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Introduction In addition to good biological properties, biomaterials should also possess appropriate physical properties in order to provide stability and longevity at the place of application. The aim of this work was to evaluate physical properties of an experimental nanostructured material based on calcium aluminate (CAL) and calcium silicate (CS). Material and method The research used nanostructured calcium aluminate synthesized by the hydrothermal solgel method from the individual components of calcium aluminate (CaO·Al2 O3 ), calcite (CaCO3 ) and barium sulfate (BaSO4 ) as an X-ray contrast agent and calcium silicate (CS). The prepared material was placed in plastic molds with a diameter of 5 ± 0.1 mm and a height of 2 ± 0.1 mm. After setting time, the materials were left in an incubator at 37°C for 24 hours, and then they were removed from the mold and absorption and solubility of the materials was calculated. MTA (Angelus Londrina, Brazil) was used as a control material. Results The lowest material solubility was recorded with MTA (0.255 mg/mm3 ), followed by calcium silicate (0.267 mg/mm3 ), and the highest with calcium aluminate (0.725 mg/mm3 ). The difference was statistically significant between calcium aluminate and MTA (p = 0.001901) and between calcium aluminate and calcium silicate (p = 0.002550). After 28 days in deionized water, the lowest water sorption was recorded with MTA (0.347 mg/mm3 ), followed by calcium silicate (0.357 mg/mm3 ), and the highest water sorption was measured with calcium aluminate (0.474 mg/mm3 ). Statistically significant differences were observed between calcium aluminate and MTA (p = 0.000283) and between calcium aluminate and calcium silicate (p = 0.001576). Conclusion Material solubility and water absorption of calcium aluminate-based nanostructured material was significantly higher compared to calcium silicate (CS) and MTA.

Introduction Marginal seal or adequate marginal adaptation of material along the cavity walls should be able to prevent leakage of tissue fluid and consequently bacterial microleakage, terefore, it is considered as significant factor for long term success of endodontic treatment. The aim of this work was to test the marginal microleakage of newly synthesized nanostructured biomaterials based on calcium aluminate, calcium silicate and MTA with a dye penetration test after application the material to the interradicular perforations of extracted teeth. Material and method The study included 48 extracted human maxillary and mandibular molars. Newly synthesized nanostructured materials were tested: material based on calcium aluminate, calcium silicate. Commercial calcium silicate cement (MTA Angelus, Londrina, Brazil) was used as a control material. Marginal microleakage was examined with a dye penetration test six months after application of the material in experimentally prepared interradicular perforations on extracted human molars. Penetration depth measurement was analyzed with a binocular magnifier (Leica DM 500, Leica Byosistems). Results are expressed in millimeters and statistically processed by applying the analysis of variance for repeated measurements with the Sidak test. Results The lowest average penetration (mm) was for MTA (1.40 ± 0.63 mm), and the highest for Ca aluminates (2.10 ± 0.63 mm), while for calcium silicates an average color penetration of 1.73 ± 0, 67mm was recorded. By testing intergroup differences in color penetration between groups, a statistically significant difference between MTA and Ca aluminate was obtained using Sidak's test (t = -0.693; p = 0.036). No statistically significant difference was recorded between MTA and Ca silicate, nor was there a statistically significant difference between Ca aluminate and Ca silicate. Conclusion The lowest marginal microleakage, the best marginal sealing, was recorded with the MTA material. The microleakage of calcium aluminate-based materials was significantly higher compared to calcium silicate and MTA.

Numerous technological solutions in recent years have significantly improved the cleaning and shaping of canals and made canal instrumentation simpler, more efficient and safer. Significantly faster and less stressful canal instrumentation for the therapist is enabled by the specific design of the file working part and a special thermal modification of NiTi alloy with a change in the movement dynamics of the file in the canal. Research has shown that the problem of cyclic fatigue and torsional stress of the file during canal preparation can be solved by changing usual continuous rotation of the file. Dental technology has introduced the technique of reciprocal movements as an alternative to full file rotation. This change in file rotation direction during instrumentation, based on the technique of balanced forces, significantly reduces contact surface with the canal wall, eliminates the effect of screwing, extends the life of the file and further increases safety of instrumentation of different canal systems. An important advantage of changing the usual dynamics of file movements is that the concept of reciprocal movements is based on the use of only one file, which in addition to shortening treatment time also makes this intervention safer and with significantly lower percentage of defects and fractures of NiTi files. The aim of this paper was to present the concept of canal instrumentation with NiTi files with reciprocal movements as well as development, properties and possibility of application of these files in different clinical situations.

Introduction ALBO-HA (Vinca, Serbia) is new nanostructured calcium aluminate cement, synthesized as a potential alternative to mineral trioxide aggregate (MTA). The purpose of this study was to compare the periapical tissue response to new nanostructured calcium aluminate cement ALBO-HA with white MTA (MTA Angelus, Londrina, Brasil) as root-filling material into the root canal of sheep' s teeth. Material and methods Sixteen mandibular incisors from two 24-month-old sheep were used. Root canals were pre pared and filled with ALBO-HA (group 1) or MTA (group 2) (eight teeth per group in each sheep). After four weeks the animals were sacrificed, teeth with surrounding tissue removed, and histologically processed. The sections were analyzed for determination of scores of the following parameters: periapical inflammatory infiltrate, newly mineralized apically formed tissue, apical periodontal ligament space thickness and resorption of dentin, cementum and bone. Data were analyzed statistically (a=0.05) using Mann-Whitney U test. Results Slight inflammatory infiltrate was observed in 75.0% and 62.5% of samples in the group 1 and group 2, respectively (p>0.05). Partial newly mineralized apically formed tissue was found in 75.0% of samples in the group 1, and 87.5% of samples in group 2 (p>0.05). No significant difference was noted for periodontal ligament space thickness (p>0.05). Resorption of dentin, cementum or bone was not observed. Conclusion ALBO-HA and white MTA Angelus had a similar effect on inflammation, newly mineralized apical tissue formation and thickness of periodontal ligament space after root canal filling under the present experimental conditions.

More certain therapeutic and significantly facilitated solution of everyday endodontic problems are provided by the introduction of NiTi rotary files in endodontic practice and their proper application. However, their widespread use has caused more and more frequent fractures and has become a significant frustrating factor that diminishes their numerous benefits. Torsional stress and cyclic fatigue are the main reasons for the occurrence of a fracture, and the frequency of NiTi file fractures is exactly proportional to the degree of bending of the canal, knowledge of the features of the file, ie. the skill and expertise of the therapist. The most dominant factor for the occurrence of fractures is the dentist who, in addition to manual dexterity, must have a good knowledge of the anatomy of various canal systems and file design in order to make the best choice for each individual case. Properly formed access cavity and knowledge of the working part of NiTi files enable maximum realization of endodontic skills, increased efficiency of intervention and reduced possibility of error during canal instrumentation. The special treatment of NiTi alloy and new solutions related to the design of the working part have significantly increased file flexibility and resistance to cyclic fatigue. Specific design (reduced number of threads, change of conicity, interruption of blade continuity), reduced engagement of file, ie. change of dynamics of movement in the canal (full rotation, reciprocal, eccentric, transaxial), as well as reduced number of processing files, have also significantly influenced the reduction of fracture risks. The aim of this paper was to analyze the most common reasons for the fracture of NiTi files and emphasize measures and factors that can increase their safe use and reduce complications during canal instrumentation.

Introduction This review aims to investigate modern methods of applying artificial intelligence to diagnose SARS Cov-2 and predict the development of potential emergencies. Methods The most commonly used electronic databases, such as Scopus and Medline during 2020, were searched. A narrative approach was used to synthesize the extracted data. Results In this review paper, it has been shown that the application of artificial intelligence plays a significant role in virus diagnosis and prognosis in clinical trials. It allows resources to be used much more rationally, such as respirators , in hospitals, during the treatment of SARS Cov-2 and the prediction of possible mortality. The obtained results are from the analysis performed on 120 papers and studies that were electronically taken from papers published on Scopus and Pub Med line. Most commonly used artificial intelligence techniques are convolutional neural networks and machine learning. Conclusions Included studies showed that artificial intelligence can significantly improve the treatment of SARS Cov-2, although many of the proposed methods have not yet been clinically accepted. In addition, more effort is needed to develop standardized reporting protocols or guidelines on applying artificial intelligence into conventional clinical practice. This technology is suitable for fast and accurate diagnosis, prediction and monitoring of current patients and prognosis of disease development in future patients.

In this paper viruses are considered as very efficient nano-machines that produce numerous copies of them. Observing these nano-architectures, the question arises: which molecular forces and processes make up the set of such structures, given that they are extremely inspiring for development of new technologies at the nano level. There is a need for deep understanding of individual molecular building blocks and their structures, properties of their assemblies and dynamic behavior.

Introduction The aim of this study was to analyze working surfaces of new hand endodontic instruments and to check possible existence of dirt or defects on working surface that resulted from manufacturing process using SEM. Material and methods Three sets of new hand instruments: K-File (KF), (18 instruments) (Dentsply Maillefer, Switzerland) and Hedstorm Files (HF), (18 instruments) (SybronEndo Co, USA) were used. Instruments were analyzed by SEM method at 170× magnification while semi-quantitative EDS analysis was used to determine chemical composition of dirt particles. Fisher test (p < 0.05) was applied in statistical analysis. Results Results showed that none of the instruments was defect-free. The most common defects were metal strips and fretting noticed at the surface of all tested instruments. Debris was present on all KF (100% in apical and middle third) and HF (56% in apical and 56% in middle third) instruments. Pitting was noticed in KF (33% in apical and 39% in middle third) and HF (11% in apical and 6% in middle third) instruments. Corrosion of working surface, metal flash and disruption of cutting edge were marked only in KF group. Conclusion Manufacturing defects were noticed in all instruments and the most common type of irregularity were metal strips and fretting.

Introduction Materials used for root canal obturation and root perforation are expected to have, in addition to preventing apical, lateral and coronary leakage, antimicrobial effects on microorganisms that are not accessible to chemomechanical instrumentation and intra-canal medications. The aim of this study was to evaluate the antimicrobial effect of a novel calcium aluminate-based endodontic nanostructured biomaterial (ALBO-MCCA) using agar diffusion test. Material and methods the two materials were tested in the study. The nanostructured calcium aluminate was synthesized by the hydrothermal sol-gel method from individual components of calcium aluminate (CaOxAl2 O3 ), calcite (CaCO3 ) and barium sulfate (BaSO4 ) as radiocontrast agent in the ratio of 2:2:1 according to V. Jokanovic's recipe. The other used material was calcium silicate MTA Angelus (Londrina, Brazil). The antimicrobial effect was assessed using agar diffusion test. Standard strains of Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, cultured on blood Mueller-Hinton agar and Candida albicans cultivated on Sabouraud Dextrose Agar, were used as test microorganisms. Results the best antimicrobial effect after 24 h both materials showed against S. aureus. The mean values of the growth inhibition zone for ALBO MCCA were 5.7 ± 0.25 mm and MTA 6.2 ± 0.4 mm. The ALBO MCCA material showed slightly stronger antibacterial effect against E. coli compared to MTA (p < 0.05), whereas none of the materials showed antibacterial effect against E. faecalis. Conclusion the ALBO MCCA material showed certain antibacterial effect on Escherichia coli, Staphylococcus aureus and Candida albicans that was comparable to antibacterial effect of MTA.

Various magnetron-sputtering methods for surface modification of shape memory alloys (SMA) are described in this paper. These methods belong to the most effective methods, which enable mechanical reinforcing of the SMA, showing numerous advantages over conventional methods of electro-polishing. In addition, surface modified SMA, particularly with equiatomic TiNi coatings, is crucial for further development of various endodontic instruments; wires and brackets used for orthodontic teeth movements. Active coatings with bactericide properties and coatings that can be used as barrier for release of toxic Ni ions from the bulk body of SMA obtained by various magnetron-sputtering methods can be successfully combined. Therefore, the review of these methods is given in this paper, with their main characteristics and drawbacks. Magnetron sputtering deposition involves surface modification of SMA in a single-layer, multilayer, graded layers, and nanocomposite thin coatings for obtaining systems with superior "functional" characteristics. These are hardness, scratch, abrasion, and erosion resistance, improved adhesion to various technologically important substrate materials such as polymers, hydrophobicity or hydrophilicity, long-term chemical, thermal, and environmental stability, gas and vapor impermeability, and others. This paper is critical review of the advances in the development of magnetron sputtering modified SMA products in dentistry, with in advance predictable physicochemical, structural and antimicrobial properties.

Introduction The aim of this study was to compare compressive strength (Cs) of new nanostructural calcium silicate based cement (nCS) with commercial calcium silicate cement and conventional GIC. Methods Four nanostructural materials were tested: nanostructural calcium silicate based cement (nCS) (Jokanović et al.), MTA Plus (Cerkamed, Poland), Fuji IX (GC Corporation, Japan) and Ketac Universal Aplicap (3M ESPE, USA). Five samples of each material were mixed in accordance with manifecturer's guidelines and positioned in metal moulds (ϕ4mm and 6mm). Compressive strength (Cs) expressed in MPa was determined after 24 hours, 7 days and 28 days respectively. Measurements were performed on universal testing equipment (Tinius Olsen, USA) at a crosshead speed of 1mm/min. For processing the results one-way ANOVA and post-hoc test were used. Results The highest values of compressive strength after 24h was found in conventional GIC Fuji IX (mean 38.56±13.31) and Ketac Universal (mean 40.77±7.96). Calcium silicate cements after 24h showed low values of compressive strength (MTA Plus 5.91±0.28 MPa, nCS 1.35±0.36 MPa). After 7 days, FUJI IX 47.42±9.33 MPa and Ketac Universal 35.25±10.60 MPa showed higher value of compressive strength than MTA Plus (15.09±2.77 MPa) and nCS (11.06±0.88 MPa). After 28 days the Cs value for conventional GIC Fuji IX was 48.03±7.82 MPa and Ketac Universal 36.65±11.13 MPa while for calcium silicate cements it was 16.47±1.89 MPa and nCS 14.39±1.63 MPa. There was statistically significant difference (p

Introduction Cytokine network plays an important role in pathogenesis of chronic periapical lesions. The aim of this study was to determine the concentration of interleukin-6 (IL-6) in tissue homogenates of human periapical lesions and correlate its levels with symptomatology and size of the lesions. Materials and Methods 93 samples of chronic periapical lesions were obtained after extraction of teeth. Samples were divided according to the clinical presentation as symptomatic and asymptomatic, and according to the size as large and small. The concentration of IL-6 was analyzed using ELISA. Results Statistically significant difference in IL-6 concentration was observed in symptomatic lesions compared to asymptomatic (p

Introduction Efficient cleaning and canal design present a basic precondition for successful endodontic treatment. The aim of this study was to evaluate, using SEM analysis, the efficacy of cleaning the apical third of the canal with one instrument in both reciprocating motion and full rotation systems. Materials and methods Thirty (30) single-rooted teeth (upper incisors), extracted due to periodontal problems, were used and selected in 2 groups. In the group 1, instrumentation was done with a single instrument UNICONE with reciprocal movements (MEDIN, Czech Republic), while in the group 2, a single instrument XPS endo SHAPER (XPS) (FKG, Dentaire, Swiss) with full rotation was used. 2% solution of NaOCl and 17% EDTA solution were used as irrigation agents in both groups. SEM analysis of the smear layer in the apical third was done at standard magnification of 1000x and presented on a scale of 1-5. Results showed mostly clean canal walls and no smear layer in the apical region in both tested groups. Canal walls were somewhat cleaner after using UNICONE with reciprocal movements (80%) compared to the canals instrumented with XPS ENDO SHAPER (76%), but this difference was not statistically significant. Conclusion Single-file NiTi systems did not remove smear layer completely, but provided efficient cleaning in the api-cal part of the canal. UNICONE file with reciprocal movements was somewhat more efficient in removing the smear layer compared to the full rotation XPS ENDO SHAPER file.

Introduction the main objective of endodontic treatment is to eliminate infection from root canal and prevent re-infection by three-dimensional hermetic obturation of the canal system. Endodontic failure can occur due to inability of complete control and elimination of infection from the root canal. The aim of this study is to investigate, by PCR technique, microbiological status of previously endodontically unsuccessfully treated teeth immediately after the removal of obturation material. Material and Methods the analysis included 30 teeth indicated for endodontic retreatment. After removing previous root canal filling material, the bacteriological sample was taken by sterile instrument (# 15) and paper points. Standard PCR technique was used to analyze the incidence of E.faecalis, P.micros, P.intermedia, P. endodontalis and a.actinomycetemcomitans. Results Positive bacteriological findings were registered in 80% of cases, while bacteria were not identified in 20% of all samples (all taken from the root canals without significant changes in periapical tissue). From 24 canals with identified bacteria, 17 had affected apical periodontium. The most dominant microbe in root canals with positive bacteriological finding was E.faecalis (83.3% of the canals) and P.intermedia (75%). In case of teeth with chronic periapical changes, the most common was E. faecalis (94%) and P.intermedia (82.3%). Conclusion the presence of periapical lesions significantly affects microbiological status of endodontically treated teeth. The presence of bacteria was confirmed in most teeth with periapical lesions, while the most frequently identified bacteria were E. faecalis, P.intermedia and P.micros.

Background: 3D modelling in orthodontics is becoming an increasingly widespread technique in practice. One of the significant questions already being asked is related to determining the precision of the scanner used for generating surfaces on a 3D model of the jaw.

There is growing need for synthetic tissue replacement materials designed in a way that mimic complex structure of tissues and organs. Among various methods for fabrication of implants (scaffolds), 3D printing is very powerful technique because it enables creation of scaffolds with complex internal structures and high resolution, based on medical data sets. This method allows fabrication of scaffolds with desired macro- and micro-porosity and fully inter- connected pore network. Rapid development of 3D printing technologies has enabled various applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. The aim of current investigations was to develop compatible printers and materials (bioinks) to obtain biomimetic scaffolds, which allow printing of living cells without significant loss of cell viability. The advanced level of such printing assumes “in situ” printing, i.e. printing cells and biomaterials directly onto or in a patient that will reduce recovery time.

Introduction Development of inflammatory lesions or their persistence after primary treatment is considered endodontic failure. The reason for failure can be complex anatomy of the canal system and numerous iatrogenic factors. The objective of this study was to analyze, clinically and radiographically, the causes of primary endodontic treatment failure and assess possibilities for retreatment of teeth with failed endodontic treatment. Method The study included 79 teeth (36 multirooted and 43 singlerooted tooth) indicated for repeated endodontic treatment. Based on the radiographic assessment of the status of periapical structures, teeth were divided into two groups. The first group included teeth without periapical lesions, i.e. the healthy periodontal tissues (PAI score of 1 and 2) in which retreatment was required for prosthodontic reason due to the poor quality of obturation (28 teeth), and the second group included teeth with visible signs of periapical tissue damage (PAI scores 3, 4 and 5) (51 teeth). In both groups, quality of obturation, coronal sealing and the presence or absence of clinical symptoms was analyzed. Results The most common radiographic finding of definitive obturation was short filling (65.8% of cases); “forgotten” canals (25.3%); non-homogeneous obturation with correct length (5.1%) and fractured instrument (3.8%). There was significant difference between healthy periodontal ligament and adequate restoration (P < 0.001). In 95% of patients with symptoms, changes in the periapical tissue were observed. Also, there was significant difference in the presence of symptoms after primary treatments, between the teeth with healthy apical periodontal tissue and teeth with periapical lesions (P = 0.019). Conclusion The outcome of the root canal treatment is significantly affected by the quality (density) of obturation and the presence and quality of coronal restoration. In patients with symptoms there were changes in the periapical tissue.

Introduction The aim of this study was to evaluate the efficacy of new rotary NiTi instrument XP endo SHAPER (XPS) used with conventional irrigation protocol on the root canal cleaning in the apical area. Material and methods The research was conducted in vitro on 40 extracted single-rooted teeth divided into the four groups. Instrumentation in the first group was performed using iRa Ce NiTi rotary instruments, in the second group the same instruments were used plus XP endo FINISHER (XPF) for smear layer removal. In the third group, canal instrumentation was done using new instrument XPS, and in the fourth XPS instruments plus XPF was used. During the instrumentation 2% NaOCl solution was used for rinsing canals. The SEM analysis of the cleaning quality in the apical third of the canal was performed on longitudinal root cross-sections and standardized microphotography with a 2000x magnification. Results The thickest smear layer in the apical third was recorded in the first group (iRa Ce) NiTi instruments (2.12), and somewhat less in the group with the new XPS instrument (1.95). An identical and somewhat smaller amount of smear layer was registered in the second and fourth groups where XPF was used with the final irrigant (1.64) (p

This paper analyzes mechanisms of fluorapatite mechanochemical synthesis and its structural characteristics. Several studies of Jokanovic et al. published in appropriate journals and the book 'Nanomedicine, the biggest challenge of the 21st century' are the base for this article. Characteristics of obtained materials show numerous biological advantages associated with the specific structural design of material during the process of synthesis. X-ray diffraction (XRD) and infrared spectroscopy with Fourier transform (FTIR) were used for studying the processes of fluorapatite synthesis.

Introduction Direct pulp capping is an important therapeutic method that has goal to provide formation of dentin bridge and healing process of the pulp. The aim of this study was to investigate the effects of new nanostructural materials based on calcium silicate systems and hydroxyapatite on exposed dental pulp in Vietnamese pigs. Material and Methods The study was conducted on 30 teeth of two Vietnamese pigs (Sus scrofa verus). On buccal surfaces of incisors, canines and first premolars, class V cavities were prepared with a small round bur and pulp horn was exposed. In the first experimental group (10 teeth) the perforation was covered with new nanostructural material based on calcium silicate systems (CS). In the second experimental group, the perforation was covered with compound of calcium silicate systems and hydroxyapatite (HA-CS) (10 teeth). In the control group, exposed pulp was covered with Pro Root MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA) (10 teeth). All cavities were restored with glass ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). Observation period was 28 days. After sacrificing the animals, histological preparations were done to analyze the presence of dentin bridge, inflammatory reaction of the pulp, pulp tissue reorganization and the presence of bacteria. Results Dentin bridge was observed in all teeth (experimental and control groups). Inflammation of the pulp was mild to moderate in all groups. Neoangiogenesis and many odontoblast like cells responsible for dentin bridge formation were detected. Necrosis was not observed in any case, neither the presence of Gram-positive bacteria in the pulp. Conclusion Histological analysis indicated favorable therapeutic effects of new nanostructural materials based on calcium silicate systems and hydroxyapatite for direct pulp capping in teeth of Vietnamese pigs.

Introduction During endodontic treatment smaller or larger areas of root canal wall remain non-instrumented. This can affect prognosis of endodontic treatment as some bacteria may be left behind. The purpose of this study was to evaluate the morphology of non-instrumented areas of the root canal wall using scanning-electron-microscopy (SEM) after completed instrumentation and various irrigation regiments. Materials and Methods Eighteen single-rooted extracted teeth were divided into the six groups. One tooth in each group represented a control sample. In all samples only one half of the canal was instrumented using ISO 40 hand files. Control samples were subjected to an irrigation protocols without instrumentation. Irrigants used were physiological saline, 3% sodium hypochlorite and 15% of ethylene-diamine-tetra-acetate. Irrigation protocol included using each of these irrigants alone, or a combination of NaOCl and EDTA, as well as their combination with final irrigation using NaOCl or chlorhexidine. Then after, roots were sectioned longitudinally and prepared for SEM. Results Saline irrigation left pulpal debris on uninstrumented areas of the canal wall. Irrigation with 3% NaOCl left behind canal wall with different forms of calcospherites. However, after EDTA irrigation dentin appeared as an undulating surface with open tubules without a smear layer. The combination of NaOCl and EDTA showed remnants of calcospherites and open slightly widened dentinal tubules. Final irrigation with NaOCl on the uninstrumented areas showed enlarged dentinal tubules along with dentinal erosion, while after final irrigation with CHX clean dentin and open dentinal tubules without smear layer were noted. Conclusion From the morphological point of view, the most favorable effect of irrigation on both uninstrumented and uninstrumented canal walls was achieved after irrigation with NaOCl and EDTA or NaOCl, EDTA and chlorhexidine as the final irrigant.

Bioactive glasses are often used nanomaterials in tissue engineering of bone and soft tissue. Many newly synthesized materials for applications in medicine and dentistry are based on these bioactive substances. Bioactive glass is usually used as a scaffold or as an implant coating on implants and it allows fast formation of apatite layer with positive effect on osteoblasts proliferation. These biomaterials play an important role in dentistry and endodontics. This study is mostly part of the monograph titled 'Nanomedicine, the Greatest Challenge of the 21st Century', that for two years has received attention from professional and scientific community in various fields. Information presented in this paper highlight structural characteristics of bioactive glasses that have a significant role in bone tissue engineering.

Introduction Calcium silicate cements can be successfully used for the treatment of root perforations due to their exceptional biological and sealing properties. The aim of this study was to test, using dye penetration method, marginal microleakage of newly synthesized nanostructured biomaterials based on calcium silicate system and hydroxyapatite after their application in interradicular perforation of extracted teeth. Material and Methods The study included 34 extracted human molars. Newly synthesized nanostructured materials: one based on calcium silicate system (CS), and the other one based on hydroxyapatite and active calcium silicate system (HA-CS) were tested. Mineral trioxide agreaggate (MTA; Angelus, Londrina, Brazil) was used as control. Marginal microleakage was evaluated using dye penetration test 6 months after the application of materials in experimentally prepared inter-radicular perforations in extracted human molars. Dye penetration was analyzed using light microscope at 30X magnification, a method of quantifying visual information in computer software for image processing (Adobe Photoshop CS5 Extended, version 12.0 x 32). The values were expressed in millimeters, and the results statistically analyzed using one-way ANOVA and Tukey post-hoc test (α=0.05). Results The shortest dye penetration was measured for calcium silicate system (0.44 mm), while slightly higher values were found for MTA (0.54 mm). Dye penetration for hydroxyapatite and active calcium silicate system (2.00 mm) was longer than for the other two materials (p

Introduction The aim of this study was to evaluate using SEM analysis the effectiveness of a new instrument XP-endo Finisher in cleaning root canal walls after instrumentation with BioRaCe NiTi rotary instruments. Material and Methods This in vitro study was conducted on 30 extracted single rooted teeth divided in two groups. Instrumentation of all canals was done using basic BioRaCe NiTi rotary instruments with copious irrigation of 2% NaOCl. In the first group, after complete instrumentation smear layer was removed using XP-endo Finisher, while the other group served as negative control. The roots were then after longitudinally cut and SEM analysis was performed. The presence of smear layer in the coronal, middle and apical third was assessed. The data were statistically analyzed using Mann-Whitney U-test (p

Introduction Separation (fracture) of endodontic instruments in the root canal during chemomechanical instrumentation is a complication that can compromise the final outcome of endodontic treatment. One of the most common factors that cause fatigue of endodontic instruments and consequent fracture is surface corrosion. The aim of this study was to investigate the ultrastructure of surface corrosion of endodontic instruments made of stainless steel and nickel-titanium after immersion in the most commonly used root canal irrigants. Material and Methods The study included 48 nickel-titanium and stainless steel endodontic hand files. All instruments were immersed in 5.25% sodium hypochlorite, 0.2% CHX and 17% EDTA. Surface corrosion was analyzed using a scanning electron microscope (SEM). Results Nickel-titanium instruments showed significantly higher susceptibility to corrosion after immersion in 5.25% sodium hypochlorite compared to stainless steel instruments (p

Introduction. The balance between proinflammatory and anti-inflammatory cytokines plays an important role in the pathogenesis of chronic periapical lesions. The aim of this study was to determine the concentration of TNF-α in tissue homogenates of periapical lesions and analyze its levels in relation to the symptomatology and the size of lesions. Materials and Methods. 93 samples of chronic periapical lesions were obtained after extraction of teeth. Samples were classified according to the clinical presentation as symptomatic and asymptomatic, and according to the size as large and small. The concentration of TNF-α was analyzed using ELISA. Results. The results showed increased production of TNF-α in symptomatic lesions compared to asymptomatic. Higher concentration of TNF-α was demonstrated in large lesions compared to small. Large symptomatic lesions showed greater concentration of TNF-α compared to small symptomatic lesions, while bigger asymptomatic lesions demonstrated higher amount of the cytokines compared to small asymptomatic lesions. Conclusion. Higher concentration of TNF-α in large symptomatic lesions indicates that TNF-α is an important factor responsible for the progression of lesions.

Introduction. Calcium silicate cements are most commonly used materials in endodontics for many indications due to their exceptional biological and physical properties. The aim of this study was to assess solubility and porosity of new experimental nanostructured calcium silicate cement. Material and Methods. A novel nanostructured calcium silicate cement (CS), commercialized calcium silicate cement (Biodentin), traditional glass ionomer cement (GIC) (Micron Superior) and resin-reinforced glass ionomer cement (Fuji VIII) were used in this study. All materials were prepared as per manufactuers’ instructions, placed in metal rings of 16Ч2 mm diameter and kept in an incubator at 37°C for 24 hours. After that they were weighed and put in plastic containers filled with 25 ml of water for additional 24 hours. Then after all samples were weighed again and resorption and solubility were calculated. Results. The highest solubility was found for new CS cement (12.45) followed by conventional GIC Micron Superior (11.5) and Biodentin (6.1) whereas the lowest solubility was for resin reinforced GIC Fuji VIII (3.8). These differences were statistically significant (p

Introduction. The backbone of Serbian health system forms the public healthcare provider network with 355 institutions and around 112,000 employees, owned and controlled by the Ministry of Health and financed mainly by the Republican Health Insurance Fund. The law recognizes private practice that was not included, till recently, in the public funding scheme. New Health Insurance Law (2005) decreased the number of entitlements in the basic health service package. It abolished the right to dental health care for adults (exceptions are: children, older than 65, pregnant women and emergency cases) as well as the right to compensate travel expenses. The aim of this study was to evaluate the effects of health care system of the Republic of Serbia and indicate parameters that determine the state of health of the population, on the ground of data obtained by the Institute of Public Health of Serbia. Results. In the period 2004-2012, cardiovascular diseases represented the main cause of illness in Serbia (50%). In 2012 digestive system diseases were on the second place. Neoplasm and nervous system diseases were on the third place. From 2007 to 2012 there was slight decline in the birth rate and number of deaths, but the death rate increased from 13.9 to 14.2. Health care system in Serbia is funded through the combination of public finances and private contributions. Primary care is provided in 158 health care centres and health care stations, secondary and tertiary care services are offered in general hospitals, specialized hospitals, clinics, clinico-hospital centers and clinical centres. Conclusion. A significant but not satisfactory progress has been achieved in the field of health status indicators as the most important outcome of the final performance of the health system. The transition of public health care system in Serbia since the communist period to present and slow integration with European Union is unfinished process.

Calcium phosphates, together with polymers, are most commonly used materials in bone engineering since their composition is similar to bone. They are used to fulfill various defects caused by injury or bone disease, as well as for the preparation of endodontic mixtures. Because of their great importance in dentistry, these materials are given special attention in the current paper. This paper is a part of the monograph entitled “Nanomedicine, the Greatest Challenge of the 21st Century”, which attracted great interest of technical and professional communities in different areas of medicine. Also for the last two years this book is promoted by the Student Cultural Centre as the only national book chosen in the narrowest election. That fact is very important for young researchers who study tissue engineering, endodontics and implantology.

Introduction. Although many studies have reported various advantages of nickel-titanium endodontic instruments, the use of stainless steel endodontic files still presents a standard in everyday practice. The aim of this study was to evaluate ultrastructure of the surface of stainless steel endodontic instruments before and after their use. Material and Methods. Fourteen sets of non-used stainless steel endodontic reamers and files were included in the study. Each set of instruments was used one, three or six times in simulated clinical conditions on extracted maxillary premolars. After their use the instruments were subjected to cleaning and sterilization procedures. Ultrastructure of the surface of instruments was observed under scanning electron microscope (SEM). Surface analysis was performed based on the number of uses and size of instruments. The following characteristics were analyzed: defects of instrument flutes, defects of cutting edges and instrument deformations. Results. SEM analysis showed defects on the surface of non-used instruments as a result of the manufacturing process. Surface defects, defects of cutting edges as well as flutes deformations were observed after a single use and were more often noticed in small sized instruments. After three uses, flutes deformations were observed in all small sized instruments and some of the medium size. After six uses all groups of instruments showed defects of cutting edges. Conclusion. Non-used stainless steel endodontic instruments showed surface defects created by the manufacturing process. Defects of cutting edges and flutes can be observed after a single use. To minimize complications and mistakes during clinical preparation it is recommended to limit the number of instrument uses.

Introduction. Direct pulp capping is therapeutic method of applying medication on exposed pulp in order to allow bridge formation and healing process. The aim of this study was to investigate the effect of Biodentine on exposed dental pulp of Vietnamese pigs. Material and Methods. The study was conducted on 20 teeth of Vietnamese pigs (Sus scrofa domesticus). On buccal surfaces of incisors, canines and first premolars, class V cavities were prepared and pulp was exposed. In the experimental group (six incisors, two canines and two premolars) the perforation was covered with Biodentine® (Septodont, Saint-Maur-des-Fosses, France). In the control group, the perforation was covered with MTA® (Dentsply Tulsa Dental, Johnson City, TN, USA). All cavities were restored with glass ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). Observation period was 28 days. After sacrificing the animals, histological preparations were done to analyze the presence of dentin bridge, an inflammatory reaction of the pulp, pulp tissue reorganization and the presence of bacteria. Results. Dentin bridge was observed in all teeth (experimental and control groups). Inflammation of the pulp was mild to moderate in both groups. Neoangiogenesis and many odontoblast like cells responsible for dentin bridge formation were detected. Necrosis was not observed in any case, neither the presence of Gram-positive bacteria in the pulp. Conclusion. Histological analysis indicated favorable therapeutic effects of Biodentine for direct pulp capping in teeth of Vietnamese pigs. Findings were similar with Biodentine and MTA.

Introduction. Children with hearing impairment do not understand speech without specific instructions and cannot meet daily life requirements. Children with hearing and speech impairment have higher DMFT index and poorer oral hygiene than healthy children of the same age. The aim of this study was to determine oral health status and the prevalence of dental caries in children attending The Center for Education and Rehabilitation of Speech and Hearing in Banjaluka. Material and Methods. The study was conducted as a cross-sectional study and it included 66 children of both genders, age 3 to 18 years, with deciduous, mixed and permanent dentition. General information about the respondents, their socioeconomic status, dental hygiene habits and frequency of dental visits were obtained using a questionnaire. Dental examination was performed using a dental mirror, regular and proximal probe on the daylight, in accordance with World Health Organization guidelines. Oral examination included: number of present teeth, presence of caries, restorations, number of extracted teeth. These data was entered in each patient’s dental record. The DMFT index was used for the assessment of dental status. Results. Results showed that the mean DMFT value in the total sample was 7.79. There was no significant difference in the DMFT index between genders (p=0.19). The significant difference was not found between children who live with parents and those who live in foster families (p=0.15). It was observed that the respondents from rural areas had higher DMFT index (8.68) than respondents from urban areas (5.83). The DMFT index increased with age and school age (p

Introduction. Lack of proper adhesion is one of the most common problems in modern restorative dentistry and the main cause of the occurrence of microcracks at the interface between materials and hard dental tissue. The aim of this study was to assess the quality of bond between two types of glass-ionomer cement (GIC) class V restorations and hard dental tissues by SEM. Materials and Methods. This clinical study included 20 intact teeth (premolars and molars) recently extracted for orthodontic reasons in patients of both genders and different ages. Class V cavity with rounded walls was prepared on vestibular and oral surfaces of all teeth (3x2x2 mm). Conventional GIC Fuji II was applied on vestibular surface of teeth whereas on oral surface resin-reinforced glass ionomer Fuji II LC was placed. The bond between fillings and hard dental tissue was assessed by SEM. Results. Both materials showed microcracks, however, microleakage was lower with Fuji II LC than with Fuji II. Microcracks were observed in 65% of cases (13 restorations) restored with GIC Fuji II and 35% (7 fillings) restored with GIC Fuji II LC. The size of microcracks for Fuji II LC was 9 μm while this value for Fuji II was 17 μm. The difference was statistically significant. Conclusion. Better bond between material and hard dental tissue was achieved with the material of new generation, resin modified GIC.

Introduction. Mineral trioxide aggregate (MTA) is one of the most commonly used materials in endodontics. Given its shortcomings, there is an intensive search for new materials. Calcium-silicate phase (CS phase) is a new material synthesized by the method based on a combination of sol-gel process and self-propagation synthesis which can significantly improve setting time through accelerated hydration. The aim of this study was to explain the mechanisms of hardening of CS phase in aqueous medium as similar mechanism is expected in contact with body fluids. Materials and Methods. CS phases Ca3SiO5 (C3S) and 2β-CaSiO4 (β-C2S) were synthesized from CaCl2•5H2O (Merck, Germany). To investigate the process of hydration, CS were mixed with water and kept at 37 °C for 28 days in closed polyethylene containers. Analysis of the composition of samples before and after immersion in water for 1, 3, 7 and 28 days was performed using X - ray diffractometry and IR. Results. XRD patterns for hydrated samples during 1, 3, 7 and 28 days showed that the amount of hydrated tobermorite phases relative to the amount of CS phase changes with the time of hydration. After 1 day, in addition to the hydrated phases, a significant amount of untransformed β-C2S and C3S were found while after 28 days hydrated CS phase was completely transformed to tobermorite with a small amount of portlandite. Conclusion. Using combined method of sol-gel and self-propagating waves at high temperature very active nanostructured silicate phases were obtained. Hydration process of CS phases was analyzed using XRD and FTIR, the mechanism of hydration was proposed and it was pointed to the difficulties in determining the exact reaction as well as the problem of determining the exact structure of tobermorite. [Projekat Ministarstva nauke Republike Srbije, br. 172026]

This article provides an overview of calcium phosphate systems used in different formulations of cement mixtures. Chemism of reactions that occur in contact of these systems with water medium shows diversity and specificity of each of selected types of mixtures. As it can be clearly seen from reactions that occur between components of cement mixtures, highly active calcium deficient hydroxyapatite is always an end product in all reactions. This makes these systems extremely biocompatible and suitable for use in dentistry from the standpoint of chemical and biological degradability.

Introduction. Dental status in people with special needs is generally non satisfactory. Children with special needs have difficulties in maintaining oral hygiene, they require special conditions for dental care and because of previous negative experience they often show emotional vulnerability. Development of oral and dental diseases in these subjects is the consequence of insufficient knowledge about the causes of these diseases, poor eating habits, low level of oral hygiene and inadequate number of visits to dentist. The aim of this study was to determine dental status and the prevalence of dental caries in children with special needs in the institution “Zaštiti me” in Banjaluka. Material and Methods. The study included 82 children (53 boys and 29 girls) with mixed and permanent dentition age 5-15 years. They were divided into four groups according to their diagnosis. The first group included children with combined disorders of speech development and hearing, in the second group were children who had neurological disorders without mental retardation, third group included children with mild mental retardation and fourth group comprised children with moderate mental retardation. For each patient the number of teeth, the presence of caries and restorations, the number of extracted teeth, the presence of residual roots and the presence and number of fixed restorations were recorded. Results. Mean DMFT of all teeth was 9.77. Detailed analysis showed the greatest number of decayed teeth (83.83%), and filled teeth (9.52%) whereas the least number was for extracted teeth (6.65%). The highest percentage of children (79.27%) did not have any class I composite filling or one amalgam filling class I (82.92%). Only one child had a fixed restoration. Conclusion. The status of teeth in children with special needs in the institution “Zaštiti me” in Banjaluka indicated high percentage of carious teeth, small percentage of restorations and extracted teeth, and inadequate oral hygiene.

Introduction. Health care, as one of the most important and sensitive fields of human endeavour, has a significant social impact; therefore changes in this area have wide implications on society in general. The latest economic crisis resulted in slow growth of gross domestic product (GDP), high unemployment rates, low living standards, and increased poverty across the globe. This includes decreased capacity of health system, and reduced quality and supply of health services. The aim of the study was to explore possible impact of the current world economic crisis on the public health sector workforce in Serbia. Materials and Methods. The study was conducted as retrospective analyses of the Public Health Institute (PHI) human resource data, the Republic Statistical Office publications and database, the Republic Development Bureau report, as well as the analysis of healthcare expenditures obtained from the Chamber of Health Institutions reports. The comparative analytical method was used for the assessment of socio-economic and human resource indicators over the period of five years, 2006 to 2010. Results. Results showed that the world economic crisis discontinued steady economic growth in Serbia. Between 2006 and 2008, the real GDP growth rate has been fluctuating between 3.6% and 5.4 %, while in 2009 it had negative growth rate of -3.1 % and slight increase in 2010 of 1.0%. In 2006, the GDP per capita was US$ 3,943, and by 2008 it almost doubled reaching US$ 6,498, while in 2009 it fell down to US$ 5,499, and continued decrease in 2010 to US$ 5,006. In 2007, the overall inflation rate was 6.5%, and after fluctuaion between 11.7% in 2008 and 8.4% in 2009 it droped again to 6.5% in 2010. According to the PHI, from 2006 to 2008 there was steady increase of full-time employees in the public health care sector; from 108,975 in 2006 to 114,317 in 2008. In 2009, the number of full-time employees slightly declined to 114,175 and 114,432 in 2010. There was constant increase in total number of employees in the public health care sector, from 125,081 in 2006 to 129,357 in 2008. In 2009, the total number of employees decreased to 128,694 and in 2010 to 122,695. At the same time, the total expenditure of human resources in the health sector as the percentage of total health expenditure declined from 37.7% in 2006 to 34.7% in 2010. The public health sector salaries after steady increase from 59.9% of total health expenditure in 2006 to 61.2% in 2007 and 2008, decreased to 56.2% in 2010. The unemployment rate for medical doctors almost doubled in 2010 as compared to 2006. Conclusion. Preliminary study results showed that the world economic crisis had negative impact not only on GDP growth rate, the inflation and unemployment rate, but on the public health sector workforce, their salaries and unemployment rate in Serbia.

Mineral trioxide aggregate (MTA) is a material with broad indications in endodontics. Currently, this material is used for pulp capping, pulpotomy, as apical barrier in teeth with necrotic pulp and open apex, and in the treatment of various root canal perforations. By comparing the biological response of pulp tissue capped with calcium hydroxide and MTA, the superiority of MTA has been indicated. The bridge of hard tissue formed under MTA prevented the irritation of pulp. Histological studies of pulpotomy in dog teeth have shown after 120 days a hard tissue without necrosis formed under MTA. MTA is also the material of choice for retrograde root canal obturation and lateral perforation. Meta analysis of published papers on MTA in recent years indicated the great clinical success of this material which ensured a good canal seal and superior biocompatibility. It is the only material for retrograde root canal obturation that encourages tissue regeneration. Studies have also shown that MTA has inductive and conductive properties for hard tissue as well as the ability to release ions in a liquid medium. The main disadvantage of MTA is related to its color, the presence of iron and mangan ions, the difficulties in maintaining the characteristics of material during time, absence of solvent for this material and the difficulty for its removal after crosslinking.

Introduction. Postoperative pain may develop after chemomechanical preparation during endodontic treatment or retreatment. It is associated with acute apical periodontitis caused by bacteria penetrated from the root canal into the periapical tissue. The purpose of this study was to evaluate the incidence of postoperative pain during endodontic treatment after intracanal medication performed with calcium hydroxide (CH) paste or 1% chlorhexidine gel (CHX). Material and Methods. The study included 22 asymptomatic teeth in both male and female patients. Fourteen teeth had the diagnosis of pulp necrosis and the other eight were retreatment cases. The root canals were prepared by crown-down technique using K files and copious irrigation with 0.5% sodium hypochlorite (NaOCl). Intracanal dressing was performed using either calcium hydroxide paste or 1% CHX gel. Each medicament was placed in the root canals of eleven randomly selected teeth. The teeth were restored with temporary filling. Postoperative pain was registered during the seven day period between two appointments. The level of pain was rated as follows: no pain, mild pain, moderate pain and severe pain (flare-up). The obtained data was analyzed using Fisher exact test. The level of significance was α=0.05. Results. Postoperative pain was absent in 77.3% of total number of treated teeth. Severe pain (flare-up) was registered in 2 cases (9%). There was no significant difference in pain incidence between the CH paste and CHX gel group (p=0.610). Conclusion. Endodontic procedure used in this study which considered root canal instrumentation and irrigation followed by intracanal medication with CH and CHX resulted in low incidence of postoperative pain.

Introduction. As the part of research on costs in the health care system, there is a growing interest in the world for the estimating costs for the treatment of disease. This value represents the burden that a particular disease or group of diseases puts on the society. Until the year 2000, when the Organization for Economic Countries Development (OECD) established a System of Health Accounts (SHA), there was not even approximate methodological guide for calculating the cost of the disease. The aim of this study was to determine the costs of health care in the Republic of Serbia according to the major International Classification of Diseases (ICD-10) and to provide a comparative cost analysis for the treatment of diseases in the period from 2004 to 2009. Material and Methods. A retrospective and comparative analysis of health statistics from the database of the Institute of Public Health of Serbia and financial information provided by the Health Insurance Fund in the period 2004-2009 was performed. Financial information and data on hospital services, outpatient, home health care, ancillary health care services, drug consumption and consumer goods in healthcare were analyzed using SHA methodology. Results. Results showed that during the observation period, the maximum cost of health care in Serbia by main classification of ICD-10 was achieved in 2009 and it was RSD 144,150,456,906.00 (€ 1,503,321,134; $ 2,160,253,219) and the minimal cost was achieved in 2004 - the amount being RSD 49,546,211,470.00 (€ 628,086,723; $ 855,203,134). Results showed that in 2004 the highest costs were allocated to circulatory diseases (18.98%), followed by neoplasm (11.12%), and lowest for congenital anomalies (0.64%). In 2009, the highest costs were allocated to circulatory diseases (18.87%), infectious and parasitic diseases (11.20%), diseases of digestive system (9.26%) nervous system diseases (9.20%), and neoplasm (8.88%), whereas the minimal funds were allocated for congenital anomalies (0.33%). Conclusion. Comparative analysis showed that the value of overall spending in healthcare increased three times in 2009 as compared to 2004.

Introduction. Dental status of most people with special needs is not satisfactory. Many of them are edentulous or toothless, with acute extensive caries lesions present, high DMFT index and severe periodontal disease. The objective of this study was to examine the dental status of mentally impaired persons who live in the special institution “Srce u jabuci” in Pancevo. Material and Methods. Clinical examination was performed on 114 institutionalized patients (68 male and 46 female), age 22 to 71 years. Patients were divided in two groups; the first group consisted of 71 persons who had a moderate mental disorder (F71), while the second group included 43 respondents with severe mental retardation (F72). Oral examination revealed: the number of present teeth, caries lesions, the presence of restorations, the number of extracted teeth, the presence of residual roots, fractures and the presence and number of fixed restorations. Results. The mean DMFT of total examined teeth was 20.33±7.63. The greatest percentage found for extracted teeth (63.76%): in the first group 63.23%, and in the second 64.06%. The percentage of teeth that had caries lesions of all examined teeth was 33.48%, while the lowest percentage was for restored teeth (2.76%). In majority of examined people, initial caries, deep caries, or tooth with the exposed pulp (K1 - 51.74% K2 - 40.35%, K3 - 51.75%) were not found. A high percentage of examined people had more than 10 extracted teeth (52.63%). Most of them did not have any restoration in the mouth (81%) and only three persons had fixed denture. Conclusion. Dental status of institutionalized mentally impaired persons showed high prevalence of extracted teeth, significant presence of carious lesions and small percentage of restored teeth with inadequate oral hygiene.

Introduction. Collecting data about the structure and function of private health care sector in Serbia and its inclusion in joint health care system is one of the most important issues for making decisions in health care and getting more accurate picture about the possibilities of health care system in Serbia. The aim of this analysis was to compare health institutions, personnel, visits, number of hospital days and morbidity by ICD-10 classification of diseases in public and private health sector in South Backa, Nisava, Toplica and Belgrade district in 2009. Material and Methods. A retrospective comparative analysis was performed using data about private providers of health services obtained from the Institute of Public Health Novi Sad, the Institute of Public Health Nis and the City Institute of Public Health Belgrade. Data about personnel and morbidity in public health sector in Serbia for 2009 was obtained from the Center for Information Technology of the Institute for Public Health of Serbia. Data about public health facilities in South Backa, Nisava, Toplica and Belgrade district in 2009 was obtained from Serbian Chamber of medical institutions. Results. The results showed that health care was provided in Belgrade district in 2009 by total of 1,051 employees in private sector and 31,404 in public sector. We found that public sector had a far wider range of health facilities than private sector, which was mainly due to the number of clinics. In South Backa district private sector had 323 practices, the district of Belgrade 655 and Nisava and Toplica district 173. Seventeen times more visits to households (4,650,423 vs. 267,356) and 111 times greater number of hospital days was provided in public health sector as compared to private health sector (781,083 vs. 7,023) in South Backa district. Conclusion. The conclusion of this analysis was that public health sector has remained the foundation of health care system in Serbia. Private health sector is expanding, but its structure and scope of services is still undervalued as compared to public sector.

Introduction. Mechanical instrumentation of the complex root canal system is very demanding procedure which requires use of the various manual and rotary instruments. The aim of this study was to assess the frequency and to verify the possible deformation of the working part of endodontic instruments after their multiple clinical use. Material and Methods. New sets of the manual endodontic instruments (reamers, K-files and Hedstroem) used in routine clinical use (44 instruments) and for root canal instrumentation of extracted teeth (44 instruments) were included in the study. Instrumentation was performed by Step-Back technique and constant irrigation with 0.5% NaOCl solution, 10 ml for each root canal. All the instruments were used 10 times and after use sterilized in a dry sterilizer or autoclave. The working parts of deformed instruments were analyzed using optimagnetic print. Results. The results obtained after clinical use showed deformations of the working part of the reamers in 50%, K-files in 43% and Hedstroem in 66.7% of used instruments. After instrumentation the canal of the extracted teeth, deformations were observed in 87.5% of the reamers, in 50% of the K-files and in 62.5% of Hedstroem files. The difference in frequency of the deformations was not statistically significant. On the instruments used for the preparation the canals of the extracted teeth and sterilized in autoclave, malformations were observed in 86.4%, comparing to the instruments sterilized in a dry sterilizer where malformations of the working part were registered in 59.1% of the cases. That difference was statistically significant (χ2=5.250; p=0.072). Conclusion. Multiple use of the manual endodontic instruments in clinical conditions leads to increased frequency of malformations of the working part in all types of manual endodontic instruments.

Introduction. Serbian Dental Journal (SDJ) is a major source of formal communication for dentists in this region. The purpose of this bibliometric study was to examine articles published in SDJ in period 2002-2009, in reference to journal productivity and nature of authorships, citation patterns, most frequently cited scientific journals and the role of self-citations. Material and Methods. Bibliographic data, as well as metadata for all articles were taken from the Serbian national citation index SCIndeks. Bibliometric analysis of source articles included the number and type of article, author characteristics and cited literature. For each citation the following data was recorded: author(s), article title, journal title, monographic title, publication type, publication year and language. Results. In this period 193 articles were published and most of them were original research articles. In this period a total of 314 national and international authors cooperated, responsible for 538 authorships. The mean number of authors per article was 2.8. Most cited items in terms of publication type were journal articles (83.5 %), while the most frequently cited journals were just those most relevant in the field of dentistry. Results also indicate that the age of the cited literature is below the norm for medical literature. Conclusion. Obtained numerical indicators do not differ significantly when compared to other scientific and professional journals. However, it can be concluded that it is necessary to increase journal productivity and self-citation rate, as well as citation of current literature, up to five years old. This analysis allows evaluating patterns of scientific communication among dentists in this region, as well as journal's current management strategies in order to define useful future directions for the inclusion into the international system of scientific information exchange.

Introduction. Primary health care in the Republic of Serbia is predominantly funded by the Republic Health Insurance Fund (RHIF). From the total income of health centers and institutes at the primary level, with no pharmacy and pharmacies (Kosovo excluded), 84% in 2008 was paid by RHIF. Frequency of participation ranged from 63-95% and it was stable in all observed years. The aim of this study was to determine the expenditures for primary health care for each insured person in statistically defined districts in the Republic of Serbia, with an emphasis on prevention participation. Material and Methods. Retrospective and comparative analysis of health statistics from the database of the Institute of Public Health of Serbia (IPHS) and financial data from the RHIF for the period 2006-2008 was done. Results. Observed by the districts in 2008, in Vojvodina, the lowest expenditure for primary health care had North Backa District (5,207 RSD) and greatest was in West Backa District (6,632 RSD) per capita. In the central Serbia territorial difference was much greater, ranging from 3,574 RSD in the District Morava to 6,701 RSD per capita in the District Toplica and Nisava. Expenditures for direct health care of RHIF per capita in the reporting period continuously have grown. Conclusion. The results showed that the largest cost for primary care for the insured person in the districts of Serbia was registered in the Nisava and Toplica (6,701 RSD) and lowest in the district of Morava (3,574 RSD) per capita.

Laser Doppler is a noninvasive, objective, reproducible and painless method for measuring blood flow in tissue microcirculation. This method is based on the Doppler effect, the change in frequency of light reflecting from blood cells in motion. Light from helium-neon laser through optical fibers and probes is directed to the surface of the tissue in which the flow is measured. Light portion is reflected from the cells in motion and changes the frequency while another portion is reflected from the static tissue maintaining the same frequency as the initial light. The total reflected light, with changed and original frequency, reaches photo detector in the same probe where the emitter is and it is transformed into electrical impulse. In the orofacial region the laser Doppler method is used to examine blood flow in the mandible, teeth pulp and masticator muscles. A significant drawback of the laser Doppler method is its sensitivity to the ambient conditions during measuring and the fact that blood flow is measured in all blood vessels of examined microregion. Therefore, the circulation of isolated individual blood vessels can not be monitored. Laser Doppler method can give reliable indicators of blood flow in mouth tissue and method is acceptable for the patients.

Introduction. For a long time, The Institute for Scientific Information (ISI, now Thomson Scientific, Philadelphia, US) citation databases, available online through the Web of Science (WoS), had an unique position among bibliographic databases. The emergence of new citation databases, such as Scopus and Google Scholar (GS), call in question the dominance of WoS and the accuracy of bibliometric and citation studies exclusively based on WoS data. The aim of this study was to determine whether there were significant differences in the received citation counts for Serbian Dental Journal (SDJ) found in WoS and Scopus databases, or whether GS results differed significantly from those obtained by WoS and Scopus, and whether GS could be an adequate qualitative alternative for commercial databases in the impact assessment of this journal. Material and Methods. The data regarding SDJ citation was collected in September 2010 by searching WoS, Scopus and GS databases. For further analysis, all relevant data of both, cited and citing articles, were imported into Microsoft Access® database. Results. One hundred and fifty-eight cited papers from SDJ and 249 received citations were found in the three analyzed databases. 74% of cited articles were found in GS, 46% in Scopus and 44% in WoS. The greatest number of citations (189) was derived from GS, while only 15% of the citations, were found in all three databases. There was a significant difference in the percentage of unique citations found in the databases. 58% originated from GS, while Scopus and WoS gave 6% and 4% unique citations, respectively. The highest percentage of databases overlap was found between WoS and Scopus (70%), while the overlap between Scopus and GS was 18% only. In case of WoS and GS the overlap was 17%. Most of the SDJ citations came from original scientific articles. Conclusion. WoS, Scopus and GS produce quantitatively and qualitatively different citation counts for SDJ articles. None of the examined databases can provide a comprehensive picture and it is necessary to take into account all three available sources.

In the last century a great progress was noted in all scientific disciplines. With the increasing number of scientific research, researchers and investment, the number of publications has grown exponentially. Besides, the development of information technologies and the emergence of the Internet, communication between scientists as well as the traditional roles assigned to the institutions responsible for information processing and provision has been changed. Due to the rapidly increasing subscription rates, libraries, although the primary participants in the scholarly communication process, lose their ability to meet user information needs. In order to overcome commercialization of scholarly publishing, libraries intensify use of different electronic resources, coordinate acquisition policy and form consortia. In November 2001, leading research libraries in Serbia launched an initiative to form the Consortium for Coordinated Acquisition of Serbian Libraries (KoBSON). Subscribed services, funded by the Ministry of Science and Technological Development of Serbia, currently include over 35,000 scientific journals, about 40,000 books and several citation databases. In the field of Dentistry, Oral Surgery and Medicine, 73.4% of total number of the most relevant dental journals is available in electronic form to Serbian academic community. This article presents a comprehensive overview of basic information about available journals: impact factor, productivity, publication continuity and frequency, language, services that they are available through, size of archives and existing formats. At present Serbian academic institutions have access to more than two thirds of the world’s most relevant dental journals, which justifies the Consortium founders’ initial idea of wide accessibility of scientific information and requires greater involvement of librarians in introducing available services to researchers in order to ensure their full utilization.

The prognosis of endodontically treated teeth depends not only on the success of the endodontic treatment, but also on the type of reconstruction. The use of fiber-reinforced resin (FRR) posts to restore endodontically treated teeth has gained popularity due to its mechanical and esthetic characteristics as well as properties of modern adhesive systems. The aim of this article was to show a clinical technique to reconstruct endodontically treated teeth with great loss of tooth structure using direct fiber-reinforced post systems and direct composite restorations. The first case was a patient with the fractured right second lower premolar. The tooth was endodontically treated and reconstructed thereafter. After the preparation of the root canal and cementation of a FRR post, particular attention was paid to the incremental and curing techniques adopted to reconstruct coronal part of the tooth. The second case was a patient with the fractured first right lower incisor. This tooth was treated in the same way. Direct composite reconstruction of endodontically treated teeth is an alternative to the prosthodontic therapy and can postpone prosthodontic therapy for a long time.

Introduction. A lack of appropriate adhesiveness is one of the biggest problems in the restorative dentistry today and the main cause of the microleakage between restorations and hard dental tissue. The aim of this study was to assess the adhesiveness of two different glass ionomer cement restorations class V on the hard dental tissue using the SEM analysis and dye penetration test. Material and methods. The study included 80 extracted teeth for orthodontic reasons (premolars and molars) in both genders and different age. On the vestibular and oral side of the teeth, adhesive preparations class V were done (size 3Ч2Ч2 mm). On the vestibular preparation, GC Fuji II was applicated and GC Fuji II LC-improved on the oral side. The quality of the adhesiveness between restorations and hard dental tissue was evaluated using the SEM analysis and dye penetration test (0.5% basic fuxsin). Linear penetration of the dye was observed using 10 times magnification. Results. The results showed that microleakage was presented with both materials but a ratio was less with Fuji II LC compared with Fuji II. Also, the microleakage was less on the occlusal parts of the restorations than on the gingival, with both materials. Microleakage was noticed in 93.44% teeth with Fuji II GJC restorations with index of microleakage of 148 on all edges. Fuji II LC GJC restorations showed microleakage in 68.4% teeth with index of microleakage 75 on all edges. The SEM analysis showed that both glass ionomer materials had better adhesiveness to the enamel than to the dentin. The average gap length between Fuji II LC and dentin was 9 μm and Fuji II 17 μm, respectively. Conclusion. Better adhesiveness to the hard dental tissue was achieved with materials of the newer generations, resin modificated glas ionomer cements.