Publications by authors named "Roberta Bosso-Martelo"

18 Publications

  • Page 1 of 1

Physicochemical, biological, and antibacterial evaluation of tricalcium silicate-based reparative cements with different radiopacifiers.

Dent Mater 2021 02 13;37(2):311-320. Epub 2020 Dec 13.

Department of Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araraquara, SP, Brazil. Electronic address:

Objective: To evaluate tricalcium silicate-based (TCS) experimental materials, associated with zirconium oxide (ZrO), calcium tungstate (CaWO) or niobium oxide (NbO) radiopacifiers, in comparison with MTA Repair HP (Angelus).

Methods: Physicochemical tests: setting time, radiopacity, pH and solubility. In vitro assays: cytotoxicity: MTT and Neutral Red - NR; cell bioactivity: alkaline phosphatase activity (ALP), Alzarin red staining (ARS) and real time PCR (qPCR). Antibacterial activity: direct contact on Enterococcus faecalis in the planktonic form. Physicochemical and ARS data were submitted to ANOVA/Tukey tests; antibacterial activity, to Kruskall-Wallis and Dunn tests; MTT, NR, ALP and qPCR were analyzed by ANOVA/Bonferroni tests (α = 0.05).

Results: TCS + CaWO presented the longest setting time and MTA HP the shortest. Except for TCS, all the materials presented radiopacity above 3 mmAl. The cements had alkaline pH, antibacterial activity, low solubility and no cytotoxic effects. The highest ALP activity occurred in 14 days, especially to TCS, TCS + ZrO and TCS + CaWO. TCS + ZrO, TCS + NbO and MTAHP had higher mineralized nodule formation than those of the negative control (NC). After 7 days, there was no difference in mRNA expression for ALP, when compared to NC. However, after 14 days there was no overexpressed ALP mRNA, especially TCS + NbO, in relation to the CN. All the materials presented antimicrobial action.

Significance: The pure tricalcium silicate associated with ZrO, CaWO or NbO had appropriate physicochemical properties, antibacterial activity, cytocompatibility and induced mineralization in Saos-2, indicating their use as reparative materials.
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http://dx.doi.org/10.1016/j.dental.2020.11.014DOI Listing
February 2021

Development and evaluation of reparative tricalcium silicate-ZrO -Biosilicate composites.

J Biomed Mater Res B Appl Biomater 2021 Apr 28;109(4):468-476. Epub 2020 Aug 28.

Department of Restorative Dentistry, School of Dentistry, São Paulo State University (UNESP), Araraquara, Sao Paulo, Brazil.

Biosilicate is a bioactive glass-ceramic used in medical and dental applications. This study evaluated novel reparative materials composed of pure tricalcium silicate (TCS), 30% zirconium oxide (ZrO ) and 10 or 20% biosilicate, in comparison with Biodentine. Setting time was evaluated based on ISO 6876 standard, radiopacity by radiographic analysis, solubility by mass loss, and pH by using a pH meter. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and NR assays. Alkaline phosphatase (ALP) activity and alizarin red were used to evaluate cell bioactivity. Antimicrobial activity was assessed on Enterococcus faecalis by the direct contact test. The data were submitted to analysis of variance (ANOVA)/Tukey; Bonferroni and Kruskal-Wallis, and Dunn tests (α = 0.05). The association of Biosilicate with TCS + ZrO had appropriate setting time, radiopacity, and solubility, alkaline pH, and antimicrobial activity. TCS and Biodentine showed higher ALP activity in 14 days than the control (serum-free medium). All cements produced mineralized nodules. In conclusion, Biosilicate + TCS ZrO decreased the setting time and increased the radiopacity in comparison to TCS. Biosilicate + TCS ZrO2 presented lower solubility and higher radiopacity than Biodentine. In addition, these experimental cements promoted antimicrobial activity and mineralization nodules formation, suggesting their potential for clinical use.
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http://dx.doi.org/10.1002/jbm.b.34714DOI Listing
April 2021

Evaluation of Physicochemical Properties of a New Calcium Silicate-based Sealer, Bio-C Sealer.

J Endod 2019 Oct 22;45(10):1248-1252. Epub 2019 Aug 22.

Department of Restorative Dentistry, São Paulo State University, School of Dentistry, Araraquara, São Paulo, Brazil.

Introduction: Calcium silicate-based materials have been proposed as root canal sealers for root canal treatment. The aim of this study was to evaluate the physicochemical properties of a new calcium silicate-based sealer (Bio-C Sealer; Angelus, PR, Brazil) compared with a calcium silicate endodontic sealer (TotalFill BC Sealer; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) and an epoxy resin sealer (AH Plus; Dentsply DeTrey, Konstanz, Germany).

Methods: The setting time and flow were evaluated based on ISO 6876 standard. The pH value was evaluated after different time intervals of storage in deionized water (1, 7, 14, and 21 days). Radiopacity was evaluated by radiographic analysis in millimeters of aluminum. Solubility and volumetric change were evaluated after 30 days of immersion in distilled water. Solubility was assessed by mass loss (%), and volumetric change was evaluated by micro-computed tomographic imaging. The data were submitted to analysis of variance and Tukey statistical tests (P < .05).

Results: TotalFill BC Sealer and Bio-C Sealer were similar regarding radiopacity, volumetric change, and pH values (P > .05). Bio-C Sealer presented the shortest setting time and the highest flow and solubility (P < .05). AH Plus showed the highest radiopacity and the lowest flow, pH, solubility, and volumetric change (P < .05).

Conclusions: Bio-C Sealer showed a short setting time, alkalinization ability, and adequate flow and radiopacity as well as low volumetric change. However, this sealer had higher solubility than the rates required by ISO 6876 standard.
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http://dx.doi.org/10.1016/j.joen.2019.07.006DOI Listing
October 2019

Solubility, Porosity, Dimensional and Volumetric Change of Endodontic Sealers.

Braz Dent J 2019 Jul 22;30(4):368-373. Epub 2019 Jul 22.

Department of Restorative Dentistry, School of Dentistry, UNESP - Universidade Estadual Paulista, Araraquara, SP, Brazil.

The aim of this study was to evaluate physical properties of endodontic sealers (AH Plus, MTA Fillapex and Endofill), by conventional and micro-CT tests. Dimensional stability was evaluated after immersion of materials in distilled water for 30 days. Solubility and volumetric change were evaluated after 7 and 30 days of immersion in distilled water. Solubility was evaluated by means of mass loss and volumetric change was assessed by micro-CT. Porosity was evaluated under a microscope after 7 days of immersion in distilled water, and by using micro-CT after setting and immersion in distilled water for 7 and 30 days. Statistical analysis was performed by ANOVA and Tukey's test with 5% significance level. MTA Fillapex presented the highest solubility (p<0.05), showing values above the ISO/ADA recommendations. MTA Fillapex presented higher volumetric and dimensional changes, followed by Endofill and AH Plus (p<0.05). Dimensional stability of the MTA Fillapex and AH Plus did not follow ISO/ADA standards. The highest total porosity was observed for MTA Fillapex (p<0.05). Endofill had higher total porosity than AH Plus according to microscope evaluation (p<0,05), and both sealers were similar in micro-CT assessment (p>0,05). In conclusion, MTA Fillapex presented higher solubility, dimensional and volumetric change besides porosity compared to the other evaluated sealers. The assessed physical properties of sealers are related, and the different tests provided complementary data. Micro-CT is a valuable method for assessment of physical properties of endodontic materials.
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http://dx.doi.org/10.1590/0103-6440201902607DOI Listing
July 2019

Ytterbium Oxide as Radiopacifier of Calcium Silicate-Based Cements. Physicochemical and Biological Properties.

Braz Dent J 2018 Sep-Oct;29(5):452-458

Department of Restorative Dentistry, Araraquara Dental School, UNESP - Univ Estadual Paulista, Araraquara, SP, Brazil.

This study evaluated physicochemical properties, cytotoxicity and bioactivity of MTA Angelus (MTA), calcium silicate-based cement (CSC) and CSC with 30% Ytterbium oxide (CSC/Yb2O3). Setting time was evaluated using Gilmore needles. Compressive strength was evaluated in a mechanical machine. Radiopacity was evaluated using radiographs of materials and an aluminum scale. Solubility was evaluated after immersion in water. Cell viability was evaluated by means of MTT assay and neutral red staining, and the mineralization activity by using alkaline phosphatase activity and Alizarin Red staining. The data were submitted to ANOVA, Tukey and Bonferroni tests (5% significance). The bioactive potential was evaluated by scanning electron microscopy. The materials presented similar setting time. MTA showed the lowest compressive strength. MTA and CSC/Yb2O3 presented similar radiopacity. CSC/Yb2O3 showed low solubility. Saos-2 cell viability tests showed no cytotoxic effect, except to 1:1 dilution in NR assay which had lower cell viability when compared to the control. ALP at 1 and 7 days was similar to the control. MTA and CSC had greater ALP activity at 3 days when compared to control. All the materials present higher mineralized nodules when compared with the control. SEM analysis showed structures suggesting the presence of calcium phosphate on the surface of materials demonstrating bioactivity. Ytterbium oxide proved to be a properly radiopacifying agent for calcium silicate-based cement since it did not affected the physicochemical and biological properties besides preserving the bioactive potential of this material.
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http://dx.doi.org/10.1590/0103-6440201802033DOI Listing
April 2019

Solubility, porosity and fluid uptake of calcium silicate-based cements.

J Appl Oral Sci 2018 21;26:e20170465. Epub 2018 May 21.

Departamento de Odontologia Restauradora, Faculdade de Odontologia de Araraquara, Universidade Estadual Paulista, Araraquara, São Paulo, Brasil.

Objective: To evaluate the absorption/fluid uptake, solubility and porosity of White mineral trioxide aggregate (MTA) Angelus, Biodentine (BIO), and zinc oxide-eugenol (ZOE).

Material And Methods: Solubility was evaluated after immersion in distilled water for 7 and 30 days. Porosity was evaluated using digital inverted microscope, scanning electron microscope (SEM) and micro-computed tomography (micro-CT). For the fluid uptake test, specimens were immersed in Hank's balanced salt solution (HBSS) for 1, 7, 14 and 28 days. Fluid absorption, solubility and porosity of the materials were measured after each period. Statistical evaluation was performed using one-way analysis of variance (ANOVA) and Tukey tests, with a significance level at 5%.

Results: After 7 and 30 days, BIO showed the highest solubility (p<0.05). All methods demonstrated that MTA had total porosity higher than BIO and ZOE (p<0.05). Micro-CT analysis showed that MTA had the highest porosity at the initial period, after its setting time (p<0.05). After 7 and 30 days, ZOE had porosity lower than MTA and BIO (p<0.05). Absorption was similar among the materials (p>0.05), and higher fluid uptake and solubility were observed for MTA in the fluid uptake test (p<0.05).

Conclusions: BIO had the highest solubility in the conventional test and MTA had higher porosity and fluid uptake. ZOE had lower values of solubility, porosity and fluid uptake. Solubility, porosity and fluid uptake are related, and the tests used provided complementary data.
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http://dx.doi.org/10.1590/1678-7757-2017-0465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5953561PMC
May 2018

Evaluation of physicochemical properties of root-end filling materials using conventional and Micro-CT tests.

J Appl Oral Sci 2017 Jul-Aug;25(4):374-380

Universidade Estadual Paulista, Faculdade de Odontologia, Departamento de Odontologia Restauradora, Araraquara, SP, Brasil.

Objective: To evaluate solubility, dimensional stability, filling ability and volumetric change of root-end filling materials using conventional tests and new Micro-CT-based methods.

Material And Methods: 7.

Results: The results suggested correlated or complementary data between the proposed tests. At 7 days, BIO showed higher solubility and at 30 days, showed higher volumetric change in comparison with MTA (p<0.05). With regard to volumetric change, the tested materials were similar (p>0.05) at 7 days. At 30 days, they presented similar solubility. BIO and MTA showed higher dimensional stability than ZOE (p<0.05). ZOE and BIO showed higher filling ability (p<0.05).

Conclusions: ZOE presented a higher dimensional change, and BIO had greater solubility after 7 days. BIO presented filling ability and dimensional stability, but greater volumetric change than MTA after 30 days. Micro-CT can provide important data on the physicochemical properties of materials complementing conventional tests.
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http://dx.doi.org/10.1590/1678-7757-2016-0454DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595109PMC
October 2017

Physicochemical Properties and Dentin Bond Strength of a Tricalcium Silicate-Based Retrograde Material.

Braz Dent J 2017 Jan-Feb;28(1):51-56

Department of Restorative Dentistry, Araraquara Dental School, UNESP - Universidade Estadual Paulista, Araraquara, SP, Brazil.

The aim of this study was to evaluate the physicochemical properties and the apical dentin bond strength of the tricalcium silicate-based Biodentine in comparison to white MTA and zinc oxide eugenol-based cement (ZOE). Setting time and radiopacity were evaluated according to ISO 6876:2012 specification. Final setting time, compressive strength and pH were also assessed. Material's bond strength to the apical root canal dentin was measured by the push-out assay. Data were analyzed by ANOVA and Tukey-Krammer post-hoc test. Biodentine presented the shortest initial (16.2±1.48 min) and final setting time (35.4±5.55 min). Radiopacity of Biodentine (2.79±0.27 mmAl) does not agree with ISO 6876:2012 specifications. On the other hand, Biodentine showed higher compressive strength after 21 days (37.22±5.27 MPa) and higher dentin bond strength (11.2±2.16 MPa) in comparison to white MTA (27.68±3.56 MPa for compressive strength and 2.98±0.64 MPa for bond strength) (p<0.05). Both MTA and Biodentine produced an alkaline environment (approximately pH 10) (p>0.05) compared to ZOE (pH 7). It may be concluded that Biodentine exhibited faster setting, higher long-term compressive strength and bond strength to the apical dentin than MTA and ZOE.
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http://dx.doi.org/10.1590/0103-6440201701135DOI Listing
January 2018

A Novel Model for Evaluating the Flow of Endodontic Materials Using Micro-computed Tomography.

J Endod 2017 May 3;43(5):796-800. Epub 2017 Mar 3.

Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University, Araraquara, São Paulo, Brazil.

Introduction: Flow and filling ability are important properties of endodontic materials. The aim of this study was to propose a new technique for evaluating flow using micro-computed tomographic (μCT) imaging.

Methods: A glass plate was manufactured with a central cavity and 4 grooves extending out horizontally and vertically. The flow of MTA-Angelus (Angelus, Londrina, PR, Brazil), zinc oxide eugenol (ZOE), and Biodentine (BIO) (Septodont, Saint Maur des Fossés, France) was evaluated using International Standards Organization (ISO) 6876/2002 and a new technique as follows: 0.05 ± 0.005 mL of each material was placed in the central cavity, and another glass plate and metal weight with a total mass of 120 g were placed over the material. The plate/material set was scanned using μCT imaging. The flow was calculated by linear measurement (mm) of the material in the grooves. Central cavity filling was calculated in mm in the central cavity. Lateral cavity filling (LCF) was measured by LCF mean values up to 2 mm from the central cavity. Data were analyzed statistically using analysis of variance and Tukey tests with a 5% significance level.

Results: ZOE showed the highest flow rate determined by ISO methodology (P < .05). Analysis performed using μCT imaging showed MTA-Angelus and ZOE had higher linear flow rates in the grooves. Central cavity filling was similar for the materials. However, LCF was higher for BIO versus ZOE.

Conclusions: Although ZOE presented better flow determined by ISO methodology, BIO showed the best filling ability. The model of the technique proposed for evaluating flow using μCT imaging showed proper and reproducible results and could improve flow analysis.
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http://dx.doi.org/10.1016/j.joen.2016.12.002DOI Listing
May 2017

Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements.

Braz Dent J 2016 Sep-Oct;27(5):508-514

Department of Restorative Dentistry, Araraquara Dental School, UNESP - Universidade Estadual Paulista, Araraquara, SP, Brazil.

Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO2) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO2. The following materials were evaluated: WMTA; PC 70% + ZrO2 30%; WMTA+ AgNPs; and PC 70% + ZrO2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL-1. The obtained data were submitted to ANOVA and Tukey tests (p<0.05). The addition of AgNPs to WMTA increased the pH, lowered the solubility and the initial and final setting times. The addition of AgNPs to PC/ZrO2 maintained the pH, lowered the solubility, and increased the setting time and compressive strength. The radiopacity of all materials was higher than 4 mmAl. The addition of AgNPs promoted an increase in antibacterial activity for calcium silicate cements and favored the physicochemical and mechanical properties of the materials.
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http://dx.doi.org/10.1590/0103-6440201600689DOI Listing
April 2017

Effect of addition of nano-hydroxyapatite on physico-chemical and antibiofilm properties of calcium silicate cements.

J Appl Oral Sci 2016 May-Jun;24(3):204-10

- Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, Departamento de Odontologia Restauradora, Araraquara, SP, Brasil.

Objective: Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn).

Material And Methods: White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance.

Results: There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days.

Conclusions: The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement.
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http://dx.doi.org/10.1590/1678-775720150422DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5022225PMC
December 2016

Push-out Bond Strength of Root-end Filling Materials.

Braz Dent J 2016 May-Jun;27(3):332-5

Department of Restorative Dentistry, Araraquara Dental School, UNESP - Universidade Estadual Paulista, Araraquara, SP, Brazil, Universidade Estadual Paulista, Department of Restorative Dentistry, Araraquara Dental School, Universidade Estadual Paulista, Araraquara SP , Brazil.

The aim of this study was to evaluate the bond strength of root-end filling materials. Forty 2-mm-thick slices were obtained from human single-rooted teeth. After root canal preparation using a 1.5 mm diameter cylindrical drill, the dentinal walls were prepared by diamond ultrasonic tip (CVD T0F-2). The specimens were divided according the material (n=10): MTA Angelus (MTAA), MTA Sealer (MTAS, experimental), Sealer 26 (S26) and zinc oxide and eugenol cement (ZOE). The push-out test was performed in a mechanical test machine (EMIC DL 2000) at 1 mm/min speed. The failure type was evaluated by stereomicroscopy. The results were subjected to ANOVA and Tukey test, at 5% significance level. MTAA (19.18 MPa), MTAS (19.13 MPa) and S26 (15.91 MPa) showed higher bond strength (p<0.05). ZOE (9.50 MPa) showed the least bond strength values (p<0.05). Adhesive failure was prevalent in all groups, except for ZOE, which showed mixed failures. It was concluded that root-end filling materials MTA Angelus, MTA Sealer and Sealer 26 showed higher bond strength to dentinal walls than zinc oxide and eugenol cement after retrograde preparation.
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http://dx.doi.org/10.1590/0103-6440201600340DOI Listing
March 2017

Influence of Concentration and Agitation of Sodium Hypochlorite and Peracetic Acid Solutions on Tissue Dissolution.

J Contemp Dent Pract 2015 11 1;16(11):876-9. Epub 2015 Nov 1.

Department of Restorative Dentistry, Araraquara Dental School, Sao Paulo State University, Araraquara, Sao Paulo, Brazil.

Aim And Objective: To evaluated the tissue dissolution of sodium hypochlorite (NaOCl) and peracetic acid (PA) solutions at different concentrations, with or without ultrasonic agitation.

Materials And Methods: The following solutions were analyzed: 2.5% NaOCl, 0.5, 1 and 2% PA, 1% PA associated with 6.5% hydrogen peroxide (HP) and saline. Fragments of bovine pulp tissue with 25 ± 2g mg were immersed into test tubes containing 4 mL of the solutions for 10 minutes. In the groups with agitation, pulp tissues were submitted to 2 cycles of 1 minute of ultrasonic agitation. The specimens were weighed after the removal from the solutions. The percentage of mass loss was calculated according to the difference of mass before and after exposure to solutions. Data were submitted to ANOVA and Tukey tests (p < 0.05).

Results: A total of 2.5% NaOCl with or without agitation showed the higher tissue dissolution (between 64.5 and 67% of mass reduction) (p < 0.005). By comparing the PA solutions, the concentrations of 1 and 2% with or without agitation and the concentration of 0.5% with agitation showed similar dissolution activity (between 35.4 and 44% of mass reduction). The use of the ultrasonic agitation promoted an increase of the dissolution ability only for 0.5% PA.

Conclusion: Peracetic acid solution has pulp tissue dissolution. However, this ability is lower than 2.5% NaOCl solution.

Clinical Significance: The sodium hypochlorite solution shows higher ability to dissolve tissue than PA.
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http://dx.doi.org/10.5005/jp-journals-10024-1775DOI Listing
November 2015

Biocompatibility and bioactivity of calcium silicate-based endodontic sealers in human dental pulp cells.

J Appl Oral Sci 2015 Oct;23(5):467-71

Departamento de Odontologia Restauradora, Escola de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brazil.

Unlabelled: Mineral Trioxide Aggregate (MTA) is a calcium silicate-based material. New sealers have been developed based on calcium silicate as MTA Fillapex and MTA Plus.

Objective: The aim of this study was to evaluate biocompatibility and bioactivity of these two calcium silicate-based sealers in culture of human dental pulp cells (hDPCs).

Material And Methods: The cells were isolated from third molars extracted from a 16-year-old patient. Pulp tissue was sectioned into fragments with approximately 1 mm3 and kept in supplemented medium to obtain hDPCs adherent cultures. Cell characterization assays were performed to prove the osteogenic potential. The evaluated materials were: MTA Plus (MTAP); MTA Fillapex (MTAF) and FillCanal (FC). Biocompatibility was evaluated with MTT and Neutral Red (NR) assays, after hDPCs exposure for 24 h to different dilutions of each sealer extract (1:2, 1:3 and 1:4). Unexposed cells were the positive control (CT). Bioactivity was assessed by alkaline phosphatase (ALP) enzymatic assay in cells exposed for one and three days to sealer extracts (1:4 dilution). All data were analyzed by ANOVA and Tukey post-test (p≤0.05%).

Results: MTT and NR results showed suitable cell viability rates for MTAP at all dilutions (90-135%). Cells exposed to MTAF and FC (1:2 and 1:4 dilutions) showed significant low viability rate when compared to CT in MTT. The NR results demonstrated cell viability for all materials tested. In MTAP group, the cells ALP activity was similar to CT in one and three days of exposure to the material. MTAF and FC groups demonstrated a decrease in ALP activity when compared to CT at both periods of cell exposure.

Conclusions: The hDPCs were suitable for the evaluation of new endodontic materialsin vitro. MTAP may be considered a promising material for endodontic treatments.
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http://dx.doi.org/10.1590/1678-775720150170DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4621938PMC
October 2015

Physicochemical properties of calcium silicate cements associated with microparticulate and nanoparticulate radiopacifiers.

Clin Oral Investig 2016 Jan 8;20(1):83-90. Epub 2015 May 8.

Araraquara School of Dentistry, Araraquara, São Paulo, Brazil.

Objectives: The objective of this paper was to evaluate the physicochemical properties of calcium silicate cements with different chemical compositions, associated with radiopacifying agents.

Materials And Methods: Mineral trioxide aggregate (MTA) Angelus, calcium silicate cement with additives (CSC), and resinous calcium silicate cement (CSCR) were evaluated, with the addition of the following radiopacifiers: microparticles (micro) or nanoparticles (nano) of zirconium oxide (ZrO(2)), niobium oxide (Nb(2)O(5)), bismuth oxide (Bi(2)O(3)), or calcium tungstate (CaWO(4)). Setting time was evaluated using Gilmore needles. Solubility was determined after immersion in water. The pH and calcium ion release were analyzed after 3, 12, and 24 h and 7, 14, and 21 days. The data obtained were submitted to analysis of variance and Tukey's test, at a level of significance of 5 %.

Results: CSC + CaWO(4) and CSCR + ZrO(2) micro, Nb(2)O(5) and CaWO(4) presented results similar to MTA, with a shorter final setting time than the other associations. CSC and CSCR+ ZrO(2) micro presented a higher degree of flow. All the cements evaluated presented low solubility. The materials presented alkaline pH and released calcium ions.

Conclusions: ZrO(2) micro radiopacifier may be considered a potential substitute for Bi(2)O(3) when associated with CSC or CSCR.

Clinical Relevance: The proposed materials, especially when associated with ZrO(2), are potential materials for use as alternatives to MTA.
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http://dx.doi.org/10.1007/s00784-015-1483-7DOI Listing
January 2016

Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction.

Braz Oral Res 2015 10;29:56. Epub 2015 Apr 10.

Department of Restorative Dentistry, Araraquara School of Dentistry, Universidade Estadual Paulista, Araraquara, SP, Brazil.

The aim of this study was to evaluate the ability of gutta-percha and a thermoplastic synthetic polymer (Resilon) to fill simulated lateral canals, using warm vertical compaction. Forty-five single-rooted human teeth were prepared using the rotary crown-down technique. Artificial lateral canals were made at 2, 5, and 8 mm from the working length (WL) in each root. The specimens were divided into three groups (n = 15), according to the filling material: Dentsply gutta-percha (GD), Odous gutta-percha (GO), and Resilon cones (RE). The root canals were obturated using warm vertical compaction, without endodontic sealer. The specimens were subjected to a tooth decalcification and clearing procedure. Filling of the lateral canals was analyzed by digital radiography and digital photographs, using the Image Tool software. The data were subjected to the Kruskal-Wallis and Dunn tests at 5% significance. RE had the best filling ability in all root thirds (p < 0.05), with similar results for GO in the coronal third. In the middle and apical thirds, GD and GO had similar results (p > 0.05). Resilon may be used as an alternative to gutta-percha as a solid core filling material for use with the warm vertical compaction technique. The study findings point to the potential benefit of the warm vertical compaction technique for filling lateral canals, and the study provides further information about using Resilon and gutta-percha as materials for the warm vertical compaction technique.
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http://dx.doi.org/10.1590/1807-3107BOR-2015.vol29.0056DOI Listing
July 2015

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

J Conserv Dent 2015 Mar-Apr;18(2):105-8

Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil.

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.
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http://dx.doi.org/10.4103/0972-0707.153066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4379647PMC
April 2015

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

Int Sch Res Notices 2015 23;2015:874283. Epub 2015 Feb 23.

Department of Restorative Dentistry, Araraquara Dental School, University of Estadual Paulista (UNESP), 14801-903 Araraquara, SP, Brazil.

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.
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http://dx.doi.org/10.1155/2015/874283DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4897117PMC
June 2016
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