and play capability, but due to the size and weight of the kiosks, this should be conditionally treated. Some portion of on-site service support at the installation should be considered, the amount of which depends on applied product design and package design solution. Product design and package designs are closely interrelated, and proper solution should result in economically and technically feasible solution. The work includes testing of working models to verify degree of resistance to distribution environment, and appropriate test plan. The shipping weight is 65 kg and quantity 2,000 units/year, and in one solution, the package should be stackable. As the product life (product line) is not expected to be more than tree years, simple test and cost effective method by observations were selected. The feasible and applicable packaging design was determined by analyzing test results, package cost, cost of on-site service, and total cost calculation

Euro-American discussion document on entry and advanced level practice in nuclear medicine

The European Association of Nuclear Medicine Technologist Committee (EANMTC) and the Society of Nuclear Medicine Technologist Section (SNMTS) meet biannually to consider matters of mutual importance. These meetings are held during the SNM and EANM annual conferences. For several years, within these meetings, EANMTC and SNMTS have considered the value of having a Euro-American initiative in defining entry-level and advanced practice competencies for nuclear medicine radiographers (NMRs) and nuclear medicine technologists (NMTs). In June 2009, during the SNM annual conference in Toronto, it was agreed that a Euro-American working party would be established to consider advanced practice. It was recognized that any consideration of a definition for advanced practice would be predicated on an understanding or definition of entry-level practice. As a result, both types of practice would have to be considered. This discussion document outlines some of the background issues associated with advanced practice generally and specifically within nuclear medicine. The primary purpose of this document is to stimulate debate, on a Euro-American level, about the perceived value of advanced practice for NMRs and NMTs within nuclear medicine and to develop an internationally accepted list of entry-level competencies and scope of practice for NMRs and NMTs within nuclear medicine

TESTING THE EFFECTIVENESS OF POLYHEXAMETHYLENE BIGUANIDE ON MICROORGANISMS IN THE ROOT CANAL

Uklanjanje mikroorganizama, upalno promijenjenog i nekrotičnog sadržaja iz endodontskog prostora ključno je za uspjeh endodontskog tretmana. Anatomska građa endodontskog prostora je izrazito kompleksna, stoga sama mehanička obrada nije dovoljna. Potrebna su nam kemijska sredstva koja djeluju na dijelove korijenskog kanala nedostupne endodontskim instrumentima. Takva sredstva, osim što trebaju imati antimikrobni učinak, trebaju biti i biološki sigurna. Svrha ovoga istraživanja bila je utvrditi ima li poliheksametilen bigvanid (PHMB) u koncentraciji od 0,2% antimikrobni učinak na rezistentne mikroorganizme specifične za endodontski prostor zuba unutar nezrelog (48 sati) i zrelog biofilma (4 tjedna), usporediti rezultate s djelovanjem 2,5%-tnog natrijevog hipoklorita (NaOCl) te ispitati citotoksični učinak PHMB-a i NaOCl-a. Zatim je napravljeno istraživanje na mješovitoj kulturi mikroorganizama unutar četiri tjedna starog plaka u kojoj je umjesto P. aeruginosa odabran Staphylococcus epidermidis. Rezultati su uspoređivani s rezultatima dobivenim nakon tretiranja zubi 2,5%-tnim NaOCl-om i 0,2%-tnim klorheksidinom (CHX). Ispitivanje citotoksičnosti PHMB-a i NaOCl-a provodilo se uz pomoć spektrofotometrijskog MTT testa na fibroblastima kineskog hrčka V-79. Rezultati u ovom radu pokazali su da 0,2%-tni PHMB ima jednako antimikrobno djelovanje na E. faecalis, P. aeruginosa i S. epidermidis kao i 2,5%-tni NaOCl, ali bolje djeluje na C. albicans. Obje otopine imaju statistički značajno bolje antimikrobno djelovanje od 0,2%-tnog CHX-a. Rezultati biološkog ispitivanja (citotoksičnost) pokazuju da su oba sredstva citotoksična s tim da PHMB uzrokuje nekrozu, a NaOCl apoptozu V-79 stanica. Za eventualnu kliničku primjenu PHMB-a potrebna su daljnja in vitro i in vivo ispitivanja.The purpose One of the primary objectives in the root canal treatment is to reduce the microbial population in the root canals of infected teeth. This is usually accomplished by mechanical preparation along with the use of irrigant solutions. Antimicrobial irrigant solutions may reach canal ramifications and inaccesible areas and permeate completely through dentinal tubules. This is even more important if we consider the penetration depth of some very resistant and small bacteria such as Enterococcus faecalis which can penetrate dentinal tubules to the depth of 1483.33m (nutrient-rich aerobic condition) or 620m (nutrient-deprived anaerobic conditions). It is present as mushroom shaped microcolonies. The most frequently used irrigant in the treatment of infected root canals is sodium hypochlorite (NaOCl). It has a solvent activity for both necrotic and vital tissues, but at the same time has a cytotoxic effect when injected in the periapical tissues, leaves a bad smell and taste, has a corosive potential and may cause allergic reactions. Polyhexamethylene biguanide (PHMB), active component of Bigvasan IB10 (Arch Chemicals. Inc. UK), (C8H19N5) biocide of biguanidine family, has been developed as a disinfectant for surfaces, objects, instruments. It is also used in wound treatment, promoting wound healing, in mouthwash formulations and in soft lenses care solutions. Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans and Staphylococcus epidermidis are considered to be the most resistant species in infected root canals and are often associated with endodontic treatment failures. The aim of this study was to test ex vivo the effectiveness of 0.2% PHMB and compare it with the effectiveness of 2.5% NaOCl in the elimination of monocultures of resistant microorganisms such as E. faecalis, P. aeruginosa and C. albicans. Our interest also was the effectiveness of those components including 0.2 % chlorhexidine (CHX) on mixed four-week culture of E. faecalis, S. epidermidis and C. albicans. The third part of this thesis was to determine whether PHMB and NaOCl are cytotoxic to cells, and if so, which type of cell death they induce. Ivana Medvedec Mikić Doktorski rad Materials and methods Single-rooted human teeth, extracted for orthodontic or periodontal reasons, were collected. The crowns and the apical parts were removed, the root canals were enlarged with Hedström files to the size 40. Overnight broth cultures of E. faecalis (ATCC 51299), P. aeruginosa (ATCC27853) and C. albicans (clinical isolate) were prepared in tryptic soy broth (Triptic Soy Broth, Difco), specimens for P. aeruginosa, E. faecalis and C. albicans were immerged into 2 ml of broth culture. After the incubation, the root canals were irrigated with saline, and the dentine samples were collected from the inner root canal walls with Hedström files size 50 (sample A). The specimens were treated with 0.2% PHMB, 2.5% NaOCl or with 0.2% CHX. Sample A presented negative control (rinsed only with saline) and sample B presented results after irrigation with 0.2% PHMB and 2.5 % NaOCl. The samples were subcultured on three blood agar plates each. After 48 h incubation at 37 C, visible colonies from appropriated dilutions were counted and the average colony forming units per milliliter (CFU/mL) was calculated and log10-transformed for each sample. The same procedure was done with four-week old culture of E. faecalis, S. epidermidis and C. albicans and the samples were subcultured on selective agars. To determine the cytotoxicity of PHMB and NaOCl, MTT test was used. Two different concentrations of each solution and saline as control were tested on chinese hamster fibroblasts V-79. The concentrations tested on microorganisms were 0.2% and 0.1% for PHMB and 2.5% and 1.25% for NaOCl. In order to reproduce the clinical conditions, contact time was a few seconds, five and ten minutes. Since the cytotoxic assay showed that both, NaOCl and PHMB, caused the cell death in V-79 cells, the following experiment was made to investigate the type of cell death that was induced by those compounds. The loss of membrane integrity was examined by measuring the massive influx of trypan blue in the cells in order to determine if necrosis has occurred. The cells that have lost the membrane integrity, i. e. necrotic cells, were clearly stained blue. The induction of apoptosis was determined by observing the morphological features of the cells treated with NaOCl. The cells were stained with DNA intercalators, acridine orange (AO) and ethidium bromide (EtBr). Acridine orange enters both, the living and the dead cells. Ethidium bromide does not penetrate through the cell membrane of the living Ivana Medvedec Mikić Doktorski rad cells, only through the damaged membrane of the dead cells. The red color of ethidium bromide prevails over green acridine orange so that the dead cells fluoresce red. Thus, simultaneous staining of the cells with acridine orange and ethidium bromide allows distinguishing between the living and the dead cells. Results In the study of unmature biofilm after the treatment with PHMB, P. aeruginosa was eradicated from all the specimens, E. faecalis was also reduced and C. albicans was not grown in seven out of eleven specimens. NaOCl showed weaker results on E. faecalis and P. aeruginosa, especially in the case of C. albicans. As for four-week old culture of E. faecalis, S. epidermidis and C. Albicans, PHMB and NaOCl showed similar results in the case of E. faecalis. CHX showed weaker results on all microorganisms, especially on S. epidermidis. In the case of C. Albicans, the input values were significantly lower than in the bacteria tested, therefore the results should be taken with caution. From the results obtained it is possible to conclude that PHMB shows better antimicrobial effect compared to CHX in the case of both bacteria and the results are comparable to those obtained by the treatment with NaOCl. The obtained results show that these compounds after a few seconds, 5 or 10 minutes of incubation with 0.1% and 0,2% PHMB or 1.25% and 2.5% NaOCl destroyed most of the cells. The types of cell death that were induced with NaOCl and PHMB were different. After rinsing the cells with 0.2% and 0.1% PHMB, all the cells were dead due to the necrosis. After the treatment with 1.25 or 2.5% NaOCl all the cells were dead due to the apoptosis. Significance The results of this study indicate that PHMB in concentration of 0.2% has good antimicrobial effects on microorganisms in immature and mature biofilm. The results are comparable to those obtained by the treatment with NaOCl. Both solutions showed statistically significant better results compared to CHX. Both solutions are cytotoxic to chinese hamster fibroblasts V-79, with a difference in the type of cell death; PHMB caused the necrosis and NaOCl the apoptosis of the cell. Promising antimicrobial results of PHMB suggest further experiments to introduce the PHMB as an endodontic irrigant

TESTING THE EFFECTIVENESS OF POLYHEXAMETHYLENE BIGUANIDE ON MICROORGANISMS IN THE ROOT CANAL

Uklanjanje mikroorganizama, upalno promijenjenog i nekrotičnog sadržaja iz endodontskog prostora ključno je za uspjeh endodontskog tretmana. Anatomska građa endodontskog prostora je izrazito kompleksna, stoga sama mehanička obrada nije dovoljna. Potrebna su nam kemijska sredstva koja djeluju na dijelove korijenskog kanala nedostupne endodontskim instrumentima. Takva sredstva, osim što trebaju imati antimikrobni učinak, trebaju biti i biološki sigurna. Svrha ovoga istraživanja bila je utvrditi ima li poliheksametilen bigvanid (PHMB) u koncentraciji od 0,2% antimikrobni učinak na rezistentne mikroorganizme specifične za endodontski prostor zuba unutar nezrelog (48 sati) i zrelog biofilma (4 tjedna), usporediti rezultate s djelovanjem 2,5%-tnog natrijevog hipoklorita (NaOCl) te ispitati citotoksični učinak PHMB-a i NaOCl-a. Zatim je napravljeno istraživanje na mješovitoj kulturi mikroorganizama unutar četiri tjedna starog plaka u kojoj je umjesto P. aeruginosa odabran Staphylococcus epidermidis. Rezultati su uspoređivani s rezultatima dobivenim nakon tretiranja zubi 2,5%-tnim NaOCl-om i 0,2%-tnim klorheksidinom (CHX). Ispitivanje citotoksičnosti PHMB-a i NaOCl-a provodilo se uz pomoć spektrofotometrijskog MTT testa na fibroblastima kineskog hrčka V-79. Rezultati u ovom radu pokazali su da 0,2%-tni PHMB ima jednako antimikrobno djelovanje na E. faecalis, P. aeruginosa i S. epidermidis kao i 2,5%-tni NaOCl, ali bolje djeluje na C. albicans. Obje otopine imaju statistički značajno bolje antimikrobno djelovanje od 0,2%-tnog CHX-a. Rezultati biološkog ispitivanja (citotoksičnost) pokazuju da su oba sredstva citotoksična s tim da PHMB uzrokuje nekrozu, a NaOCl apoptozu V-79 stanica. Za eventualnu kliničku primjenu PHMB-a potrebna su daljnja in vitro i in vivo ispitivanja.The purpose One of the primary objectives in the root canal treatment is to reduce the microbial population in the root canals of infected teeth. This is usually accomplished by mechanical preparation along with the use of irrigant solutions. Antimicrobial irrigant solutions may reach canal ramifications and inaccesible areas and permeate completely through dentinal tubules. This is even more important if we consider the penetration depth of some very resistant and small bacteria such as Enterococcus faecalis which can penetrate dentinal tubules to the depth of 1483.33m (nutrient-rich aerobic condition) or 620m (nutrient-deprived anaerobic conditions). It is present as mushroom shaped microcolonies. The most frequently used irrigant in the treatment of infected root canals is sodium hypochlorite (NaOCl). It has a solvent activity for both necrotic and vital tissues, but at the same time has a cytotoxic effect when injected in the periapical tissues, leaves a bad smell and taste, has a corosive potential and may cause allergic reactions. Polyhexamethylene biguanide (PHMB), active component of Bigvasan IB10 (Arch Chemicals. Inc. UK), (C8H19N5) biocide of biguanidine family, has been developed as a disinfectant for surfaces, objects, instruments. It is also used in wound treatment, promoting wound healing, in mouthwash formulations and in soft lenses care solutions. Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans and Staphylococcus epidermidis are considered to be the most resistant species in infected root canals and are often associated with endodontic treatment failures. The aim of this study was to test ex vivo the effectiveness of 0.2% PHMB and compare it with the effectiveness of 2.5% NaOCl in the elimination of monocultures of resistant microorganisms such as E. faecalis, P. aeruginosa and C. albicans. Our interest also was the effectiveness of those components including 0.2 % chlorhexidine (CHX) on mixed four-week culture of E. faecalis, S. epidermidis and C. albicans. The third part of this thesis was to determine whether PHMB and NaOCl are cytotoxic to cells, and if so, which type of cell death they induce. Ivana Medvedec Mikić Doktorski rad Materials and methods Single-rooted human teeth, extracted for orthodontic or periodontal reasons, were collected. The crowns and the apical parts were removed, the root canals were enlarged with Hedström files to the size 40. Overnight broth cultures of E. faecalis (ATCC 51299), P. aeruginosa (ATCC27853) and C. albicans (clinical isolate) were prepared in tryptic soy broth (Triptic Soy Broth, Difco), specimens for P. aeruginosa, E. faecalis and C. albicans were immerged into 2 ml of broth culture. After the incubation, the root canals were irrigated with saline, and the dentine samples were collected from the inner root canal walls with Hedström files size 50 (sample A). The specimens were treated with 0.2% PHMB, 2.5% NaOCl or with 0.2% CHX. Sample A presented negative control (rinsed only with saline) and sample B presented results after irrigation with 0.2% PHMB and 2.5 % NaOCl. The samples were subcultured on three blood agar plates each. After 48 h incubation at 37 C, visible colonies from appropriated dilutions were counted and the average colony forming units per milliliter (CFU/mL) was calculated and log10-transformed for each sample. The same procedure was done with four-week old culture of E. faecalis, S. epidermidis and C. albicans and the samples were subcultured on selective agars. To determine the cytotoxicity of PHMB and NaOCl, MTT test was used. Two different concentrations of each solution and saline as control were tested on chinese hamster fibroblasts V-79. The concentrations tested on microorganisms were 0.2% and 0.1% for PHMB and 2.5% and 1.25% for NaOCl. In order to reproduce the clinical conditions, contact time was a few seconds, five and ten minutes. Since the cytotoxic assay showed that both, NaOCl and PHMB, caused the cell death in V-79 cells, the following experiment was made to investigate the type of cell death that was induced by those compounds. The loss of membrane integrity was examined by measuring the massive influx of trypan blue in the cells in order to determine if necrosis has occurred. The cells that have lost the membrane integrity, i. e. necrotic cells, were clearly stained blue. The induction of apoptosis was determined by observing the morphological features of the cells treated with NaOCl. The cells were stained with DNA intercalators, acridine orange (AO) and ethidium bromide (EtBr). Acridine orange enters both, the living and the dead cells. Ethidium bromide does not penetrate through the cell membrane of the living Ivana Medvedec Mikić Doktorski rad cells, only through the damaged membrane of the dead cells. The red color of ethidium bromide prevails over green acridine orange so that the dead cells fluoresce red. Thus, simultaneous staining of the cells with acridine orange and ethidium bromide allows distinguishing between the living and the dead cells. Results In the study of unmature biofilm after the treatment with PHMB, P. aeruginosa was eradicated from all the specimens, E. faecalis was also reduced and C. albicans was not grown in seven out of eleven specimens. NaOCl showed weaker results on E. faecalis and P. aeruginosa, especially in the case of C. albicans. As for four-week old culture of E. faecalis, S. epidermidis and C. Albicans, PHMB and NaOCl showed similar results in the case of E. faecalis. CHX showed weaker results on all microorganisms, especially on S. epidermidis. In the case of C. Albicans, the input values were significantly lower than in the bacteria tested, therefore the results should be taken with caution. From the results obtained it is possible to conclude that PHMB shows better antimicrobial effect compared to CHX in the case of both bacteria and the results are comparable to those obtained by the treatment with NaOCl. The obtained results show that these compounds after a few seconds, 5 or 10 minutes of incubation with 0.1% and 0,2% PHMB or 1.25% and 2.5% NaOCl destroyed most of the cells. The types of cell death that were induced with NaOCl and PHMB were different. After rinsing the cells with 0.2% and 0.1% PHMB, all the cells were dead due to the necrosis. After the treatment with 1.25 or 2.5% NaOCl all the cells were dead due to the apoptosis. Significance The results of this study indicate that PHMB in concentration of 0.2% has good antimicrobial effects on microorganisms in immature and mature biofilm. The results are comparable to those obtained by the treatment with NaOCl. Both solutions showed statistically significant better results compared to CHX. Both solutions are cytotoxic to chinese hamster fibroblasts V-79, with a difference in the type of cell death; PHMB caused the necrosis and NaOCl the apoptosis of the cell. Promising antimicrobial results of PHMB suggest further experiments to introduce the PHMB as an endodontic irrigant

Promjene u zdravlju usne šupljine tijekom rane faze ortodontske terapije

The aim of the study was to assess the influence of fixed orthodontic appliance on Streptococcus (S.) mutans and S. sobrinus counts in orthodontic patients with regard to their previous caries experience (Decayed, Missing and Filled Teeth (DMFT ) index) during the first 12 weeks of orthodontic treatment. Twenty-two patients that satisfied inclusion criteria (healthy systemic and periodontal condition, avoidance of antibiotic therapy and antiseptic mouthwashes in the past three months) were included. All clinical measurements took place prior to and 12 weeks after fixed orthodontic appliance placement, in the following order: 1) stimulated saliva flow (SS); 2) Simplified Oral Hygiene I ndex (OHI -S); and 3) DMFT . The method of polymerase chain reaction (PCR) was used to detect the presence of S. mutans and S. sobrinus at T1 and T2. T-test showed significant increase in DMFT index and SS between T1 and T2. Results also indicated significant improvement in OHI -S index. By use of the PCR method, S. mutans was detected in two patients at T1. At T2, two more patients had S. mutans, but the increase was not statistically significant. Using the same method, S. sobrinus was detected only in two patients at T2. In conclusion, fixed orthodontic appliances did not induce statistically significant changes in caries microflora even in the presence of enhanced oral hygiene habits.Svrha istraživanja bila je utvrditi utjecaj fiksnih ortodontskih naprava na broj kariogenih bakterija Streptococcus (S.) mutans i S. sobrinus u ortodontskih pacijenata s obzirom na njihov kariogeni status (indeks DMFT ) tijekom prvih dvanaest tjedana ortodontske terapije. U istraživanju je sudjelovalo 22 ispitanika koji su zadovoljili kriterije za uključenje: uredno opće i parodontno zdravlje, izbjegavanje antiseptika za ispiranje usne šupljine i antibiotika u prethodna tri mjeseca. Sva klinička mjerenja napravljena su prije (T1) i 12 tjedana nakon (T2) postavljanja fiksne ortodontske naprave sljedećim redoslijedom: 1) količina stimulirane sline (SS), 2) Simplified Oral Hygiene Index (OHI -S) i 3) DMFT . Reakcija lančane polimeraze (PCR) je korištena za otkrivanje prisutnosti S. mutans i S. sobrinus prilikom T1 i T2. T-test je pokazao značajan porast indeksa DMFT i SS između T1 i T2. Rezultati također pokazuju značajno poboljšanje indeksa OHI -S. Koristeći PCR metodu S. mutans je otkriven kod dvoje ispitanika na T1. Nakon 12 tjedana fiksne ortodontske terapije došlo je do porasta broja ispitanika kod kojih je otkriven S. mutans, ali porast nije bio statistički značajan. Istom metodom S. sobrinus je otkriven tek u dvoje ispitanika na T2. U zaključku, tijekom prvih 12 tjedana fiksne ortodontske terapije nije došlo do statistički zančajne promjene u kariogenoj mikroflori. Primjena individualnih edukativnih i preventivnih mjera oralne higijene može spriječiti nastanak štetnih nuspojava tijekom fiksne ortodontske terapije

Prevalence of Third Molars and Pathological Changes Related to Them in Dental Medicine

The purpose of this study was to determine the prevalence of third molars in terms of respondents’ age. Furthermore it was desired to determine the extent of the manifestation of pathological changes, such as caries, apical lesions, and al- veolar bone resorption. This study was based on 500 OPGs of patients from the Faculty of Dentistry, University of Zagreb. Patients were divided into seven age groups. The total number of molars, the number of cavities on remaining molars, the quality of endodontic treatment and the evaluation of their performance and presence of periapical lesions was ana- lyzed. As a part of the periodontal status, the number of inadequate fillings, the number of damaged furcations and bone resorption was analyzed. The statistical analysis was performed by means of STATISTICA 7 statistical package (Stat- Soft, Tulsa, USA). The correlation between the total number of molars and the age of patients was analyzed by means of Spearman’s correlation to the level of significance of 0.05. The number of first, second and third molars significantly de- creased in higher age groups. The prevalence of caries in third molars as compared to first and second molars was gener- ally lower, third molars were endodontic treated at least. Assessment of involved furcations showed that the lowest per- centage of 8% was found in third molars. The majority of all remaining molars had bone resorption of 1–3 mm

COSMUS in school, community and diversity

UIDB/04647/2020 UIDP/04647/2020publishersversionpublishe

A measurement of irradiance of light-curing units in dental offices in three Croatian cities

Aim To determine irradiance of light-curing units (LCUs) in dental offices in three Croatian cities and to compare irradiance values with the age and model of LCUs. Methods Private and public dental offices in three most prominent cities in Croatia (Rijeka, Split and Zagreb) were included in this study. In total, 195 LCUs were tested, using radiometer Ivoclar Bluephase Meter 2 for irradiance (mW/cm2 ). The minimum acceptable value was set at 400 mW/cm2 . The age, model and difference between declared and measured irradiance of the LCUs were also determined. Of the total of 195 LCUs, 190 (98%) were LED (light-emitting diode) and 5 (2%) were QTH (quartz-tungsten – halogen). Results The mean age of tested LCUs was 4.43±3.4 years; the oldest was in Rijeka, 5.2±3.8 years. The overall mean irradiance for all three cities was 806.4 mW/cm2 (p=0.0004). Of all LCUs, 11.3% were considered clinically unacceptable with irradiance of less than 400 mW/cm2 . Of all tested LCUs 42% (p=0.0005) had a 30% lower value of irradiance than the manufacturer of the LCU declared. In 73% tested LCUs, there was a matching between measured and declared irradiance. The age and model of LCUs had the most significant impact on irradiance. Conclusion The most commonly used LCU included in dental offices was LED. Mean irradiance was good enough to secure adequate polymerization of resin-based materials. Irradiance decreases with usage time of LCU

The Effect of Polyhexamethylen Biguanide on Microorganisms in Root Canal

Svrha rada: Željela se ispitati djelotvornost 0,2-postotnog poliheksametilenova bigvanida (PHMB) u eliminaciji Enterococcus faecalis, Pseudomonas aeruginosa i Candida albicans te ga usporediti s učinkovitošću 2,5-postotnog natrijeva hipoklorita (NaOCl). Materijali i metode: Na četrdeset osam jednokorijenskih zuba uklonjeni su krune i apikalni dijelovi te su korijenskih kanali instrumentirani Hedström strugaËima do veličine 40. Šesnaest uzoraka inokulirano je bujonskom kulturom E. faecalis (ATCC 51299), P. aeruginosa (ATCC27853) i C. albicans (klinički izolat). Nakon 48-satne inkubacije i ispiranja fiziološkom otopinom uzeti su uzorci dentina iz korijenskih kanala Hedströmovim iglicama veličine 50 i to prije ispiranja 0,2-postotnim PHMB-om i 2,5-postotnim NaOCl-om i nakon toga postupka. Uzorci su zatim preneseni u epruvete s 2 mL sterilne fiziološke otopine i deseterostrukim razrjeđenjem, te su prebačeni na krvni agar nakon 30 sekundi vorteksiranja. Nakon 48-satne inkubacije na 37 ° C prebrojene su bakterijske kolonije po mililitru (CFU/ml). Za statističku analizu korišten je Kruskal-Wallisov test (p <0,05) . Rezultati: Nakon tretmana poliheksametilenovim bigvanidom iz svih je uzoraka uklonjena P. aeruginosa, E. faecalis iz devet od jedanaest, a C. albicans iz sedam od jedanaest uzoraka. NaOCl je bio manje učinkovit od PHMB-a u djelovanju na E. faecalis (p = 0,630) i P. aeruginosa (p = 0,138), a posebice na C. albicans (p = 0,01). Zaključak: Broj E. faecalis i P. aeruginosa učinkovito smanjuju 0,2-postotni PHMB i 2,5-postotni NaOCl. Na C. albicans bolji antimikrobni učinak ima 0,2-postotni PHMB od 2,5-postotnog NaOCl-a. Daljnja istraživanja potrebna su kako bi se ustanovila učinkovitost PHMBa na zreli biofilm i njegova biokompatibilnost.Objective of work: The objective of this study was to test the effectiveness of 0.2% polyhexamethylen biguanide in the elimination of Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans and compare it with effectiveness of 2.5% sodium hypochlorite. Materials and Methods: Crown and apical portion of forty- eight single-rooted human teeth was removed and the root canals instrumented with Hedström files up to size 40. Sixteen specimens were inoculated with an overnight broth culture of E.faecalis (ATCC 51299), P.aeruginosa (ATCC27853) and C.albicans (clinical isolate). After 48 h incubation and irrigation with saline, dentine samples were collected from root canal walls with Hedström files size 50 before and after irrigation with 0.2% PHMB and 2.5% NaOCl followed by irrigation with neutralizer and saline. Samples were put into vials containing 2 mL of sterile saline and tenfold dilution, and plated on blood agar after 30 s vortexing. Colony forming units (CFU) were counted after 48 h incubation at 37ºC. For statistical analysis Kruskal-Wallis test (p<0.05) was used. Results: After treatment with PHMB P.aeruginosa was eradicated from all samples, E.faecalis was also reduced and C.albicans was not grown in seven out of eleven samples. NaOCl was less effective than PHMB on E.faecalis (p=0.630) and P.aeruginosa (p=0.138), especially in case of C.albicans (p=0.01). Conclusions: 0.2% PHMB effectively reduced the number of E.faecalis and P.aeruginosa as well as 2.5% NaOCl). On C.albicans 0.2% PHMB showed better antimicrobial effect than 2.5% NaOCl. Further studies will be necessary to determine PHMB’s effectiveness on mature biofilm and its biocompatibility

Self Assessment of Dental students’ Perception of Learning Environment in Croatia, India and Nepal

Cilj: Željela se procijeniti percepcija studenata dentalne medicine iz različitih okolina za učenje u Hrvatskoj, Indiji i Nepalu. Postupci: Istraživanje je provedeno tijekom akademske godine 2016./17. Ukupno je sudjelovalo 849 studenata dentalne medicine – 188 iz Hrvatske, 373 iz Indije i 288 iz Nepala. Oni koji nisu ispunili upitnik nisu uzeti u obzir. Primijenjen je Upitnik za studente dentalne medicine o okolini za učenje (engl. Dental Student Learning Environment Survey – DSLES) koji se sastojao od 55 pitanja svrstanih u 7 kategorija. Njima su se mjerile percepcije fleksibilnosti, interakcija među studentima, emocionalno ozračje, potpora, stečeno iskustvo, organizacija i širina interesa. U statističkoj analizi podataka korišten je Kolmogorov-Smirnovljev test. Kruskal-Wallisova neparametrijska ANOVA također je upotrijebljena u testiranju razlika između zemalja. Post hoc analiza obavljena je s pomoću Ranksovih tablica i medijanskoga testa. Rezultati: Odgovorilo je 26,9 % studenata. Značajne razlike između zemalja nađene su za sve varijable DSLES upitnika (Kruskal-Wallis, p < 0,01). Medijanski test također je pokazao značajne razlike za sve varijable DSLES-a (p < 0,01). Kategorije s najvišim srednjim vrijednostima ocjena su interakcije među studentima u Indiji i Nepalu te emocionalno ozračje u Hrvatskoj. Zaključak: Studenti u Hrvatskoj ocijenili su svoj fakultet samo ocjenama odličan i dobar, a njihovi kolege u Indiji i Nepalu bili su kritičniji. Unatoč različitim okolnostima u trima zemljama, fleksibilnost je identificirana kao područje slabosti u svim tim sustavima obrazovanja.Aim: The aim of this study was to assess dental students’ perception of different learning environment in India, Nepal and Croatia. Methods: The study was conducted during a period of academic year 2016/17. A total of 849 dental students participated in the study. There were 188 respondents from Croatia, 373 from India, and 288 from Nepal. Non-responders were not followed up. The Dental Student Learning Environment Survey (DSLES) was used which consisted of 55 items subdivided into seven scales. The scales measured the following perceptions: Flexibility, ‘Student-to-Student Interactions, Emotional Climate, Supportiveness, Meaningful Experience, Organization and Breadth of Interest. Statistical analysis of the data utilised the Kolmogorov Smirnov test. The Kruskal-Wallis “non-parametric ANOVA” was also used to test the differences between the countries. A post hoc analysis was performed using Ranks tables and the Median test. Results: The response rate was 26.9%. Significant differences between the countries were found for all DSLES variables (Kruskal-Wallis, p<0.01). The Median test also showed significant differences between the countries for all DSLES variables (p<0.01). The scales with the highest mean values were ‘Student-to-student interactions’ in India and Nepal, and the ‘Emotional Climate’ in Croatia. Conclusions: Students in Croatia rated their school only with grades excellent and good, while their colleagues in India and Nepal were more critical. Despite the different settings in three countries, ‘Flexibility’ was identified as the area of weakness in all three educational systems