Klinička ispitivanja restauracija cervikalnih nekarijesnih lezija

The therapy of non-caries cervical lesions is an important problem in restorative dentistry, for the ambiguous aetiology, clinical diagnoses and for the selection of restorative procedure. Aim: The aim of this work was to clinically check the efficiency of non-caries cervical lesions restoration depending on materials used for restorative fillings. Materials and methods: Clinical researches covered 62 teeth of different morphology group at the patients of both gender and of different age. The restoration of gingival lesions, with no previous preparation, was done with composite adhesive system SINGLE BOND/Valux Plus (3M) (30 teeth) and with campomer DYRACT AO (Dentsplay) (32 teeth). The fillings were estimated on the checkups which took place on 3,6 and12 months applying modified criteria according to Ridge and Cvar. Results: The acquired results showed that after 3 to 6 months there were no changes at none of examined parameters and all the fillings got maximal mark A. 12 months latter, in the two cases with composite filling, the marginal adaptation got the mark B (607%). The marginal adaptation at two teeth restored with compomers got the mark B (6.3%) Postoperative sensitiveness phenomenon, marginal discoloration and secondary caries weren’t registered in none of the cases after the observation period of 12 months. Conclusion: For the restoration of non-caries cervical lesions, composite materials with suitable adhesive system and the new generation of compomers could be used.Terapija nekarijesnih cervikalnih lezija je značajan problem u restaurativnoj stomatologiji, zbog nejasne etiologije, kliničke dijagnoze ali i izbora restaurativne procedure. Cilj: Cilj ovog rada je bio da se klinički proveri efikasnost restauracija nekarijesnih cervikalnih lezija zuba u zavisnosti od korišćenih materijala za restaurativne ispune. Materijal i metod: Klinička ispitivanja su obuhvatila 62 zuba različitih morfoloških grupa kod pacijenata oba pola i različite starosti. Restauracija gingivalnih lezija, bez prethodne preparacije, urađena je kompozitnim adhezivnim sistemom SINGLE BOND/Valux Plus (3M) (30 zuba) i kompomerom DYRACT AP (Dentsplay) (32 zuba). Ispuni su procenjivani na kontrolnim pregledima posle 3, 6 i 12 meseci primenom modifikovanih kriterijuma po Ridge-u i Cvar-u. Rezultati: Dobijeni rezultati su pokazali da posle 3 i 6 meseci nije bilo promena na ispunima ni kod jednog ispitivanog parametra i svi ispuni su ocenjeni maksimalnom ocenom A. Posle 12 meseci, u dva slučaja ispunjenih kompozitima, ivična adaptacija je ocenjena ocenom B (6,7%). Ivična adaptacija je i u dva zuba restaurisanih kompomerima ocenjena ocenom B (6,3%). Pojava postoperativne osetljivosti, ivične diskoloracije i sekundarnog karijesa nije registovana ni u jednom slučaju posle observacionog perioda od 12 meseci. Zaključak: Za restauraciju nekarijesnih cervikalnih lezija mogu se koristiti kompozitni materijali sa odgovarajućim adhezivnim sistemima i novije generacije kompomera

Mogućnost prevencije postoperativne osetljivosti u zuba restaurisanih kompozitnim ispunima

Introduction: Postoperative sensitivity is a common problem in patients after placement of resin-based composite (RBC) restorations. Aim: The of this study was to evaluate clinical efficacy of oxalate desensitizer BisBlock in the prevention of postoperative sensitivity after placement of RBC restorations. Materials and Methods: This clinical study was conducted at Belgrade University School of Dentistry Department of Restorative Dentistry and Endodontics. The study comprised 31 patients, both sexes, aged 18 - 32. In each patient, two class II cavities were prepared in premolars (62 cavities) and restored with RBCs. One restored tooth in each patient was treated with BisBlock (experimental group) while another served as control. In the restorative procedure, Single Bond (3M ESPE) was used as the adhesive and teeth were restored with Valux Plus (3M ESPE) RBC. Sensitivity evaluation was performed at day 1, day 4 and day 7 after restoration and comprised sensitivity on thermal and osmotic stimuli as well as sensitivity during mastication. Results: The obtained results revealed statistically significant decrease of postoperative sensitivity in experimental (3.23%) than control group (16.14%). .Uvod: Postoperativna osetljivost je čest problem kod pacijenata nakon postavljanja kompozitnih ispuna na zubima. Cilj ovog istraživanja je bio da se proveri klinička efikasnost oksalatnog desenzibilizatora BisBlock u prevenciji postoperativne osetljivosti posle postavljanja kompozitnih ispuna na bočnim zubima. Materijal i metod: Kliničko istraživanje je sprovedeno na Klinici za Bolesti zuba Stomatološkog fakulteta Univerziteta u Beogradu. U istraživanje je uključen 31 pacijent, osoba oba pola, uzrasta od 18 do 32 godine. Kod svakog pacijenta su urađena dva kaviteta druge klase na premolarima (62 kaviteta) i restaurisani kompozitnim ispunima. Jedan restaurisani zub svakog ispitanika je tretiran BiSBlock-m (ekperimentalana grupa) dok je drugi poslužio kao kontrolna grupa. U restaurativnoj proceduri kao adhezivno sredstvo je korišćen Single Bond (3M ESPE) a zubi su restaurisani kompozitnim materijalom Valux plus(3M ESPE). Procena osetljivosti je vršena posle prvog, četvrtog i sedmog dana od restauracije, ispitivanjem osetljivosti na termičke i osmotske nadražaje i ispitivanjem osetljivosti na pritisak u toku mastikacije. Rezultati: Dobijeni rezultati su pokazali da je upotrebom desenzibilizatora BisBlock-a došlo do statisticki značajnog smanjenja pojave postoperativne osetljivosti kod eksperimentalne (3.23%.) u odnosu na kontrolnu grupu (16.14%).

Uticaj pH vrednosti rastvora natrijum-hipohlorita na uklanjanje razmaznog sloja

Introduction. Canal irrigation is an important segment of endodontic treatment. The aim of this study was to assess the efficacy of 0.5% NaOCl solutions of different pH values on smear layer removal. Material and Methods. Thirty-two freshly extracted single rooted teeth with gangrenous pulp were used in the study. The samples were divided into four groups of eight teeth in each. Four solutions of 0.5% NaOCl having pH values 5, 7, 9 and 12 respectively, were used during chemomechanical instrumentation with hand instruments and using step back technique. SEM analysis was done to assess the quality of smear layer removal in apical, middle and coronal part of root canal. Presence and quantity of smear layer and detritus was quantified using the scale from 1 to 5. Results. SEM analysis results showed similar results for 0.5% NaOCl solutions of different pH values in root canal cleaning with no statistically significant differences. Conclusion. The most effective cleaning root canal was achieved with 0.5% NaOCl solution of pH 5.Uvod. Irigacija kanala je značajan segment svakog endodontskog lečenja zuba. Cilj ovog rada je bio da se proveri efekat čišćenja zida kanala korena zuba nakon ispiranja rastvorom od 0,5% natrijum-hipohlorita (NaOCl) različitih pH vrednosti. Materijal i metode rada. Kao materijal korišćena su 32 sveže izvađena jednokorena zuba sa gangrenoznom pulpom. Uzorci su svrstani u četiri grupe od po osam zuba. Za ispiranje tokom mehaničko-medikamentne obrade tzv. step-back tehnikom i ručnim endodontskim instrumentima primenjena su četiri rastvora koncentracije od 0,5% NaOCl sa puferovanim rastvorima čija je pH vrednost bila 5, 7 i 9, odnosno nepuferovanim rastvorom pH vrednosti 12. SEM analizom je proveren kvalitet čišćenja zida kanala od razmaznog sloja u apeksnom, srednjem i koronarnom delu kanala korena. Procena zastupljenosti i količine razmaznog sloja i detritusa vršena je ocenjivanjem na skali od 1 do 5. Rezultati. Rezultati SEM analiza su pokazali slično dejstvo različitih pH vrednosti rastvora NaOCl u čišćenju kanala korena zuba bez statističke značajne razlike. Zaključak. Najefikasnije čišćenje kanala korena ostvareno je 0.5% rastvorom NaOCl čiji je pH 5

Extreme Precipitation Events in Serbia: Defining the Threshold Criteria for Emergency Preparedness

Considering recent weather events in Serbia (especially the floods in 2014), a need has arisen for research that would help in identifying extreme weather phenomena. Therefore, the aim of this paper is to determine the thresholds above which intense precipitation can be considered as extreme precipitation events in Serbia. In this study, we determined the frequency of precipitation occurring at an intensity above the threshold of an extreme phenomenon (1961-2015), as well as the frequency of precipitation occurring at or above the absolute daily maximum in the reference period (1961-1990). The study sample included daily rainfall observations from 28 stations from the national meteorological network in Serbia. Applying a decile method, all the stations recording precipitation above the threshold of dangerous phenomena on the same day are classified into the corresponding decile. The threshold value was determined as the average value of the extreme annual precipitation in the analyzed period. The cases that are due to the high prevalence listed in the last decile are considered extreme. The results showed that the critical number of observation points above which an event is considered extreme precipitation event is 6.21, and a warning of the danger could be ensured only in the case of neighboring stations in the network. The threshold of extreme precipitation events for the individual stations ranges up to 130 mm. The obtained results might be used to mitigate the effects of extreme precipitation events in Serbia in the future

Refractive indices of unfilled resin mixtures and cured composites related to color and translucency of conventional and low-shrinkage composites

This study correlated the refractive indices (RIs) of unfilled resin mixtures and resin-based composites (RBCs) with color and translucency of conventional and low-shrinkage RBCs. Unfilled resin mixtures based on different ratios of conventional monomers Bisphenol A-glycidyl-methacrylate (BisGMA)/triethyleneglycol-dimethacrylate (TEGDMA) and urethane-dimethacrylate (UDMA)/TEGDMA and a low-shrinkage monomer FIT-852 (FIT, Esstech Inc.)/TEGDMA were used to prepare model RBCs, containing 30 wt % of the organic matrix and 70 wt % of silanated barium-glass fillers (n=1.553, Esstech Inc.). The RIs of resins were measured on an ABBE refractometer, those of cured RBCs using the Becke-line method in immersion oils. Color and translucency were determined using an AvaSpec-2048 (Avantes BV) spectrometer. The RIs of unfilled resin mixtures decreased with increasing amounts of TEGDMA. Cured RBCs had higher RIs than their respective resin mixtures. BisGMA-based composites were more translucent with significantly lower L* values than FIT- and UDMA-based RBCs. The RIs of unfilled resins positively correlated with cured RBCs (p=0.001), as did the RIs with translucency (p=0.001) and color (p=0.008). Resin mixtures and corresponding RBCs based on UDMA and its modified low-shrinkage version, FIT, showed similar optical properties. The RIs of unfilled resins appeared to be good predictors of the RIs of cured RBCs. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 7-13, 2017

Potential environmental application of microbial polysaccharides

Here we report toxicity inhibition effect of microbial exopolysaccharides on copper (II) in acute toxicity tests with Artemia salina and Daphnia magna

Factors Controlling the Change of Soil Erosion Intensity in Mountain Watersheds in Serbia

The intensity of soil erosion is the result of a combined action of natural factors and different human activities. This work aims to determine the factors controlling the change of soil erosion. Eleven watersheds from different parts of Serbia were used as the study area. An Erosion Potential Model was applied to estimate the soil erosion status of the watersheds in two periods, 1971 and 2010. The model indicated that the reduction of soil erosion intensity in the watersheds ranges from 12.4% to 82.7%. The statistical analysis examines quantitative relationships and combined effects between soil erosion and socio-economic and main physical-geographical determinants in watersheds. Watershed characteristics were divided into 5 classes, and within each class 22 variables were calculated: two variables relate to erosion, one to topography, two to land cover, seven to demographic and ten to agrarian variables. Correlation analysis and Principal Component Analysis (PCA) have been applied to understand the main variables that contribute to change soil erosion intensity. The PCA identified four components that can explain at least up to 79.06% of the variation of all variables. This study explores new indicators for correlations with changing soil erosion and provides decision makers with access to quantification for environmental impact assessment and decision-making for adequate soil conservation and management programs

Potential environmental application of microbial polysaccharides

Here we report toxicity inhibition effect of microbial exopolysaccharides on copper (II) in acute toxicity tests with Artemia salina and Daphnia magna

Factors Controlling the Change of Soil Erosion Intensity in Mountain Watersheds in Serbia

The intensity of soil erosion is the result of a combined action of natural factors and different human activities. This work aims to determine the factors controlling the change of soil erosion. Eleven watersheds from different parts of Serbia were used as the study area. An Erosion Potential Model was applied to estimate the soil erosion status of the watersheds in two periods, 1971 and 2010. The model indicated that the reduction of soil erosion intensity in the watersheds ranges from 12.4% to 82.7%. The statistical analysis examines quantitative relationships and combined effects between soil erosion and socio-economic and main physical-geographical determinants in watersheds. Watershed characteristics were divided into 5 classes, and within each class 22 variables were calculated: two variables relate to erosion, one to topography, two to land cover, seven to demographic and ten to agrarian variables. Correlation analysis and Principal Component Analysis (PCA) have been applied to understand the main variables that contribute to change soil erosion intensity. The PCA identified four components that can explain at least up to 79.06% of the variation of all variables. This study explores new indicators for correlations with changing soil erosion and provides decision makers with access to quantification for environmental impact assessment and decision-making for adequate soil conservation and management programs

Can Depopulation Stop Deforestation? The Impact of Demographic Movement on Forest Cover Changes in the Settlements of the South Banat District (Serbia)

The key problem of rural settlements in the South Banat district lasted into the 21st century through the spread of depopulated areas. Considering that settlements give a cultural landscape its basic features, that they are the main bearers of functional organization, and the hotspots of geo-spatial transformation, based on quantitative-qualitative indicators this paper analyzes the spatial-demographic determinants of the development of 94 settlements, and the impact of depopulation on the changes in the surrounding forest cover. The time span included in the analytical-statistical research of the demographic components and forest dislocation lasted from 1990 to 2018. Geo-spatial data for forest areas were taken from the Corine Land Cover database. The data obtained were then turned into visual representations, or maps, using the GIS ArcMap 10.8. software. The results indicated that total depopulation has been an ongoing, 30-years process in this area on the one hand, while the forest cover in the depopulated settlements located on the outskirts of the Deliblato sands (a special nature reserve) has decreased, and the forest cover in the depopulated settlements in the zone of the Vršac mountains has increased, on the other. These analyses are useful for obtaining more detailed insight into the state of forested areas in this part of Serbia, which is the least afforested one