Antibacterial Activity of Root Repair Cements in Contact with Dentin-An Ex Vivo Study.

This study assessed the antibacterial characteristics of the dentin/material interface and dentin surfaces exposed to experimental hydraulic calcium silicate cement (HCSC) with or without bioactive glass (BG) replacement (20% or 40%) or mixed with a silver nanoparticle (SNP) solution (1 or 2 mg/mL), and Biodentine, TotalFill BC RRM putty and Intermediate Restorative Material (IRM). Human root dentin segments with test materials were assessed at 1 or 28 days. In one series, the specimens were split to expose the dentin and material surfaces. A 24 h direct contact test was conducted against three-day established Enterococcus faecalis and Pseudomonas aeruginosa monospecies biofilms. In another series, the dentin/material interface of intact specimens was exposed to biofilm membranes for 3 days and the antibacterial activity was assessed via confocal microscopy. The interface was additionally characterised. All one-day material and dentin surfaces were antibacterial. Dentin surfaces exposed to HCSC with 40% BG-replacement, Biodentine and IRM had decreased antibacterial properties compared to those of the other cements. The HCSC mixed with a 2 mg/mL SNP solution had the highest antimicrobial effect in the confocal assay. The interfacial characteristics of HCSCs were similar. The test materials conferred antibacterial activity onto the adjacent dentin. The BG reduced the antibacterial effect of dentin exposed to HCSC; a 2 mg/mL SNP solution increased the antibacterial potential for longer interaction periods (three-day exposure).

Preparation and properties of the fine ground strontium-based endodontic cements.

In this study, fine powders of tristrontium aluminate (S3A) and distrontium cerate (S2Ce) cement were prepared using a dry grinding process, and their mechanical and ion dissolution properties were estimated. Fine cements showed the particles about 10 µm in diameter or smaller with sharp particle size distribution curves. The setting reaction of the fine cements was rapid; therefore, a 0.1% w/v of citric acid solution was used as the retarder. The compressive strengths of the fine cements were improved compared to those of the coarse cements at both 1 and 28 days after mixing at a water/powder ratio (W/P) of 0.4. The dissolution of Sr and Al ions from fine S3A cement was enhanced. However, the relative flowability decreases with fine grinding. Further studies on flowability, handling property are required. Additionally, the biological effects of endodontic cement should be studied both in vitro and in vivo.

Bioactivity and biocompatibility of bioceramic sealers in endodontics: an integrative review

Introduction: Bioceramic sealers have been gaining prominence in endodontics, meaning a great advance for endodontic therapy, mainly due to their biocompatibility and bioactivity. Objectives: research and discuss the literature about the bioactivity and biocompatibility of bioceramic sealants. Materials and methods: An integrative review was performed. The systematic plan consisted of four steps. In the first stage, a bibliographic survey was carried out in the Capes Periódicos Portal database. The search criteria were articles published between 2017 and 2022, found in the "advanced search" mode, using cross-references with the following keywords: bioceramics sealers AND endodontology AND root canals AND endodontic sealer AND bioactivity AND biocompatibility. Only documents found and published in full were evaluated. In the second stage, the titles and abstracts of the articles were read. In the third stage, a selection was made of those containing 3 to 5 keywords and a wording equal to or close to the proposed keywords. The fourth step consisted of reading the texts in full, followed by checking for duplicity and building a table with the collected information. Results: In view of the research carried out, 23 articles were obtained in the first stage. After reading the titles and abstracts, 21 articles were obtained. After selecting those containing 3 to 5 keywords, 10 articles met the criteria. One article was deleted due to duplicates. 9 articles met the exclusion and inclusion criteria and were selected to be part of the integrative review. Discussion: The selected studies in this literature review showed that bioceramic endodontic sealants perform well in endodontic therapy. Conclusion: To advance in its clinical application, more in vivo and in vitro studies with precise methods are needed to obtain more reliable data about its properties.

Investigation of a Novel Injectable Chitosan Oligosaccharide-Bovine Hydroxyapatite Hybrid Dental Biocomposite for the Purposes of Conservative Pulp Therapy.

This study aimed to develop injectable chitosan oligosaccharide (COS) and bovine hydroxyapatite (BHA) hybrid biocomposites, and characterise their physiochemical properties for use as a dental pulp-capping material. The COS powder was prepared from chitosan through hydrolytic reactions and then dissolved in 0.2% acetic acid to create a solution. BHA was obtained from waste bovine bone and milled to form a powder. The BHA powder was incorporated with the COS solution at different proportions to create the COS-BHA hybrid biocomposite. Zirconium oxide (ZrO2) powder was included in the blend as a radiopacifier. The composite was characterised to evaluate its physiochemical properties, radiopacity, setting time, solubility, and pH. Fourier-transform infrared spectroscopic analysis of the COS-BHA biocomposite shows the characteristic peaks of COS and hydroxyapatite. Compositional analysis via ICP-MS and SEM-EDX shows the predominant elements present to be the constituents of COS, BHA, and ZrO2. The hybrid biocomposite demonstrated an average setting time of 1 h and 10 min and a pH value of 10. The biocomposite demonstrated solubility when placed in a physiological solution. Radiographically, the set hybrid biocomposite appears to be more radiopaque than the commercial mineral trioxide aggregate (MTA). The developed COS-BHA hybrid biocomposite demonstrated good potential as a pulp-capping agent exhibiting high pH, with a greater radiopacity and reduced setting time compared to MTA. Solubility of the biocomposite may be addressed in future studies with the incorporation of a cross-linking agent. However, further in vitro and in vivo studies are necessary to evaluate its clinical feasibility.

Physicochemical and biological properties of four calcium silicate-based endodontic cements.

Background/purpose: Several brands of calcium silicate-based cements (CSBCs) are currently marketed. Here we compared physicochemical and biological properties of new products Ortho MTA (BioMTA), Retro MTA (BioMTA), and EZ-Seal (Ezekiel) to widely used ProRoot MTA (Dentsply Tulsa). Materials and methods: CSBCs were analyzed by X-ray diffractometry and examined by scanning electron microscopy. Elemental composition was determined by energy dispersive spectroscopy. Particle size was measured by particle size analyzer. Human stem cells from apical papilla (SCAPs) were incubated with eluates from CSBCs. Survival of SCAP cells was evaluated with MTT assay. The Alizarin red S stain was used to identify calcified nodules formed in SCAP cultures. The effects of CSBC eluates on SCAP proliferation and migration were examined using an in-vitro scratch "wound-healing" assay. Results: All CSBC specimens showed similar X-ray diffraction patterns. The average particle size of EZ-Seal was smaller than ProRoot MTA, Ortho MTA, and Retro MTA (P < 0.001). The least cytotoxicity of eluates was found for EZ-Seal. In the Alizarin red S staining test, calcified nodules were observed in cultures with ProRoot MTA, Ortho MTA, and Retro MTA, however, no calcified nodules were observed in cultures with EZ-Seal. SCAP proliferation and migration capacity in presence of EZ-Seal was higher than with ProRoot MTA, Ortho MTA, and Retro MTA (P < 0.001). Conclusion: EZ-Seal has a smaller average particle size and a better cytocompatibility than all other examined CSBCs.

Sol-Gel Synthesis of Endodontic Cements: Post-Synthesis Treatment to Improve Setting Performance and Bioactivity.

The sol-gel process is a wet chemical technique that allows very fine control of the composition, microstructure, and final textural properties of materials, and has great potential for the synthesis of endodontic cements with improved properties. In this work, the influence of different sol-gel synthesis variables on the preparation of endodontic cement based on calcium silicate with Ca/Si stoichiometry equal to 3 was studied. Starting from the most optimal hydraulic composition selected, a novel second post-synthesis treatment using ethanol was essayed. The effects of the tested variables were analyzed by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption, and Gillmore needles to determine the setting time and simulated body fluid (SBF) immersion to measure the bioactive response in vitro. The results indicated that the sol-gel technique is effective in obtaining bioactive endodontic cements (BECs) with high content of the hydraulic compound tricalcium silicate (C3S) in its triclinic polymorph. The implementation of a novel post-synthesis treatment at room temperature using ethanol allows obtaining a final BEC product with a finer particle size and a higher CaCO3 content, which results in an improved material in terms of setting time and bioactive response.

Biocompatibility and pro-mineralization effect of tristrontium aluminate cement for endodontic use.

Background/purpose: Tristrontium aluminate (S3A) is a hydraulic cement with setting behavior similar to that of mineral trioxide aggregate (MTA). This study examined the biological effects of S3A on mouse dental papilla cells (MDPs) in vitro and on rat exposed pulps in vivo. Materials and methods: Extracts of S3A and MTA were prepared by immersing each cement in ultrapure water. MDPs were cultured with S3A or MTA extracts, and cell proliferation was evaluated with a tetrazolium-salt assay. Attachment of MDPs on the set cements was examined with scanning electron microscopy (SEM). mRNA expression of bone morphogenic protein (Bmp2), osteocalcin (Oc) and osteopontin (Opn) in MDPs exposed to S3A or MTA extracts was determined with reverse transcription-quantitative polymerase chain reaction. Mineralized nodule formation was evaluated with Alizarin Red S staining. Simulated body fluid (SBF)-dipped S3A was examined with SEM and energy dispersive X-ray analysis (EDX). Exposed molar pulps of male Wistar rats capped with S3A or MTA were histologically examined. Results: S3A extract did not inhibit proliferation of MDPs. Set S3A and MTA exhibited attachment of MDPs on their surface. S3A extract showed significantly higher mineralized nodule formation and mRNA expression of Bmp2, Oc, and Opn than did MTA extract. SBF-dipped S3A exhibited formation of surface precipitates, which were composed of Ca, P, Sr, and Al. Direct pulp capping with S3A and with MTA induced mineralized tissue repair of the exposed pulp. Conclusion: S3A possesses biocompatibility and pro-mineralization effects comparable to those of MTA.

Physicochemical and Biological Properties of Mg-Doped Calcium Silicate Endodontic Cement.

Calcium silicate-based cement has been widely used for endodontic repair. However, it has a long setting time and needs to shorten setting time. This study investigated the effects of magnesium (Mg) ion on the setting reaction, mechanical properties, and biological properties of calcium silicate cement (CSC). Sol-gel route was used to synthesize Mg ion-doped calcium silicate cement. Synthesized cement was formulated with the addition of different contents of Mg ion, according to 0, 1, 3, 5 mol% of Mg ion-doped calcium silicate. The synthesized cements were characterized with X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). We also evaluated the physicochemical and biological properties of cement, such as the setting time, compressive strength, micro-hardness, simulated body fluid (SBF) immersion, cytotoxicity, and cell differentiation tests. As a result, the Mg ion improves the hydration properties of calcium silicate cement, and the setting time is reduced by increasing the amounts of Mg ion. However, the mechanical properties deteriorated with increasing Mg ion, and 1 and 3 mol% Mg-doped calcium silicate had appropriate mechanical properties. Also, the results of biological properties such as cytotoxicity, ALP activity, and ARS staining improved with Mg ion. Consequently, the optimal condition is 3 mol% of Mg ion-doped calcium silicate (3%Mg-CSC).

Distrontium Cerate as a Radiopaque Component of Hydraulic Endodontic Cement.

This study aimed to synthesize distrontium cerate (2SrO·CeO2: S2Ce) and evaluate its properties as an alternative component of the endodontic cement. S2Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase was confirmed using X-ray diffraction. S2Ce cement exhibited a rapid setting time (121 min) and achieved a high compressive strength (72.1 MPa) at 1 d after mixing, comparable to the compressive strength of a commercial mineral trioxide aggregate (MTA) cement (ProRoot MTA) after 28 d post mixing. However, the compressive strength decreased after 28 d of storage when the W/P ratio was 0.30-0.40 (p < 0.05). Ion dissolution test of the S2Ce cement showed that strontium ions were released after immersion in water (5.27 mg/mL after 1 d), whereas cerium dissolution was not detected. S2Ce exhibited approximately three times higher radiopacity (9.0 mm aluminum thickness equivalent) compared to the commercial MTA (p < 0.05). These findings suggest that S2Ce is a possible component for hydraulic endodontic cement that demonstrates a rapid setting and high radiopacity.

Evaluation with Micro-CT of the Canal Seal Made with Two Different Bioceramic Cements: GuttaFlow Bioseal and BioRoot RCS.

AIM: The aim of this work is to investigate the quality of root canal seals obtained by comparing two bioceramic cements, GuttaFlow bioseal and BioRoot RCS, focusing on the presence of voids created during the canal obturation procedure. MATERIALS AND METHODS: The voids are analyzed using a micro-computed tomography (micro-CT) device. The study will be performed using images of the endodontic space before and after filling of a selected group of elements. Furthermore, the average thickness of the cement, the average quantity of gutta-percha compared to the total shaped volume, and the average quantity of the two cements, GuttaFlow bioseal and BioRoot RCS, with respect to the total shaped volume were considered. The apical, middle, and coronal thirds have been investigated in a sectorial manner. Images have been analyzed using a CT-An™ software and visualized through a three-dimensional (3D) reconstruction of the slices by the software CT-Vol™. Shapiro-Wilk test/Test D'Agostino-Pearson/Kolmogorov-Smirnov test were used to ensure the reliability of results. RESULTS: No significant differences were observed in the amount of gutta-percha compared to the shaped volume between the GuttaFlow bioseal group and BioRoot RCS. No statistically significant difference was observed between the two groups in terms of voids. CONCLUSION: The data obtained from this study allowed to conclude that the samples filled with GuttaFlow bioseal and BioRoot RCS have a similar seal capacity since no statistically significant differences were observed between the two groups. No sample showed the absence of voids within the root canal obturation. CLINICAL SIGNIFICANCE: Even if the two cements tested showed differences in terms of void volume and ability to fill thin spaces, they should be considered both acceptable and equivalent in terms of clinical sealing ability.

A Microstructure Insight of MTA Repair HP of Rapid Setting Capacity and Bioactive Response.

Mineral trioxide aggregate (MTA) is considered a bioactive endodontic material, which promotes natural mineralization at the material-tooth tissue interface. MTA Repair HP stands out because of the short setting time and the quick and effective bioactive response in vitro. The bioactivity, depens on material composition and microstructure. This work is devoted to analyze MTA Repair HP microstructural features, of both the powder precursor and set material, to get insights into the material physicochemical parameters-functionality performance relationships. Transmission electron microscopy (TEM), and field emission gun scanning electron microscopy (FEG-SEM) coupled with energy-dispersive X-ray (EDX) analyses were performed. X-ray diffraction (XRD) measurements were carried out at different times to investigate setting process. Bioactivity evaluation in vitro was carried out by soaking the processed cement disk in simulated body fluid (SBF). The presented results point out those MTA Repair HP precursor material characteristics of tricalcium silicate particles of nanometric size and high aspect ratio, which provide an elevated surface area and maximized components dispersion of calcium silicate and very reactive calcium aluminate. The MTA Repair HP precursor powder nanostructure and formulation, allows a hydration process comprising silicate hydrate structures, which are very effective to achieve both fast setting and efficient bioactive response.

Avaliação de propriedades físico-químicas, tempo de endurecimento e drenagem de um cimento endodôntico adicionado ao MTA em diferentes proporções / Evaluation of physico-chemical properties, time of hardening and draining of an endodontic sealer added to mta in different proportions

Objetivo: o objetivo desta pesquisa foi avaliar o tempo e o fluxo de endurecimento do cimento AH-PLUS e MTA nas proporções de 10%, 20% e 30%, a fim de adicionar a capacidade de estimular a deposição de tecido duro. Material e Métodos: Para o teste de fluxo, 0,5 ml de cimento foram depositados em uma placa de vidro e outra placa foi adicionada com uma carga adicional, após 10 minutos a carga foi removida e o diâmetro do círculo formado pelo cimento foi medido com um Bússola digital. Para o tempo de endurecimento, foram utilizados moldes cilíndricos preenchidos com o cimento testado, mantidos dentro de um forno e os testes de agulha de Gillmore foram realizados no material em intervalos de 60 segundos até que as marcas não fossem visíveis na superfície do cimento testado. Resultados: Na vazão, os valores obtidos foram: 41,1 mm (10% MTA), 32,86 mm (20% MTA), 21,91 mm (30% MTA), 24,41 mm AHPlus® e 26,47 mm MTA Fillapex®. O tempo de endurecimento encontrado nesta pesquisa foi de 1631 'em proporção (10% MTA), 628,4 em proporção (20% MTA), 567' em proporção (30% MTA), 767 em AH Plus e Fillapex MTA não. presou dentro de 6 semanas. Conclusão: concluiu-se que a adição de 10%, 20% e 30% de MTA ao AH Plus não alterou as propriedades do fluxo e o tempo estabelecido

Objective: evaluate the hardening time and flow of AH-PLUS and MTA cement in the proportions of 10%, 20% and 30% in order to add the ability to stimulate the deposition of hard tissue. Material and Methods: For the flow test, 0.5 ml of cement was deposited on a glass plate and another plate was added with an additional charge, after 10 minutes the charge was removed and the diameter of the circle formed by the cement was measured with a digital compass. For the hardening time, cylindrical molds filled with the tested cement were used, kept inside a kiln and Gillmore needle tests were performed on the material at 60 second intervals until the marks were not visible on the surface of the tested cement. Results: In the flow rate, the values obtained were: 41.1mm (10% MTA), 32.86mm (20% MTA), 21.91mm (30% MTA), 24.41mm AHPlus® and 26.47mm MTA Fillapex®. The hardening time found in this survey was 1631 'in proportion (10% MTA), 628.4 in proportion (20% MTA), 567' in proportion (30% MTA), 767 in AH Plus and Fillapex MTA did not. took prey within 6 weeks. Conclusion: it was concluded that the addition of 10%, 20% and 30% of MTA to AH Plus did not change the flow properties and the established time

Antibacterial effect of four endodontic cements against enterococcus faecalis ATCC 29212: an in vitro study

Objective: to compare the in vitro antibacterial effect of the root canal cements Endobalsam, Top Seal, Apexit and Endofill against enterococcus faecalis ATCC 29212. Materials and method: Eighty-five applications of cements on enterococcus faecalis, cultured in vitro on solid media in Petri dishes, were analyzed. five groups were evaluated: four for each cement, and the fifth for the positive control (amoxicillin). the antibacterial effect was measured by the diameters of the bacterial inhibition halos at 24 hours, 48 hours, and seven days. student´s t-test, ANOVA and the Tukey test were used for the statistical analysis. results: no statistically significant differences were found at 24 hours (p>0.05); at 48 hours and seven days, Endofill and Apexit had the greatest effect (p<0.05); finally, on day 7 only Endofill showed an effect similar to the positive control (p>0.05). conclusion: enterococcus faecalis ATCC 29212 was susceptible to all cements. Endofill had greater in vitro antibacterial effect than Apexit, Top Seal and Endobalsam.

Estudo comparativo da radiopacidade de cimentos endodônticos avaliado por meio de sistema radiográfico digital / Evaluation of the radiopacity of endodontic cements using digital radiograph system: comparative study

A radiopacidade e especificação foram avaliadas de acordo com a norma padrão ISO6876/2001. Para a análise da radiopacidade, 10 placas acrílicas foram confeccionadas com seis furos, cada um com 10,0 mm de diâmetro e 2,0 mm de espessura, e preenchidos com cinco cimentos estudados: AH Plus, Endofill, EndoREZ, Sealapex e MTA Fillapex, e como controle foi utilizada guta-percha. Imagens radiográficas digitais dos espécimes foram importadas do software Digora 1.51. Um densitômetro de alumínio foi utilizado como um instrumento de medição da densidade radiográfica na comparação das amostras, e o valor da radiopacidade foi determinado de acordo com essa densidade radiográfica (mmAl). Os resultados foram analisados estatisticamente por Kruskal-Wallis e complementados por StudentNewman-Keuls. Os cimentos testados apresentaram diferenças estatisticamente significativas entre eles (p<0,05). Os valores da radiopacidade dos cimentos em ordem decrescente em escala de alumínio foram os seguintes: AH Plus (14.86), Sealapex (13.50), Endofill (12.87), MTA Fillapex (11.90) e EndoREZ (10.27). Concluiu-se que a maior radiopacidade ocorreu no cimento AH Plus, porém, todos os materiais testados preencheram os requisitos das normas ISO 6876/2001 (AU).

Specification and radiopacity were evaluated according to standard ISO 6876/2001. For the analysis of radiopacity, 10 acrylic plates were made with six holes, each with 10.0 mm diameter and 2.0 mm thick, and filled with the five studied cements: AH Plus, Endofill, EndoREZ, Sealapex, MTAFillapex, and a control guta-percha was used. Digital radiographic images of the specimens were imported from Digora software version 1.51. An aluminum densitometer was used as an instrument for measure the radiographic density in the comparison sample, and the value of optical density was determined in accordance with this radiographic density (mm Al). The results were statistically analyzed using Kruskal-Wallis test and complemented by Student-Newman-Keuls test. The tested cements showed significant statistically differences between them (p < 0.05). The values of the radiopacity of the cement in decreasing scale aluminum were the following: AH Plus (14.86), Sealapex (13.50), Endofill (12.87), MTA Fillapex (11.90), and EndoREZ (10.27). It was concluded that most radiopacity occurred in AH Plus cement, however, all materials tested met the requirements of ISO 6876/2001 standards (AU).

Adhesion and formation of tags from MTA Fillapex compared with AH Plus® cement

Introduction and Objective: The aim of this study was two-fold: 1) to evaluate, in vitro, the shear bond strength of two sealers by push-out test and 2) to assess the failures after displacement. Additionally, the formation of tags was observed by SEM. Material and methods: Forty mandibular premolars were selected and the canals were subjected to biomechanical preparation with rotary instruments. These specimens were divided into two groups according to the sealer (n = 20): GI - MTA Fillapex and GII - AH Plus. All roots were filled with sealer only, without gutta-percha. After a period corresponding to three times the setting time of the sealer, the roots were sectioned transversely into slices of 1 mm thickness, to obtain one slice from the cervical third, to be used in the push-out test. Following, two slices of each group were randomly chosen for ultrastructural analysis by scanning electron microscopy (SEM). The data obtained in shear bond strength test were subjected to statistical analysis. Results: AH Plus cement exhibited higher shear bond strength values (1.332±0.75 MPa) than MTA Fillapex (0.071±0.07 MPa), with statistically significant differences. Conclusion: MTA Fillapex has a low bond strength with less formation of tags than AH Plus.

Can the Cure Time of Endodontic Sealers Affect Bond Strength to Root Dentin?

The cure time of endodontic sealers may influence the bond strength of fiber posts to root dentin. Forty teeth were selected and endodontically filled using calcium hydroxide cement and then divided into 2 groups according to the time elapsed between endodontic filling and post luting (n = 20): Immediately - glass fiber post luting immediately after endodontic filling; and Delayed - post luting performed 7 days after endodontic filling. The roots were also subdivided according to resin cement used for post luting (RelyX ARC and RelyX Unicem). The specimens were stored at 37°C for 24 h and sectioned in six 1-mm-thick slices from cervical, middle and apical thirds. The slice specimens were submitted to a push-out test at a crosshead speed of 0.5 mm/min, and the bond strength values obtained (MPa) were submitted to two-way ANOVA in a split-plot arrangement and Tukey's test (α=0.05). For both RelyX ARC and Unicem, the bond strength was significantly higher when the posts were cemented 7 days after the endodontic treatment. RelyX Unicem showed significantly higher bond strength values than RelyX ARC for both cementation periods. It was concluded that post luting should be made after the complete setting of the root canal sealer. Self-adhesive resin cement should be preferred for fiber post luting.

O tempo de presa de cimentos endodônticos pode afetar a resistência de união de pinos de fibra de vidro à dentina radicular. Quarenta dentes foram selecionados e tratados endodonticamente com cimento à base de hidróxido de cálcio. Em seguida, os mesmos foram divididos em dois grupos de acordo com o tempo decorrido entre o tratamento endodôntico e a cimentação definitiva (n=20): Imediato - pinos de fibra de vidro cimentados após o tratamento endodôntico; e Mediato - cimentação do pino realizada 7 dias após o tratamento endodôntico. As raízes foram subdivididas de acordo com o cimento resinoso (RelyX ARC e RelyX Unicem). As amostras foram armazenadas a 37 °C durante 24 h e seccionadas em seis fatias de 1 mm de espessura relacionadas com terços cervical, médio e apical. Os espécimes foram submetidos a teste de push-out a uma velocidade de 0,5 mm/min e os valores de resistência de união obtidos (MPa) foram submetidos à análise de variância em esquema de parcelas subdivididas e teste de Tukey (α=0,05). Para os cimentos RelyX ARC e Unicem, a resistência de união foi maior quando os pinos foram cimentados 7 dias após o tratamento endodôntico. RelyX Unicem apresentou valores de resistência de união superiores ao RelyX ARC para os períodos de cimentação. Concluiu-se que a cimentação do pino de fibra de vidro deve ser feita após o completo tempo de presa do cimento endodôntico. Cimentos resinosos auto-adesivos devem ser preferidos para cimentação de pinos de fibra.

Subcutaneous connective tissue reactions to various endodontic biomaterials: an animal study.

BACKGROUND AND AIMS: Biocompatibility of root-end filling materials is a matter of debate. The aim of this study was to compare the biocompatibility of a variety of commercial ProRoot WMTA cements and a resin-based cement (Geristore®) with different pH values of setting reaction and different aluminum contents, implanted into the subcutaneous connective tissue of rats at various time intervals. MATERIALS AND METHODS: Fifty Sprague-Dawley rats were used in this study. Polyethylene tubes were filled with Angelus WMTA, ProRoot WMTA, Bioaggregate, and Geristore. Empty control tubes were implanted into subcutaneous tissues and harvested at 7-, 14-, 28- and 60-day intervals. Tissue sections of 5 µm were stained with hematoxylin and eosin and observed under a light microscope. Inflammatory reactions were categorized as 0, none (without inflammatory cells); 1, mild (inflammatory cells ≤25); 2, moderate (25-125 inflammatory cells); and 3, severe (>125 inflammatory cells). Statistical analysis was performed with Kruskal-Wallis and Mann Whitney U tests. RESULTS: ProRoot WMTA and Angelus elicited significantly less inflammation than other materials (P<0.05). After 7 days, however, all the materials induced significantly more inflammation than the controls (P<0.05). Angelus-MTA group exhi-bited no significant differences from the Bioaggregate group (P=0.15); however, ProRoot WMTA elicited significantly less inflammation than Bioaggregate (P=0.02). Geristore induced significantly more inflammation than other groups (P<0.05). CONCLUSION: Geristore induced an inflammatory response higher than ProRoot WMTA; therefore, it is not recommended for clinical use.

Biocompatibility of mineral trioxide aggregate and three new endodontic cements: An animal study.

BACKGROUND: Introducing new endodontic cements should await comprehensive investigations and new formulations have to be tested in vivo before applying in human beings. So, the purpose of this study was to compare the biocompatibility of new endodontic cements, calcium aluminate α-aluminate cement (CAAC), calcium aluminate α-aluminate plus cement (CAAC plus), and a mixture of wollastonite and CAAC cement (WOLCA) and mineral trioxide aggregate (MTA), in subcutaneous connective tissue of rats. MATERIALS AND METHODS: Twenty-seven Wistar rats were divided into three groups of 7, 14, and 30 experimental days. Sterile polyethylene tubes were filled with MTA, CAAC, CAAC Plus, and WOLCA cement and implanted subcutaneously. Empty tubes were implanted as negative control. After the experimental periods, animals were sacrificed by anesthetic overdosing. The occurrence of inflammatory responses was scored according to the previously established scores. Data were statistically analyzed using Friedman, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests. The level of significance was 5% (P<0.05). RESULTS: There was a statistically significant difference between experimental and negative control sites in each group (P<0.05). CAAC Plus showed the highest mean scores of inflammation, compared with MTA, CAAC, and WOLCA cement sits at the end of all periods (P<0.05). There were no statistically significant differences between inflammatory scores of each site in different experimental groups, except CAAC plus sites, in which inflammation increased significantly with time (P<0.05). CONCLUSION: According to the results of the current study, biocompatibility of CAAC and WOLCA cement were comparable with that of MTA, but CAAC Plus induced an inflammatory response higher than MTA, therefore is not biocompatible.

Effect of previous calcium hydroxide dressing on the sealing properties of the new endodontic cement apical barrier.

OBJECTIVES: Using the fluid filtration method, an in vitro study was conducted to evaluate the effects of medication with calcium hydroxide on the sealing ability of the New Endodontic Cement (NEC) apical barrier in the short and long terms. METHODS: Fifty extracted single rooted teeth were prepared and apical resorption produced using acid sulfuric for four days. The teeth were randomly divided into two experimental groups (n=20) and two control groups. In group 1, calcium hydroxide was placed into all canals for one week and in group 2, no medication was used. In both groups, a 4 mm NEC apical plug was placed in the canals and the remaining portion of the canals was filled with gutta-percha. The amount of microleakage of all samples was evaluated after one week and three months. The data were statistically analyzed using two-way ANOVA. RESULTS: There was no significant difference between the two groups in either time period (P>.05). In both group 1 and group 2, microleakage increased after three months but this increase was not statistically significant (P>.05). CONCLUSIONS: According to the result of this study, medication with calcium hydroxide had no adverse effect on the short- and long-term sealing properties of an NEC apical plug.

Calcium-enriched mixture pulpotomy of a human permanent molar with irreversible pulpitis and condensing apical periodontitis.

This case report describes a pulpotomy treatment of a permanent mature molar tooth with established irreversible pulpitis and condensing apical periodontitis, using calcium-enriched mixture (CEM) cement. Clinical examination revealed that the first right lower molar had a large carious lesion with history of spontaneous/lingering pain; radiographic examination showed condensing apical periodontitis. Pulpotomy was opted as the treatment; cervical pulpotomy was carried out. Following hemostasis, the radicular pulp stumps were covered with ~2-mm-thick layer of the prepared CEM cement; the tooth was restored with amalgam. Two-year follow-up showed that the treated tooth had been symptomless, and there were no clinical signs/symptoms of either inflammation or infection. Radiographically, the periradicular lesion was completely healed with reconstruction of bone structures to normal appearance; the root canals were not calcified. According to chemical, physical, and biological properties of the CEM cement, this novel biomaterial may be suitable for endodontic treatment.