The objective of this study was observation of the adhesive interface on original tooth samples, ... more The objective of this study was observation of the adhesive interface on original tooth samples, as well as their epoxy replicas, under SEM. A light‐cure flowable composite was incrementally placed and light‐polymerized in previously prepared cylindrical dentinal cavities on the buccal surfaces of extracted human third molars. After finishing procedures, impressions of the composite/dentin margin were made using polyvinylsiloxane in order to obtain accurate epoxy replicas for SEM analysis. Ultrastructural morphology of the adhesive surface was observed at high magnifications (≥1,000×) on original tooth samples, which were previously prepared to expose the part of the dentin surface, which participates in the formation of adhesive bond. SEM micrographs showed that marginal adaptation was mostly of acceptable quality. In some of the SEM micrographs of original tooth samples, marginal gap formation, and resin tag breakdown were noted, which were ascribed to polymerization shrinkage. Pr...
The study goal was to provide an overview of antibiotic prescribing practices of Serbian dentists... more The study goal was to provide an overview of antibiotic prescribing practices of Serbian dentists when treating endodontic infections and to disseminate the current ESE (European Society of Endodontology) recommendations to the study participants. A link to an online questionnaire was sent to 628 Serbian dentists whose email addresses were publicly available on the Internet, 158 of whom responded to the survey, resulting in a 25.16% response rate. The significance of possible associations was assessed via the Chi-squared test and Cramer’s V measure of association, with p < 0.05 considered as statistically significant. According to the study findings, 55.7% of respondents prescribed a 5-day antibiotic course. Moreover, Amoxicillin 500 mg was the first-choice antibiotic for 55.1% of the respondents, followed by Clindamycin 600 mg (18.4%). For patients allergic to penicillin, 61.4% of respondents prescribed Clindamycin. Statistically significant differences emerged only in relation ...
Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha m... more Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (PrimeB Vrat zuba + patologija; Zubna gleđ; Trajna zubna nadoknada; Kompomeri; Kompoziti
PURPOSE To verify the influence of placement and polymerization technique on the gap width betwee... more PURPOSE To verify the influence of placement and polymerization technique on the gap width between dentin and composite restoration. METHODS Standardized cylindrical cavities (3 mm in diameter, 2 mm deep) with all margins in dentin were prepared on buccal and oral surfaces of 30 extracted human third molars. With regard to the different resin composite filling techniques used, the samples were randomly divided into three groups (n=20): bulk; incremental; pin. Each group was further subdivided into subgroups based on different light polymerization techniques): continuous (40 seconds); discontinuous (2 seconds of activation, followed by 10 seconds of dark interval, then light polymerization continued for 38 seconds). After finishing procedures, impressions were made using polyvinylsiloxane, and epoxy resin replicas were obtained and prepared for scanning electron microscopy. The percentage of the marginal gaps in relation to the whole margin was recorded and statistically analyzed (P)...
Background/Aim. After removal of caries-infected dentin, a considerable area of the cavity floor ... more Background/Aim. After removal of caries-infected dentin, a considerable area of the cavity floor comprising caries- affected dentin. Bonding to caries-affected dentin is characterized by lower bound strength and inferior hybrid layer guality compared to bonding to sound dentin. The purpose of study was to compare shear bond strength (SBS) of currently available adhesive systems to sound dentin (SD) and caries-affected dentin (CAD) and elucidate the hybrid layer micromorphology. Methods. Sixty extracted human molars with coronal carious lesions formed the experimental sample while additional sixty extracted intact human molars (impacted third molars) served as controls. Identification of a carious-affected dentin was carried out using visual identification (North Carolina Dentin Sclerosis Scale). Teeth from both the experimental and the control sample were allocated to one of the following three groups: Adper Single Bond Plus/Filtek Supreme XT (ASB/FS) (3M ESPE), AdheSE One/Tetric Ev...
Summary Introduction Separation of instruments in the root canal is one of the challenges in endo... more Summary Introduction Separation of instruments in the root canal is one of the challenges in endodontic treatment. More specifically, nickel-titanium (NiTi) rotary instruments usually separate without previous deformation. The aim of this pilot study was to assess the effect of torsional stress on endodontic NiTi rotary instruments separation in simulated clinical conditions. Materials and methods Research was conducted on a sample of 20 human teeth in laboratory conditions. Experimental procedure consisted of determining canal curvatures for each root on digital radiographs and root canal treatment using endodontic NiTi rotary instruments. Out of 20 teeth (60 canals), two groups were formed with similar root canal curvatures (10 pairs of teeth) and instrumented using NiTi rotary instrument with or without torque control. Results Wilcoxon matched pair test showed no statistically significant difference in average number of instruments use with or without torque control (p>0.05). ...
Objectives: The purpose of this study was to examine cycle fatigue of Ni-Ti rotary endodontic ins... more Objectives: The purpose of this study was to examine cycle fatigue of Ni-Ti rotary endodontic instruments subjected to artificial root canals with different curvatures and to determine a mathematical model connecting lifespan of the instrument with the curvature to which it is subjected. Methods: We used a new mathematical model for the deformation of Ni-Ti material, showing that the maximal stress in a bent Ni-Ti endodontic instrument is not necessarily at the outer layer of the instrument. On the basis of this observation we modified Coffin-Manson relation so that a parameter corresponding to the position of the maximal stress within the instrument is introduced. Experiments were performed to determine coefficients in the modified Coffin-Manson relation. Twenty Ni-Ti rotary endodontic instruments BioRaCe (BR3 FKG Dentaire S.A., Chaux-de-Fonds, Switzerland) with tip size 25, 0.06 taper were subjected to the rotating-bending fatigue in an artificial root canals manufactured for cycl...
In this study we analyze viscoelastic properties of three flowable (Wave, Wave MV, Wave HV) and o... more In this study we analyze viscoelastic properties of three flowable (Wave, Wave MV, Wave HV) and one universal hybrid resin (Ice) composites, prior to setting. We developed a mathematical model containing fractional derivatives in order to describe their properties. Isothermal experimental study was conducted on a rheometer with parallel plates. In dynamic oscillatory shear test, storage and loss modulus, as well as the complex viscosity where determined. We assumed four different fractional viscoelastic models, each belonging to one particular class, derivable from distributed-order fractional constitutive equation. The restrictions following from the Second law of thermodynamics are imposed on each model. The optimal parameters corresponding to each model are obtained by minimizing the error function that takes into account storage and loss modulus, thus obtaining the best fit to the experimental data. In the frequency range considered, we obtained that for Wave HV and Wave MV there exist a critical frequency for which loss and storage modulus curves intersect, defining a boundary between two different types of behavior: one in which storage modulus is larger than loss modulus and the other in which the situation is opposite. Loss and storage modulus curves for Ice and Wave do not show this type of behavior, having either elastic, or viscous effects dominating in entire frequency range considered. The developed models may be used to predict behavior of four tested composites in different flow conditions (different deformation speed), thus helping to estimate optimal handling characteristics for specific clinical applications.
Sažetak -Cilj ove jednogodišnje prospektivne kliničke studije bila je ocena terapijskog uspeha mi... more Sažetak -Cilj ove jednogodišnje prospektivne kliničke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (Prime&Bond® NT/Dentsply/De Trey, Konstanz, Germany) i kompomera (Dyract® eXtra/Dentsply/De Trey, Konstanz, Germany) u kombinaciji s jednofaznim samonagrizajućim adhezivnim sistemom (Xeno® III/ Dentsply/De Trey, Konstanz, Germany) u sanaciji nekarijesnih cervikalnih lezija. Kriterijum za uključivanje pacijenata u studiju bio je da su defekti tvrdog zubnog tkiva predstavljeni s najmanje jednim parom nekarijesnih cervikalnih lezija minimalne dubine 1 mm, nezavisno od lokalizacije u zubnom nizu. Postavljeno je ukupno 60 ispuna kod 30 pacijenata, pri čemu je svaki pacijent dobio ispune od oba ispitivana materijala. Klinička evaluacija terapijskog uspeha izvedena je nakon šest meseci i godinu dana od datuma postavljanja ispuna, uz upotrebu modifikovanih United States Public Health Service kriterijuma. Vrednovani su: retencija ispuna, pojava marginalne pukotine, marginalna prebojenost, trošenje, postoperativna osetljivost i pojava sekundarnog karijesa. Statistički znatno viši procenat ispuna/zuba kod kojih je dijagnostikovana postoperativna osetljivost zabeležen je u grupi kompozitnih ispuna nakon šest meseci. Na kraju evaluacionog perioda, nakon godinu dana, nije zabeležena statistički značajna razlika ni u jednom kriterijumu između ispitanih grupa adhezivnih estetskih materijala. Rezultati ove studije pokazuju identičan kvalitet kompozitnih i kompomernih ispuna godinu dana nakon sanacije nekarijesnih cervikalnih lezija.
Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha m... more Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (PrimeB Vrat zuba + patologija; Zubna gleđ; Trajna zubna nadoknada; Kompomeri; Kompoziti
Introduction. The ultimate goal in restorative dentistry has always been to achieve strong and pe... more Introduction. The ultimate goal in restorative dentistry has always been to achieve strong and permanent bond between the dental tissues and filling materials. It is not easy to achieve this task because the bonding process is different for enamel and dentin - dentin is more humid and more organic than enamel. It is moisture and organic nature of dentin that make this hard tissue very complex to achieve adhesive bond. One of the first and most widely used tools for examining the adhesive bond between hard dental tissues and composite restorative materials is scanning electron microscopy. The aim of this study was scanning electron microscopy analyzes the interfacial micro morphology of total-etch and self-etch adhesives. Material and Methods. Micro morphological characteristics of interface between totaletch adhesive (Prime & Bond NT) in combination with the corresponding composite (Ceram X Mono) were compared with those of self-etching adhesive (AdheSE One) in combination with the ...
The aim of this study was to analyse the interfacial micromorphology of total‐etch adhesives and ... more The aim of this study was to analyse the interfacial micromorphology of total‐etch adhesives and dentin structures different locations by using SEM. Standardized cylindrical cavities (3mm in diameter, 2mm deep) with all margins in dentin were prepared on occlusal and buccal surfaces of twenty extracted human third molars. A total‐etch dentin adhesive system and a light‐cure flowable composite (Filtek Ultimate Flowable, 3M ESPE, St. Paul, MN, USA) were used in this study. Micro‐morphological SEM analysis of the marginal seal of the original tooth specimens was performed using high magnification of up to 1000×. In this study, we found the difference in interfacial micromorphology in dentin different locations. Also, marginal gap was found in both observed dentin area. Better understanding of complexity and three‐ dimensional variations of the tooth structure is important for prevention of clinical challenges such as postoperative sensitivity, marginal discoloration and secondary caries, which could be prevented by achieving of predictable and long‐lasting adhesive bond.
The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotar... more The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotary nickel-titanium (Ni-Ti) endodontic instruments. Simulated root canals with different curvatures were used to determine a relation between canal curvature and instrument lifespan. Using a novel mathematical model for the deformation of pseudoelastic Ni-Ti alloy, it was shown that maximum stress need not necessarily occur at the outer layer. On the basis of this observation, the Coffi n-Manson relation was modifi ed with parameters determined from this experiment. Results showed that the number of cycles to failure was infl uenced by the angle and radius of canal curvature and the size of instrument at the beginning of canal curvature. The resulting quantitative mathematical relation could be used to predict the lifespan of rotary Ni-Ti endodontic instruments under clinical conditions and thereby reduce the incidence of instrument failure in vivo.
The aim of this study is to develop fractional derivative models for the assessment of viscoelast... more The aim of this study is to develop fractional derivative models for the assessment of viscoelastic properties related to handling characteristics of dental resin composites belonging to two classes: flowable (Revolution Formula 2 and Filtek Ultimate) and posterior &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; flowable base (Smart Dentin Replace). Rheological measurements on all materials tested in this study were performed using dynamic oscillatory rheometer at temperature of 23°C. A parallel plates module with a diameter of 20mm was used to measure the properties of the resin composites tested. We developed two models to describe the obtained data: the generalized Newton model and the generalized Zener model (the so-called three parameter model). Both models contain fractional derivatives of Riemann-Liouville type. By determining the parameters of the model we were able to fit experimental data with high accuracy. Our results show that flowable &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; resin-composite material (SDR) has distinct properties as compared to other two flowable resin composite materials (Revolution Formula 2 and Filtek Ultimate). Thus, previously found SDR properties as &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; flowable base results in the fact that it is described by generalized Zener model (i.e., it has properties of solid like viscoelastic material). Our model may be used to predict behavior of tested composites in different flow conditions. The SDR has initially small almost constant complex viscosity showing that it has good self-leveling property.
The aim of this two-year prospective clinical study was to evaluate and compare the clinical perf... more The aim of this two-year prospective clinical study was to evaluate and compare the clinical performance of three different adhesive esthetic materials in noncarious cervical lesions. A total of 90 restorations (30 per material) were placed in 30 patients who ranged in age between 18 and 50 years and of both genders, by a single operator with no previous preparation. The restoration of noncarious cervical lesions was done with either a microfilled composite (Esthet.X/Dentsply/De Trey, Konstanz, Germany, and Prime&amp;Bond NT/Dentsply/De Trey), a nanohybrid composite (TetricEvoCeram/Vivadent, Schaan, Liechtenstein, and AdheSE/Vivadent), or a compomer (Dyract eXtra/Dentsply/De Trey and Xeno III Dentsply/De Trey). All restorations were evaluated by independent examiners using a modified US Public Health Service criteria at baseline and after 12 and 24 months for six clinical categories. Data were analyzed statistically by Pearson&#39;s chi-square or the Fisher&#39;s exact test at 5% significance level (p&lt;0.05). Results showed that most of the restorations were clinically satisfactory after 12 and 24 months, with no statistically significant differences among the three groups for all evaluated criteria. Treatment of noncarious cervical lesions using composite and compomer materials, combined with the appropriate adhesive systems and properly implemented restorative procedures, gives satisfactory results after a two-year evaluation period.
Gled -predstavlja najtvrde tkivo covckovog Ofganizma. Bez obzira na visok procenat mineralnih faz... more Gled -predstavlja najtvrde tkivo covckovog Ofganizma. Bez obzira na visok procenat mineralnih faza II njegovoj strukturi (96%) gled poseduje semipermeabilnost. Ona je posledica postojanja organskog matriksa (prizmaticne ovojnice koja okruzuje svaki kristal posebno te tako postaje organ ski meduprostor vise nego strukturalni entitet [7]. Voda sa rastvorenim malim molekulirna prolazi kroz organski deo izrnedu glednih kristala i uspostavlja fluidni tok, koji se nalazi u direktnoj zavisnosti od morfologije zuba i zivotnog doba pacijenta. Gledna permeabi Inost opada starenjem jer organski kanal i bivaju zatvoreni depozicijom kristala kao i formiranjem biofilma na njegovoj spoljnoj povrsini. Gled je izgradena od glednih prizmi koje ako ne podlegnu adekvatnoj mineralizaciji dovode do pojave glednih defekata sto povecava fluidni tok gledi.
The objective of this study was observation of the adhesive interface on original tooth samples, ... more The objective of this study was observation of the adhesive interface on original tooth samples, as well as their epoxy replicas, under SEM. A light‐cure flowable composite was incrementally placed and light‐polymerized in previously prepared cylindrical dentinal cavities on the buccal surfaces of extracted human third molars. After finishing procedures, impressions of the composite/dentin margin were made using polyvinylsiloxane in order to obtain accurate epoxy replicas for SEM analysis. Ultrastructural morphology of the adhesive surface was observed at high magnifications (≥1,000×) on original tooth samples, which were previously prepared to expose the part of the dentin surface, which participates in the formation of adhesive bond. SEM micrographs showed that marginal adaptation was mostly of acceptable quality. In some of the SEM micrographs of original tooth samples, marginal gap formation, and resin tag breakdown were noted, which were ascribed to polymerization shrinkage. Pr...
The study goal was to provide an overview of antibiotic prescribing practices of Serbian dentists... more The study goal was to provide an overview of antibiotic prescribing practices of Serbian dentists when treating endodontic infections and to disseminate the current ESE (European Society of Endodontology) recommendations to the study participants. A link to an online questionnaire was sent to 628 Serbian dentists whose email addresses were publicly available on the Internet, 158 of whom responded to the survey, resulting in a 25.16% response rate. The significance of possible associations was assessed via the Chi-squared test and Cramer’s V measure of association, with p < 0.05 considered as statistically significant. According to the study findings, 55.7% of respondents prescribed a 5-day antibiotic course. Moreover, Amoxicillin 500 mg was the first-choice antibiotic for 55.1% of the respondents, followed by Clindamycin 600 mg (18.4%). For patients allergic to penicillin, 61.4% of respondents prescribed Clindamycin. Statistically significant differences emerged only in relation ...
Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha m... more Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (PrimeB Vrat zuba + patologija; Zubna gleđ; Trajna zubna nadoknada; Kompomeri; Kompoziti
PURPOSE To verify the influence of placement and polymerization technique on the gap width betwee... more PURPOSE To verify the influence of placement and polymerization technique on the gap width between dentin and composite restoration. METHODS Standardized cylindrical cavities (3 mm in diameter, 2 mm deep) with all margins in dentin were prepared on buccal and oral surfaces of 30 extracted human third molars. With regard to the different resin composite filling techniques used, the samples were randomly divided into three groups (n=20): bulk; incremental; pin. Each group was further subdivided into subgroups based on different light polymerization techniques): continuous (40 seconds); discontinuous (2 seconds of activation, followed by 10 seconds of dark interval, then light polymerization continued for 38 seconds). After finishing procedures, impressions were made using polyvinylsiloxane, and epoxy resin replicas were obtained and prepared for scanning electron microscopy. The percentage of the marginal gaps in relation to the whole margin was recorded and statistically analyzed (P)...
Background/Aim. After removal of caries-infected dentin, a considerable area of the cavity floor ... more Background/Aim. After removal of caries-infected dentin, a considerable area of the cavity floor comprising caries- affected dentin. Bonding to caries-affected dentin is characterized by lower bound strength and inferior hybrid layer guality compared to bonding to sound dentin. The purpose of study was to compare shear bond strength (SBS) of currently available adhesive systems to sound dentin (SD) and caries-affected dentin (CAD) and elucidate the hybrid layer micromorphology. Methods. Sixty extracted human molars with coronal carious lesions formed the experimental sample while additional sixty extracted intact human molars (impacted third molars) served as controls. Identification of a carious-affected dentin was carried out using visual identification (North Carolina Dentin Sclerosis Scale). Teeth from both the experimental and the control sample were allocated to one of the following three groups: Adper Single Bond Plus/Filtek Supreme XT (ASB/FS) (3M ESPE), AdheSE One/Tetric Ev...
Summary Introduction Separation of instruments in the root canal is one of the challenges in endo... more Summary Introduction Separation of instruments in the root canal is one of the challenges in endodontic treatment. More specifically, nickel-titanium (NiTi) rotary instruments usually separate without previous deformation. The aim of this pilot study was to assess the effect of torsional stress on endodontic NiTi rotary instruments separation in simulated clinical conditions. Materials and methods Research was conducted on a sample of 20 human teeth in laboratory conditions. Experimental procedure consisted of determining canal curvatures for each root on digital radiographs and root canal treatment using endodontic NiTi rotary instruments. Out of 20 teeth (60 canals), two groups were formed with similar root canal curvatures (10 pairs of teeth) and instrumented using NiTi rotary instrument with or without torque control. Results Wilcoxon matched pair test showed no statistically significant difference in average number of instruments use with or without torque control (p>0.05). ...
Objectives: The purpose of this study was to examine cycle fatigue of Ni-Ti rotary endodontic ins... more Objectives: The purpose of this study was to examine cycle fatigue of Ni-Ti rotary endodontic instruments subjected to artificial root canals with different curvatures and to determine a mathematical model connecting lifespan of the instrument with the curvature to which it is subjected. Methods: We used a new mathematical model for the deformation of Ni-Ti material, showing that the maximal stress in a bent Ni-Ti endodontic instrument is not necessarily at the outer layer of the instrument. On the basis of this observation we modified Coffin-Manson relation so that a parameter corresponding to the position of the maximal stress within the instrument is introduced. Experiments were performed to determine coefficients in the modified Coffin-Manson relation. Twenty Ni-Ti rotary endodontic instruments BioRaCe (BR3 FKG Dentaire S.A., Chaux-de-Fonds, Switzerland) with tip size 25, 0.06 taper were subjected to the rotating-bending fatigue in an artificial root canals manufactured for cycl...
In this study we analyze viscoelastic properties of three flowable (Wave, Wave MV, Wave HV) and o... more In this study we analyze viscoelastic properties of three flowable (Wave, Wave MV, Wave HV) and one universal hybrid resin (Ice) composites, prior to setting. We developed a mathematical model containing fractional derivatives in order to describe their properties. Isothermal experimental study was conducted on a rheometer with parallel plates. In dynamic oscillatory shear test, storage and loss modulus, as well as the complex viscosity where determined. We assumed four different fractional viscoelastic models, each belonging to one particular class, derivable from distributed-order fractional constitutive equation. The restrictions following from the Second law of thermodynamics are imposed on each model. The optimal parameters corresponding to each model are obtained by minimizing the error function that takes into account storage and loss modulus, thus obtaining the best fit to the experimental data. In the frequency range considered, we obtained that for Wave HV and Wave MV there exist a critical frequency for which loss and storage modulus curves intersect, defining a boundary between two different types of behavior: one in which storage modulus is larger than loss modulus and the other in which the situation is opposite. Loss and storage modulus curves for Ice and Wave do not show this type of behavior, having either elastic, or viscous effects dominating in entire frequency range considered. The developed models may be used to predict behavior of four tested composites in different flow conditions (different deformation speed), thus helping to estimate optimal handling characteristics for specific clinical applications.
Sažetak -Cilj ove jednogodišnje prospektivne kliničke studije bila je ocena terapijskog uspeha mi... more Sažetak -Cilj ove jednogodišnje prospektivne kliničke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (Prime&Bond® NT/Dentsply/De Trey, Konstanz, Germany) i kompomera (Dyract® eXtra/Dentsply/De Trey, Konstanz, Germany) u kombinaciji s jednofaznim samonagrizajućim adhezivnim sistemom (Xeno® III/ Dentsply/De Trey, Konstanz, Germany) u sanaciji nekarijesnih cervikalnih lezija. Kriterijum za uključivanje pacijenata u studiju bio je da su defekti tvrdog zubnog tkiva predstavljeni s najmanje jednim parom nekarijesnih cervikalnih lezija minimalne dubine 1 mm, nezavisno od lokalizacije u zubnom nizu. Postavljeno je ukupno 60 ispuna kod 30 pacijenata, pri čemu je svaki pacijent dobio ispune od oba ispitivana materijala. Klinička evaluacija terapijskog uspeha izvedena je nakon šest meseci i godinu dana od datuma postavljanja ispuna, uz upotrebu modifikovanih United States Public Health Service kriterijuma. Vrednovani su: retencija ispuna, pojava marginalne pukotine, marginalna prebojenost, trošenje, postoperativna osetljivost i pojava sekundarnog karijesa. Statistički znatno viši procenat ispuna/zuba kod kojih je dijagnostikovana postoperativna osetljivost zabeležen je u grupi kompozitnih ispuna nakon šest meseci. Na kraju evaluacionog perioda, nakon godinu dana, nije zabeležena statistički značajna razlika ni u jednom kriterijumu između ispitanih grupa adhezivnih estetskih materijala. Rezultati ove studije pokazuju identičan kvalitet kompozitnih i kompomernih ispuna godinu dana nakon sanacije nekarijesnih cervikalnih lezija.
Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha m... more Sažetak – Cilj ove jednogodisnje prospektivne klinicke studije bila je ocena terapijskog uspeha mikropunjenog kompozita (Esthet.X®/ Dentsply/De Trey, Konstanz, Germany) u kombinaciji s dvofaznim adhezivnim sistemom (PrimeB Vrat zuba + patologija; Zubna gleđ; Trajna zubna nadoknada; Kompomeri; Kompoziti
Introduction. The ultimate goal in restorative dentistry has always been to achieve strong and pe... more Introduction. The ultimate goal in restorative dentistry has always been to achieve strong and permanent bond between the dental tissues and filling materials. It is not easy to achieve this task because the bonding process is different for enamel and dentin - dentin is more humid and more organic than enamel. It is moisture and organic nature of dentin that make this hard tissue very complex to achieve adhesive bond. One of the first and most widely used tools for examining the adhesive bond between hard dental tissues and composite restorative materials is scanning electron microscopy. The aim of this study was scanning electron microscopy analyzes the interfacial micro morphology of total-etch and self-etch adhesives. Material and Methods. Micro morphological characteristics of interface between totaletch adhesive (Prime & Bond NT) in combination with the corresponding composite (Ceram X Mono) were compared with those of self-etching adhesive (AdheSE One) in combination with the ...
The aim of this study was to analyse the interfacial micromorphology of total‐etch adhesives and ... more The aim of this study was to analyse the interfacial micromorphology of total‐etch adhesives and dentin structures different locations by using SEM. Standardized cylindrical cavities (3mm in diameter, 2mm deep) with all margins in dentin were prepared on occlusal and buccal surfaces of twenty extracted human third molars. A total‐etch dentin adhesive system and a light‐cure flowable composite (Filtek Ultimate Flowable, 3M ESPE, St. Paul, MN, USA) were used in this study. Micro‐morphological SEM analysis of the marginal seal of the original tooth specimens was performed using high magnification of up to 1000×. In this study, we found the difference in interfacial micromorphology in dentin different locations. Also, marginal gap was found in both observed dentin area. Better understanding of complexity and three‐ dimensional variations of the tooth structure is important for prevention of clinical challenges such as postoperative sensitivity, marginal discoloration and secondary caries, which could be prevented by achieving of predictable and long‐lasting adhesive bond.
The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotar... more The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotary nickel-titanium (Ni-Ti) endodontic instruments. Simulated root canals with different curvatures were used to determine a relation between canal curvature and instrument lifespan. Using a novel mathematical model for the deformation of pseudoelastic Ni-Ti alloy, it was shown that maximum stress need not necessarily occur at the outer layer. On the basis of this observation, the Coffi n-Manson relation was modifi ed with parameters determined from this experiment. Results showed that the number of cycles to failure was infl uenced by the angle and radius of canal curvature and the size of instrument at the beginning of canal curvature. The resulting quantitative mathematical relation could be used to predict the lifespan of rotary Ni-Ti endodontic instruments under clinical conditions and thereby reduce the incidence of instrument failure in vivo.
The aim of this study is to develop fractional derivative models for the assessment of viscoelast... more The aim of this study is to develop fractional derivative models for the assessment of viscoelastic properties related to handling characteristics of dental resin composites belonging to two classes: flowable (Revolution Formula 2 and Filtek Ultimate) and posterior &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; flowable base (Smart Dentin Replace). Rheological measurements on all materials tested in this study were performed using dynamic oscillatory rheometer at temperature of 23°C. A parallel plates module with a diameter of 20mm was used to measure the properties of the resin composites tested. We developed two models to describe the obtained data: the generalized Newton model and the generalized Zener model (the so-called three parameter model). Both models contain fractional derivatives of Riemann-Liouville type. By determining the parameters of the model we were able to fit experimental data with high accuracy. Our results show that flowable &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; resin-composite material (SDR) has distinct properties as compared to other two flowable resin composite materials (Revolution Formula 2 and Filtek Ultimate). Thus, previously found SDR properties as &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;bulk-fill&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; flowable base results in the fact that it is described by generalized Zener model (i.e., it has properties of solid like viscoelastic material). Our model may be used to predict behavior of tested composites in different flow conditions. The SDR has initially small almost constant complex viscosity showing that it has good self-leveling property.
The aim of this two-year prospective clinical study was to evaluate and compare the clinical perf... more The aim of this two-year prospective clinical study was to evaluate and compare the clinical performance of three different adhesive esthetic materials in noncarious cervical lesions. A total of 90 restorations (30 per material) were placed in 30 patients who ranged in age between 18 and 50 years and of both genders, by a single operator with no previous preparation. The restoration of noncarious cervical lesions was done with either a microfilled composite (Esthet.X/Dentsply/De Trey, Konstanz, Germany, and Prime&amp;Bond NT/Dentsply/De Trey), a nanohybrid composite (TetricEvoCeram/Vivadent, Schaan, Liechtenstein, and AdheSE/Vivadent), or a compomer (Dyract eXtra/Dentsply/De Trey and Xeno III Dentsply/De Trey). All restorations were evaluated by independent examiners using a modified US Public Health Service criteria at baseline and after 12 and 24 months for six clinical categories. Data were analyzed statistically by Pearson&#39;s chi-square or the Fisher&#39;s exact test at 5% significance level (p&lt;0.05). Results showed that most of the restorations were clinically satisfactory after 12 and 24 months, with no statistically significant differences among the three groups for all evaluated criteria. Treatment of noncarious cervical lesions using composite and compomer materials, combined with the appropriate adhesive systems and properly implemented restorative procedures, gives satisfactory results after a two-year evaluation period.
Gled -predstavlja najtvrde tkivo covckovog Ofganizma. Bez obzira na visok procenat mineralnih faz... more Gled -predstavlja najtvrde tkivo covckovog Ofganizma. Bez obzira na visok procenat mineralnih faza II njegovoj strukturi (96%) gled poseduje semipermeabilnost. Ona je posledica postojanja organskog matriksa (prizmaticne ovojnice koja okruzuje svaki kristal posebno te tako postaje organ ski meduprostor vise nego strukturalni entitet [7]. Voda sa rastvorenim malim molekulirna prolazi kroz organski deo izrnedu glednih kristala i uspostavlja fluidni tok, koji se nalazi u direktnoj zavisnosti od morfologije zuba i zivotnog doba pacijenta. Gledna permeabi Inost opada starenjem jer organski kanal i bivaju zatvoreni depozicijom kristala kao i formiranjem biofilma na njegovoj spoljnoj povrsini. Gled je izgradena od glednih prizmi koje ako ne podlegnu adekvatnoj mineralizaciji dovode do pojave glednih defekata sto povecava fluidni tok gledi.
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Papers by Igor Stojanac