MTA Angelus Research Articles

Color Changes of Teeth after Treatment with Various Mineral Trioxide Aggregate–based Materials: An Ex Vivo Study

IntroductionMineral trioxide aggregate (MTA) materials have been used for many years as a pulp therapy material. The most widely used product, ProRoot MTA (Dentsply, Tulsa, OK), has a major drawback in that it causes tooth discoloration. Alternatives have recently been developed such as ENDOCEM Zr (MARUCHI, Wonju, Korea) and RetroMTA (BioMTA, Seoul, Korea). The purpose of this study was to compare the discoloration of these various MTA-based materials. MethodsDiscoloration of discs prepared from 4 different MTA-based materials (ProRoot MTA, MTA Angelus [Angelus, Londrina, PR, Brazil], ENDOCEM Zr, and RetroMTA) were observed at 15 and 30 minutes after exposure to light at an intensity of 1000 mA/cm2. In a tooth model, 12 premolars were used per each group to retrofill the pulp chamber with MTA-based materials. The degree of discoloration was measured over a 16-week period using a digital spectrophotometer. ResultsDistinct color changes were observed for discs made from ProRoot MTA and MTA Angelus, but no clear change was observed for those made from either ENDOCEM Zr or RetroMTA. In the tooth model, more distinct, time-dependent color changes were observed for teeth filled with ProRoot MTA and MTA Angelus than for those filled with ENDOCEM Zr and RetroMTA. ConclusionsLess discoloration was observed with ENDOCEM Zr and RetroMTA (which contain zirconium oxide) than with ProRoot MTA and MTA Angelus (which contain bismuth oxide) in both of the test models used.

Calcium Silicate-Based Cements Associated with Micro- and Nanoparticle Radiopacifiers: Physicochemical Properties and Bioactivity.

Objective. The aim of this study was to evaluate the physicochemical properties and bioactivity of two formulations of calcium silicate-based cements containing additives (CSCM) or resin (CSCR), associated with radiopacifying agents zirconium oxide (ZrO2) and niobium oxide (Nb2O5) as micro- and nanoparticles; calcium tungstate (CaWO4); and bismuth oxide (Bi2O3). MTA Angelus was used as control. Methods. Surface features and bioactivity were evaluated by scanning electron microscopy and the chemical composition by energy dispersive X-ray spectrometry (EDS-X). Results. CSCM and CSCR presented larger particle sizes than MTA. Hydroxyapatite deposits were found on the surface of some materials, especially when associated with the radiopacifier with ZrO2 nanoparticles. All the cements presented calcium, silicon, and aluminum in their composition. Conclusion. Both calcium silicate-based cements presented composition and bioactivity similar to MTA when associated with the radiopacifiers evaluated.

Effect of Varying Water-to-Powder Ratios and Ultrasonic Placement on the Compressive Strength of Mineral Trioxide Aggregate

IntroductionThe purpose of this study was to compare the compressive strength of mineral trioxide aggregate (MTA) when mixed with 2 different water-to-powder (WP) proportions using either hand or ultrasonic placement. MethodsTooth-colored ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and white MTA Angelus (Angelus Soluçoes Odontologicas, Londrina, Brazil) were investigated. One gram of each MTA powder was mixed with either 0.34 or 0.40 g distilled water. The 4 groups were further divided into 2 groups of 5 specimens for each of the following techniques: conventional (ie, hand placement) and placement using indirect ultrasonic activation for 30 seconds. All specimens were subjected to compressive strength testing after 4 days. The results were statistically analyzed with multivariate analysis of variance and Tukey Honestly Significant Difference tests at a significance level of P < .05. ResultsThe mean compressive strength values of ProRoot MTA (84.17 ± 22.68) were significantly greater than those of MTA Angelus (47.71 ± 14.29) (P < .01). Specimens mixed with the 0.34 WP ratio had higher compressive strength values (72.85 ± 25.77) than those mixed with the 0.40 WP ratio (56.69 ± 24.85) (P < .05). The highest compressive strength values were recorded for ProRoot MTA specimens that were mixed in the 0.34 WP ratio, and then the samples were placed with ultrasonic activation (mean = 91.35 MPa). The lowest values were recorded for MTA Angelus samples that were mixed in the 0.40 WP ratio, and the specimens were placed without ultrasonic activation (mean = 36.36 MPa). Ultrasonic activation had no significant difference in terms of compressive strength. ConclusionsWhen using ProRoot MTA and MTA Angelus, higher WP ratios resulted in lower compressive strength values. Ultrasonication had no significant effect on the compressive strength of the material regardless of the WP ratio that was used. Therefore, adherence to the manufacturer's recommended WP ratio when preparing MTA for use in dental applications is advised.

Color Stabilities of Calcium Silicate–based Materials in Contact with Different Irrigation Solutions

IntroductionMineral trioxide aggregate (MTA) has been reported to cause tooth discoloration when applied in the esthetic zone. A previous study has shown discoloration of MTA in contact with root canal irrigation solutions. Moreover, there are limited data on color stability of novel calcium silicate–based materials. This study aimed to evaluate color changes of 4 calcium silicate–based materials in contact with different irrigation solutions. MethodsProRoot white MTA (Dentsply Tulsa Dental, Johnson City, TN), white MTA Angelus (Angelus Solucoes Odontologicas, Londrina, Brazil), Biodentine (Septodont, Saint Maur des Fosses, France), and BioAggregate (Innovative Bioceramix, Vancouver, BC, Canada) samples were assessed. Materials were mixed according to the manufacturers' instructions. Cylindric samples (10-mm diameter and 2-mm height) were obtained by curing in molds for each material's setting time at 100% humidity and 37°C. Each specimen was immersed in 5% sodium hypochlorite, 2% chlorhexidine gluconate, or distilled water for 24 hours. Color changes were measured with a spectrophotometer. Data were analyzed by using 2-way analysis of variance and post hoc Bonferroni tests. ResultsAll materials exhibited clinically perceptible discoloration when immersed in sodium hypochlorite and chlorhexidine gluconate. ProRoot white MTA showed a statistically significant difference from Bioaggregate, Biodentine, and white MTA Angelus. Distilled water did not cause clinically perceptible discoloration of any material. ConclusionsIn esthetically critical regions, compounds free of bismuth oxide, Biodentine, and BioAggregate can be considered as alternatives to MTA. However, all calcium silicate–based materials exhibited clinically perceptible color changes.

Analysis of marginal seal of ProRoot MTA, MTA Angelus biodentine, and glass ionomer cement as root-end filling materials: An in vitro study

Background: Search for a root-end filling material fulfilling all the ideal characteristics is an ongoing process. The present study aimed to evaluate the marginal seal of the following materials when used as root-end filling materials, MTA Angelus, White ProRoot MTA, Biodentine and Glass ionomer cement (GIC). Materials and Methods: Sixty single-rooted maxillary central incisors were included in the study. The crowns were resected followed by cleaning and shaping with hand files and protaper rotary files followed by obturation of the roots. The root ends were resected at 3 mm level. Then, root-end cavity preparation of 3 mm depth was done using ultrasonic tips. The samples were randomly divided into four groups of 15 each and cavities restored with, such as (1) Group 1: MTA Angelus, (2) Group 2: ProRoot MTA, (3) Group 3: Biodentine, and (4) Group 4: GIC. The root samples were coated with two coats of nail varnish and immersed in methylene blue dye 2% for 48 h. Longitudinal root resection was done. The depth of dye penetration was evaluated under the stereomicroscope to examine the extent of microleakage. The amount of dye penetration was measured in millimeters. The results were then statistically analyzed using one-way analysis of variance and post-hoc Tukey's test. Conclusion: Microleakage was present in all the samples. Least amount of apical dye microleakage was seen in biodentine with mean value of 0.16 mm followed by ProRoot MTA 0.68 mm, MTA Angelus 0.74 mm, and GIC 1.53 mm. The best sealing ability was seen in biodentine, and this difference was statistically significant.

Influence of addition of calcium oxide on physicochemical properties of Portland cement with zirconium or niobium oxide.

Context:Calcium oxide (CaO) may be added to mineral trioxide aggregate (MTA) or Portland cement (PC) to improve physicochemical and biological properties.Aims:To evaluate the physicochemical properties of PC associated with radiopacifiers and CaO.Materials and Methods:MTA Angelus, PC + 30% zirconium oxide (Zr), or 30% niobium oxide (Nb) associated with 10 or 20% of CaO were evaluated. Gilmore needles were used to evaluate initial and final setting time. Compressive strength was evaluated after the periods of 24 hours and 21 days. pH was analyzed after 3, 12, 24 hours, 7, 14, 21 days. Solubility and flow tests were performed based on the ISO 6876. The data obtained were submitted to analysis of variance and Tukey tests (P ≤ 0.05).Results:The associations with 10% CaO showed greater strength that the associations with 20% CaO. The shortest initial setting time was observed for the association PC + Zr + 20% CaO and MTA. All the cements presented alkaline pH. The flow of all cements was similar. The highest solubility was found in the associations with 20% CaO.Conclusion:The addition of CaO to PC favored the alkaline property and the PC + Zr + 20% CaO presented setting time similar to MTA.

Push-out bond strength of CPP-ACP-modified calcium silicate-based cements.

This study evaluated the push-out bond strength of 0%, 0.5%, 1.0%, 2.0% and 3.0% (w/w) casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified calcium silicate-based cements (CSCs). The push-out bond strength of a trial MTA was also compared with two CSCs (Biodentine(™) and Angelus(®) MTA). Three hundred 1 mm thick horizontal root sections were prepared from 60 singlerooted human teeth. The canal space of each section was enlarged and filled with the cements. The sections were stored in a phosphate buffer solution. After incubation for 2 months, the push-out bond strength was measured and the data were analyzed using one way analysis of variance followed by Tukey's test. The addition of CPP-ACP to the test cements increased the push-out bond strength (p<0.05). The push-out bond strength of Biodentine(™) was higher than the other cements (p<0.05). There was no statistically significant difference between Angelus(®) MTA and the trial MTA with most of CPP-ACP concentrations.

In vitro antibacterial activity of different pulp capping materials.

Background Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Material and Methods Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials. Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping materials were recorded and compared for each bacterial strain. Results For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition zones. Conclusions MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based materials which present an higher antibacterial activity. Key words:Agar disc diffusion test, antimicrobial activity, calcium hydroxide, MTA, pulp capping materials.

Calcium silicate and calcium hydroxide materials for pulp capping: biointeractivity, porosity, solubility and bioactivity of current formulations.

The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared. Calcium hydroxide-based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate-based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated. All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites. calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.

Influence of composition on setting kinetics of new injectable and/or fast setting tricalcium silicate cements

ObjectivesNew commercial tricalcium silicate based cements were elaborated to improve handling properties and setting time. The goals of the present work were: (i) to determine the composition of the new injectable and/or fast setting calcium silicate based cements, and (ii) to investigate the impact of the differences in composition on their setting kinetics. MethodsThe materials considered were Angelus MTA™, Biodentine™, MM-MTA™, MTA-Caps™, and ProRoot MTA™ as control.Elemental composition of materials was studied by Inductively Coupled Plasma-Atomic Emission Spectroscopy and X-ray Energy Dispersive analysis, whereas phases in presence were analyzed by Micro-Raman spectroscopy and X-ray Diffraction analysis and cement surface by Scanning Electron Microscope. Setting kinetics was evaluated using rheometry. ResultsElemental analysis revealed, for all cements, the presence of three major components: calcium, silicon and oxygen. Chlorine was detected in MM-MTA, MTA-Caps and Biodentine. Different radio-opacifiers were identified: bismuth oxide in ProRoot MTA, Angelus MTA and MM-MTA, zirconium oxide in Biodentine and calcium tungstate (CaWO4) in MTA-Caps. All cements were composed of di- and tri-calcium silicate, except Biodentine for which only the latter was detected. Major differences in setting kinetics were observed: a modulus of 8×108Pa is reached after 12min for Biodentine, 150min for MM-MTA, 230min for Angelus MTA and 320min for ProRoot MTA. The maximum modulus reached by MTA-Caps was 7×108Pa after 150min. SignificanceEven if these cements possess some common compounds, major differences in their composition were observed between them, which directly influence their setting kinetics.

Dentinogenic Responses after Direct Pulp Capping of Miniature Swine Teeth with Biodentine

IntroductionThe aim of this study was to evaluate pulpal responses after experimental direct pulp capping of mechanically exposed teeth with a new calcium silicate–based dentin replacement material. MethodsThirty-four anterior and posterior teeth of 3 miniature swine were used. Class V or I cavities were prepared on the buccal or occlusal surfaces, respectively. Pulpal exposures were further performed using a round carbide bur 0.8 mm in diameter. Exposures were treated with white MTA Angelus (Angelus, Londrina, PR, Brazil) or Biodentine (Septodont, Saint Maur des Fosses, France), and the cavities were further restored with Biodentine. The pulpal tissue responses were histologically assessed at postoperative periods of 3 and 8 weeks. Data were statistically analyzed using the Kruskal Wallis and the Mann-Whitney U tests. ResultsInflammatory infiltration or pulp tissue necrosis was not found in any of the specimens. All teeth showed mineralized matrix formation in the form of a complete hard tissue bridge composed of osteodentin or osteodentin followed by a discontinuous or continuous reparative dentin zone. A significantly higher thickness of the hard tissue bridge was found in the group of teeth treated with Biodentine at both 3 and 8 weeks. A number of teeth, which were under root development at the onset of the experimental procedures, exhibited ectopic pulp calcification. ConclusionsThe application of both calcium silicate–based materials in direct contact with the mechanically exposed pulp of healthy miniature swine teeth led to pulp repair with complete hard tissue bridge formation. The thickness of hard tissue bridges was significantly higher after pulp capping with Biodentine.

Cytotoxic effects of various mineral trioxide aggregate formulations, calcium-enriched mixture and a new cement on human pulp stem cells.

This in vitro study compared the cytotoxic effects of three commercially available MTA formulations naming ProRoot MTA (PMTA), Angelus MTA (AMTA), and Root MTA (RMTA), with calcium-enriched mixture (CEM) cement and a new nanohybrid MTA (NMTA) on human dental pulp stem cells (DPSC). Four disc-shaped specimens of each material were prepared. After completion of setting, 2 different (neat and 1/2) elutes of the test materials were made. Then in each cavity of a 96-well plate, 3000 cells were seeded and incubated in a humidified incubator with 5% CO2 and 95% air at 37(°)C for 24 h. After this period, the culture medium of each well was replaced with 200 μL of test material elutes. Plain culture medium was used as the negative control and distilled water as the positive control group. Cell viability was assessed using 2, 5-diphenyl-SH-tetrazelium bromide colorimetric assay, aka Mosmann's tetrazolium toxicity (MTT) assay, at three time intervals (24, 48, and 72 h after mixing). Data were analyzed using the ANOVA and Tukey's post hoc test (P=0.05). After 24 h, the viability of cells in neat concentration had no significant differences (P>0.05) except for the NMTA. However, CEM and AMTA, at 1/2 concentration exerted significant proliferative effects on cells. At 48 and 72-h intervals, significant proliferation of DPSCs was seen in all samples, except for the NMTA which exerted toxic effects on cells. All of the three commercial MTAs and CEM cement showed comparative biocompatibility. However, NMTA had cytotoxic effects on DPSCs at all the time intervals.

Investigation of a novel mechanically mixed mineral trioxide aggregate (MM-MTA(™) ).

To characterize a novel mechanically mixed mineral trioxide aggregate product (MM-MTA, MicroMega, Besançon, France) and to investigate the physical and chemical properties in comparison with ProRoot MTA (Dentsply, Tulsa Dental, Johnson City, TN, USA) and MTA Angelus (Angelus, Londrina, Brazil). The three materials were mixed according to manufacturer's instructions. Specimens 10mm in diameter and 2mm high were prepared and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis after 1-day and 28-day storage in physiological solution. Calcium ion leaching in solution and pH of the elution were also assessed. Furthermore, the setting time, radiopacity and material porosity were investigated. Statistical analysis was performed by anova and Tukey's post hoc tests. All the MTAs tested were composed primarily of tricalcium silicate and bismuth oxide. In addition, MM-MTA exhibited additional peaks for chlorine evident in the EDS analysis; calcium carbonate was present in the set material detected by XRD. Calcium hydroxide was present in the set ProRoot MTA and MTA Angelus. Calcium ion leaching and alkalization of the storage solution were demonstrated in all the materials. Both MM-MTA and MTA Angelus had a shorter setting time when compared to ProRoot MTA (P<0.001). ProRoot MTA exhibited larger pores and more porosity than MTA Angelus and MM-MTA. All the materials exhibited radiopacity greater than the 3mm aluminium thickness specified in ISO 6876 (2012). MM-MTA, ProRoot MTA and MTA Angelus are composed of Portland cement and bismuth oxide. In addition, MM-MTA contains calcium carbonate and a chloride accelerator. These additives affect the material hydration and the properties of the set material. The properties of MM-MTA are a result of a combination of factors, namely the particular cement mineralogy, radiopacifier loading, effective water-cement ratio and mechanical mixing.

Ex-vivo Sealing Ability of Different Thicknesses of White and Gray Angelus MTA as an Intra-orifice Barrier in Endodontically Treated Teeth

Ex-vivo Sealing Ability of Different Thicknesses of White and Gray Angelus MTA as an Intra-orifice Barrier in Endodontically Treated Teeth

Influence of diabetes mellitus on tissue response to MTA and its ability to stimulate mineralization.

To evaluate the influence of diabetes mellitus on the tissue response to mineral trioxide aggregate (MTA) and its ability to stimulate mineralization. Twenty-four male Wistar rats were divided into a non-diabetic control group and another with Alloxan-induced diabetes. Two polyethylene tubes, one kept empty as a control and the other containing Angelus MTA(®) , were implanted into the dorsal connective tissue of all rats for 30 days. Animals in each group received injections of calcein, alizarin, and oxytetracycline on day 7, 14, and 21, respectively. Animals were killed after 30 days; specimens were prepared by staining with hematoxylin and eosin (HE) and von Kossa technique as well as for examination of unstained sections with polarized light and fluorescence microscopy. The inflammatory reaction to the implanted tubes was equally mild in both groups. Structures staining with von Kossa were seen in response to Angelus MTA(®) , as were birefringent structures visualized on polarized light analysis; these had no relation to diabetic condition (P < 0.05). Fluorescence intensity was not changed in diabetic rats either (P < 0.05). Diabetes mellitus did not influence the tissue response to Angelus MTA(®) or the mineralization stimulated by it.

Development of MTA/HAp Biomaterials for Use in Endodontics

This work aims to conduct a study of development and characterization of a new endodontic biociment, the MTA/HAp. To this was used MTA Angelus®and a HAp synthesized in the laboratory in the proportions by weight 99% MTA/1% HAp (BIOC 1) and 95% MTA/5% HAp (BIOC 5), where the hydroxyapatite was added in order to introduce MTA to the characteristic of osteoconduction. The tests for the characterization of new cement were: X-ray diffraction, scanning electron microscopy and radiographic appearance. The results showed that the new developed biociments were obtained efficiently, since they showed the same crystalline phases of its starting materials (mineral trioxide aggregate and hydroxyapatite), with a morphology consisting of agglomerates of homogeneous distribution of irregular size and shape particles pre-sintered spherical and radiopacity feasible to be used in endodontics.Keywords:biomaterial,sealer,mineraltrioxideaggregate,hydroxyapatite.

Characterization of un-hydrated and hydrated BioAggregate™ and MTA Angelus™.

BioAggregate™ is a novel material introduced for use as a root-end filling material. It is tricalcium silicate-based, free of aluminium and uses tantalum oxide as radiopacifier. BioAggregate contains additives to enhance the material performance. The purpose of this research was to characterize the un-hydrated and hydrated forms of BioAggregate using a combination of techniques, verify whether the additives if present affect the properties of the set material and compare these properties to those of MTA Angelus™. Un-hydrated and hydrated BioAggregate and MTA Angelus were assessed. Un-hydrated cement was tested for chemical composition, specific surface area, mineralogy and kinetics of hydration. The set material was investigated for mineralogy, microstructure and bioactivity. Scanning electron microscopy, X-ray energy dispersive spectroscopic analysis, X-ray fluorescence spectroscopy, X-ray diffraction and isothermal calorimetry were employed. The specific surface area was investigated using a gas adsorption method with nitrogen as the probe. BioAggregate was composed of tricalcium silicate, tantalum oxide, calcium phosphate and silicon dioxide and was free of aluminium. On hydration, the tricalcium silicate produced calcium silicate hydrate and calcium hydroxide. The former was deposited around the cement grains, while the latter reacted with the silicon dioxide to form additional calcium silicate hydrate. This resulted in reduction of calcium hydroxide in the aged cement. MTA Angelus reacted in a similar fashion; however, since it contained no additives, the calcium hydroxide was still present in the aged cement. Bioactivity was demonstrated by deposition of hydroxyapatite. BioAggregate exhibited a high specific surface area. Nevertheless, the reactivity determined by isothermal calorimetry appeared to be slow compared to MTA Angelus. The tantalum oxide as opposed to bismuth oxide was inert, and tantalum was not leached in solution. BioAggregate exhibited high calcium ion release early, which was maintained over the 28-day period as opposed to MTA Angelus, which demonstrated low early calcium ion release which increased as the material aged. The mineralogical composition of BioAggregate was different to MTA Angelus. As opposed to MTA Angelus, BioAggregate did not contain aluminium and contained additives such as calcium phosphate and silicon dioxide. As a consequence, BioAggregate reacted more slowly and formation of calcium hydroxide and leaching of calcium ions in solution were not evident as the material aged. The additives in BioAggregate modify the kinetics and the end products of hydration. Although newer generation tricalcium silicate-based materials contain similar constituents to MTA, they do not undergo the same setting reactions, and thus, their clinical performance will not be comparable to that of MTA.

Análise físico-química do MTA e do cimento Portland associado a quatro diferentes radiopacificadores

INTRODUÇÃO: O Mineral Trióxido Agregado (MTA) é composto por cimento Portland (CP) e um radiopacificador (óxido de bismuto).OBJETIVO: Avaliar tempo de presa, solubilidade, pH, liberação de íons Cálcio e radiopacidade do cimento Portland puro ou associado a quatro radiopacificadores (sulfato de bário, carbonato de bismuto, óxido de bismuto e iodofórmio), comparados ao MTA branco (Angelus, Londrina, Brasil).MATERIAL E MÉTODO: A proporção empregada CP/radiopacificador foi de 4:1 em peso, (80% de cimento Portland e 20% de radiopacificador). A especificação 57 da ADA foi usada para avaliação do tempo de presa. A solubilidade foi analisada segundo a especificação ISO 6876/2001. A avaliação do pH foi realizada com peagâmetro digital e a liberação de íons Ca++foi verificada por meio de espectrofotômetro de absorção atômica. A radiopacidade foi determinada em milímetros de alumínio (mm/Al). Os resultados foram submetidos aos testes de Análise de Variância e Tukey, nível de significância 5%.RESULTADO: O sulfato de bário não alterou o tempo de presa final do CP. Radiopacidade inferior ao mínimo recomendado pelas normas da ADA nº 57 e ISO 6876/2001 foi observada para CP e CP associado com sulfato de bário. O CP associado ao iodofórmio apresentou solubilidade acima dos 3% recomendados pela ISO 6876/2001. Todos os materiais proporcionaram alcalinização do meio e promoveram liberação de íons cálcio.CONCLUSÃO: Carbonato de bismuto ou óxido de bismuto proporcionaram tempo de presa inicial, solubilidade, pH, liberação de íons Cálcio e radiopacidade adequados quando associados ao CP.

Apical Sealing Ability of a Novel Material: Analysis by Fluid Filtration Technique

The aim of this study is to evaluate the sealing ability of Biodentine(TM), which is new calcium-silicate based dental cement and has endodontic indications similar to those of MTA. The study sample consists of 21extracted human mandibular anterior teeth. The teeth were submitted to root-end preparation and instrumented up to file #40 by step back technique and randomly divided into 3 study groups (n=7): White MTA Angelus(TM) (Angelus, Angelus Odontológica, Londrina, PR, Brazil), Biodentine(TM) (Septodont, SeptodontSpecialités, Saint-MaurdesFosses, France) and the controls. The length of dye penetration between the filling material and tooth structure was measured in millimetres, using a calibrated stereo microscope (Leica MZ75, Germany) at 20× magnification under the same conditions. One-way Analysis of Variance (ANOVA) was used to indicate differences between the experimental groups and the controls. In addition, Tukey Multiple Comparisons Test was used to indicate differences within each group. The results showed that none of the groups were completely sealed. The mean and standard deviation for dye penetration in Biodentine(TM) group was 0.63±0.20 and in MTA Angelus(TM) group, it was 0.26±0.25. Regarding the comparisons between each group, significant differences were not observed (P=0.0193). The comparison between materials only found a significant difference only between MTA Angelus(TM) and Biodentine(TM) (P<0.05). This study evaluated the possibility of Biodentine(TM)'s sealing ability and marginal adaptation, since no studies are available on Biodentine. However, further in vitro and in vivo investigations should be conducted to determine the suitability of Biodentine(TM) for clinical application.

Uso clínico del agregado de trióxido mineral (MTA) en el tratamiento de lesiones periapicales y perforaciones radiculares

El propósito de la presente investigación fue emplear el cemento MTA (agregado de trioxido mineral) en forma clínica para resolver complicaciones en el tratamiento de endodoncia como son las perforaciones radiculares a nivel de cámara pulpar, así como en la obturación retrograda de tratamientos de apicectomia. Se empleó el cemento MTA - Blanco, Angelus, (Industria de productos odontologicos Ltda. Londrina - PR – Brazil) que se caracterizó por tener un tiempo de endurecimiento inicial de 10 minutos y el tiempo de endurecimiento final de 15 minutos. La radiopacidad que mostró el material fue algo superior a la de la dentina y el tejido óseo, facilitando su visualización en las radiografías de control. Se hicieron controles clínicos y radiográficos a los casos tratados tanto en el postoperatorio inmediato como a los sesenta días. Los resultados muestran que hubo adaptación del cemento a las paredes de la cavidad retroapical y de los trayectos de perforación, produciéndose un sellado apical y marginal. Los elementos constituyentes del cemento: silicato tricálcico, aluminato tricálcico, silicato dicálcico, aluminato ferrico tetracálcico; permitieron una estimulación del proceso de cicatrización y reparación de los tejidos circundantes, que evolucionaron en forma favorable hasta el momento del último control realizado en esta investigación.