Search

AIM To evaluate possible modifications in root canal sealers subjected to a variety of heating conditions using vibrational spectroscopy and analysis of physical and chemical properties. METHODOLOGY EndoSequence BC Sealer HiFlow, Bio-C Sealer, BioRoot RCS and AH Plus were analysed chemically using Raman spectroscopy (25-220 °C) and Fourier-transform infrared spectroscopy (FT-IR) (37-100 °C ). For FT-IR, the materials were tested individually and mixed with root dentine powder. Scanning electron microscopy (SEM) and coupled energy dispersive spectroscopy (EDS) were used to evaluate surface and chemical elements. ISO 6876-2012 and ASTM-C266-07 specifications were followed to evaluate flow, setting time (moist and dry), solubility and radiopacity. Also, pH analysis at 37 and 100 °C was performed. Shapiro-Wilk and Mixed ANOVA (within and between the effects of the subjects), Levene, and a post hoc analyses with Bonferroni correction were performed (P

Made available in DSpace on 2020-12-12T00:57:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Aim: To assess the effect of immersion in distilled water or phosphate-buffered saline (PBS) on the solubility, volumetric change and presence of voids of calcium silicate-based root canal sealers (TotalFill BC, Sealer Plus BC and Bio-C), in comparison with the gold standard epoxy resin-based sealer (AH Plus). Methodology: All properties were evaluated after immersion in distilled water or PBS. Solubility was determined by the percentage of mass loss, whereas volumetric change and presence of voids were evaluated by micro-computed tomography, after 7 days of immersion. The volumetric change and percentage of voids between the baseline (after setting) and the experimental period were calculated. Statistical analysis was performed using one-way anova and Tukey's or Student's t-tests (α = 0.05). Results: The calcium silicate-based sealers had significantly greater solubility and volumetric loss than AH Plus, after immersion in distilled water or PBS (P 0.05). Regarding the volumetric change, AH Plus had a volume increase, with similar values in distilled water and PBS (P > 0.05). TotalFill BC, Sealer Plus BC and Bio-C had a similar volumetric change (P > 0.05). The calcium silicate-based materials had the greatest solubility and volume loss after immersion in distilled water (P 0.05). Conclusions: TotalFill BC, Sealer Plus BC and Bio-C had significantly greater solubility and volumetric loss than AH Plus. Although storage in PBS significantly reduced the solubility and volumetric change of calcium silicate-based sealers, their solubility remained above that recommend by ISO 6876. All the sealers evaluated had low and similar voids, even after immersion in distilled water or PBS. Department of Restorative Dentistry School of Dentistry São Paulo State University (Unesp) Department of Restorative Dentistry School of Dentistry São Paulo State University (Unesp) FAPESP: 2016/00321-0 FAPESP: 2017/14305-9 FAPESP: 2017/19049-0 CNPq: 302206/2017-5

Aim To evaluate the abilities of three calcium silicate-based pulp-capping materials (ProRoot MTA, TheraCal LC, and a prototype tricalcium silicate cement) to produce apatite-like precipitates after being subcutaneously implanted into rats. Methodology Polytetrafluoroethylene tubes containing each material were subcutaneously implanted into the backs of Wistar rats. At 7, 14, and 28 days post-implantation, the implants were removed together with the surrounding connective tissue, and fixed in 2.5% glutaraldehyde in cacodylate buffer. The chemical compositions of the surface precipitates formed on the implants were analyzed with scanning electron microscopy-electron probe microanalysis (SEM-EPMA). The distributions of calcium (Ca) and phosphorus (P) at the material-tissue interface were also analyzed with SEM-EPMA. Comparisons of the thicknesses of the Ca- and P-rich areas were performed using Friedman test followed by Scheffe's test at a significant level of 5%. Results All three materials produced apatite-like surface precipitates containing Ca and P. For each material, elemental mapping detected a region of connective tissue in which the concentrations of Ca and P were higher than those seen in the surrounding connective tissue. The thickness of this Ca- and P-rich region exhibited the following pattern: ProRoot MTA > prototype tricalcium silicate cement ≥ TheraCal LC. ProRoot MTA had a significantly thicker layer of Ca and P than the other materials at all time points (P < 0.05), and a significant difference was detected between the prototype cement and TheraCal LC at 28 days (P < 0.05). Conclusions After being subcutaneously implanted, all of the materials produced Ca- and P-containing surface precipitates and a Ca- and P-rich layer within the surrounding tissue. The thickness of the Ca- and P-rich layer of ProRoot MTA was significantly thicker than that of the other materials. This article is protected by copyright. All rights reserved.

Aim To evaluate the influence of the addition of microparticulate (micro) and nanoparticulate (nano) zirconium oxide (ZrO2) and niobium pentoxide (Nb2O5) to a calcium silicate-based cement (CS) on the subcutaneous healing process in rats compared with MTA Angelus™. Methodology In each rat, two polyethylene tubes filled with the following materials: (i) MTA; (ii) CS + ZrO2micro; (iii) CS + ZrO2nano; (iv) CS + Nb2O5micro or (v) CS + Nb2O5nano were implanted subcutaneously; empty polyethylene tubes were used in the Control group. After 7, 15, 30 and 60 days, the specimens (n = 5 per group in each period) were fixed and embedded in paraffin. Masson's trichrome sections were used to obtain the volume density of the inflammatory cells (VvIC) and fibroblasts (VvFb). The sections were also stained with Picrosirius-red to calculate the birefringent collagen content. Fibroblast growth factor-1 (FGF-1) was detected by immunohistochemistry, and the number of immunolabelled cells was obtained. The data were subjected to two-way anova followed by Tukey's test (P ≤ 0.05). Results At all periods, the VvIC was significantly lower (P

AIM To evaluate mineral trioxide aggregate (MTA), Biodentine and several formulations of calcium aluminate cements (CACb) in terms of their ability to release calcium ions (Ca2+ ) and form apatite-like precipitates after short-term immersion in phosphate-buffered saline (PBS) and its influence on the bond strength to the root-end cavity. METHODOLOGY Ten samples of MTA, Biodentine, CACb and calcium-enriched aluminate cement (CACb+) were placed in contact with PBS or deionized water for 14 days. The cement surfaces were analysed using SEM, EDS-X and FTIR. Eighty standardized root-end cavities filled with the cements (ten samples of each cement) were immersed in PBS or deionized water for 14 days, and the bond strengths were measured. Data from the push-out test were analysed using two-way ANOVA and Tukey's tests (α = 0.05). RESULTS A gradual decrease was observed in Ca2+ concentrations and pH of all solutions. FTIR bands of different phases of hydroxyapatite were identified. Crystalline formation was observed on the surface of all cements after immersion in PBS. No significant difference was observed in the bond strength of the test materials (P > 0.05); however, all cements without contact with the solution revealed significantly lower bond strength values than those in contact with the solution (P

To investigate the retreatability of two calcium silicate-based materials (BioRoot RCS, Septodont, Saint-Maur-des-Fossés, France and GuttaFlow Bioseal, Colténe/Whaledent AG, Langenau, Germany) using rotary instrumentation combined with supplementary irrigant agitation techniques using extracted teeth in a laboratory setting.The root canals of extracted single-rooted mandibular premolars were prepared to size 40, .04 taper and randomly divided into two experimental groups (n = 36) depending on the root filling material. Root canals were filled with gutta-percha and GuttaFlow Bioseal (GB, group 1) or BioRoot RCS (BR, group 2), scanned using a micro-CT scanner and stored in phosphate-buffered saline for 4 months. Removal of root filling was performed with rotary instruments, and specimens were randomly allocated to one of the subgroups for supplementary irrigant agitation (n = 12): subgroup A, syringe irrigation (control); subgroup B, Tornado Brush (M.I.B, Suresnes, France) and subgroup C, ultrasonically activated irrigation. Specimens were re-scanned with micro-CT to calculate the volume of remnant root filling material. Data were analysed statistically by two-way ANOVA and post hoc Tukey's tests (P = 0.05).Specimens filled with GuttaFlow Bioseal were associated with a significantly smaller volume of root filling remnants compared with BioRoot RCS (P 0.05). There was no significant difference between the supplementary irrigant agitation subgroups in the removal of GB (P 0.05). In group 2 (BioRoot RCS), subgroups B (Tornado Brush) and C (ultrasonically activated irrigation) were associated with a significantly smaller volume of root filling remnants compared with subgroup A (syringe irrigation) (P 0.05). There was no significant difference between subgroups B and C (P 0.05).Significantly smaller volumes of root filling remnants of GuttaFlow Bioseal, than BioRoot RCS, were present after their removal with rotary instruments and irrigation. Supplementary irrigant agitation techniques were associated with smaller volumes of remnants during the removal of BioRoot RCS but not that of GuttaFlow Bioseal.

Aim To evaluate the effect of 17% ethylenediaminetetraacetic acid (EDTA), 2.25% peracetic acid (PA) or 10% citric acid (CA) on the push-out bond strength of calcium silicate-based endodontic sealers [MTA Fillapex (Angelus, Londrina, Brazil) and Total Fill BC Sealer (FKG, La Chaux-de-Fonds, Switzerland)] to root dentine after different periods of immersion in phosphate-buffered saline (PBS). AH Plus (Dentsply DeTrey, Konstaz, Germany) was used as a reference material for comparison. Methodology Thirty human maxillary incisors were selected and three 1-mm discs were obtained from the middle third of each root. On the axial surface of each disc, three 0.8-mm-diameter holes were drilled through the dentine. After standardized irrigation, each dentine disc from the same root was treated for smear-layer removal with one of the three tested chelating solutions: EDTA, PA or CA. After that, the holes were dried with paper points and filled with one of the three test root canal sealers. The filled dental slices were further immersed in PBS solution (pH 7.2) for 7 days (T1) or 30 days (T2) at 37 °C, before the push-out assay. Friedman, Kruskal–Wallis and Mann–Whitney tests were used respectively to estimate the impact of the independent variables (solutions, sealers and period of PBS immersion) on the push-out bond strength. The level for significance was set at α = 5% and data were further subjected to a Bonferroni correction. Results Solutions and periods of immersion did not significantly influence the displacement resistance (P = 0.285, and P = 0.104, respectively) of sealers to root dentine. On the other hand, the type of sealer significantly affected the push-out bond strength (P = 0.000). AH Plus was associated with greater resistance to dislodgment compared with Total Fill BC Sealer and MTA Fillapex (P = 0.000). MTA Fillapex resulted in the lowest push-out bond strength (P = 0.000). Conclusion The use of different chelating agents did not influence the push-out bond strength of endodontic sealers. Calcium silicate-based sealers had lower push-out bond strength values compared with a conventional epoxy resin-based sealer (AH Plus).

To evaluate the effect of prior application of several intracanal medicaments on the push-out bond strength of ProRoot MTA and Biodentine.Sixty freshly extracted maxillary anterior teeth were sectioned below the cementoenamel junction, and the root canals instrumented using rotary files. Thereafter, a parallel post drill was used to obtain a standardized root canal dimension. The roots were randomly assigned into one of the following groups with respect to the intracanal medicament applied: group 1: calcium hydroxide (CH) powder (Merck, Darmstadt, Germany) mixed with distilled water; group 2: a mixture of metronidazole, ciprofloxacin and minocycline (triple antibiotic paste); group 3: a combination of amoxicillin and clavulanic acid (Augmentin; Champs Pharmacy, San Antonio, TX, USA); group 4: an antibiotic-corticoid compound paste (Ledermix; Riemser, Greifswald, Germany); and group 5: no medicament (control). Following removal of medicaments with instrumentation and irrigation, the roots were cut into 1-mm-thick parallel transverse sections in a coronal-to-apical direction (5 slices/tooth). Thereafter, the specimens were divided into two subgroups according to the calcium silicate cement applied (n = 30/group): (i) ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK, USA) and (ii) Biodentine (Septodont, Saint-Maur-des-Fosses, France). A push-out test was performed, and the data were analysed statistically using two-way anova and Tukey's post hoc test.Regardless of the type of intracanal medicament used, Biodentine had significantly higher bond strength than MTA (P0.05). The highest push-out bond strength results were obtained in CH-treated dentine. Compared with other medicaments, this value was only significantly higher than that of Ledermix (P0.05). In both the MTA and Biodentine groups, pairwise comparisons between other medicaments showed similar debonding values (P0.05).Biodentine had a higher bond strength to root canal dentine than ProRoot MTA. Prior CH in distilled water intracanal placement increased the dislodgment resistance of both calcium silicate cements.

Aim: To evaluate the cytocompatibility, bioactive potential, antimicrobial and antibiofilm activities of an experimental calcium silicate-based endodontic sealer, in comparison with TotalFill BC Sealer and AH Plus. Methodology: Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of the Saos-2 cells to the sealer extracts (1 : 2, 1 : 4, 1 : 8, 1 : 16 and 1 : 32 dilutions) for 24 h. The sealers were manipulated and placed in 12-well culture plates and exposed to ultraviolet light; then, 5 mL of DMEM without serum was added. Cell bioactivity was evaluated by alkaline phosphatase activity (ALP) and Alizarin red staining (ARS). Antimicrobial and antibiofilm activities were evaluated by direct contact test (DCT) on planktonic cells (DCTPC) and modified DCT on biofilm formed in bovine dentine blocks (MDCT). MTT, NR and ALP data were analysed by two-way anova and Bonferroni tests; ARS data by anova and Tukey's tests; and the microbiological data by Kruskal–Wallis and Dunn tests (α = 0.05). Results: The experimental sealer, TotalFill BC and AH Plus were not cytotoxic to Saos-2, in comparison with the negative control (P > 0.05). Greater ALP was observed after 7 days of exposure of Saos-2 to AH Plus and the experimental sealer (P

AIM To evaluate the inflammatory response and ability to induce mineral deposition through histological and immunohistochemical analysis for osteocalcin (OCN), osteopontin (OPN) and bone sialoprotein (BSP) of a new calcium silicate-based cement, Bio-C Pulpo (Angelus), compared to white mineral trioxide aggregate (White MTA-Ang) (Angelus). METHODOLOGY Polyethylene tubes containing Bio-C Pulpo and White MTA-Ang as well as empty tubes were implanted into the dorsal connective tissue of 30 Wistar rats, which were arranged in five groups according to the period of analysis: 7, 15, 30, 60 and 90 days. After each experimental period, the tubes with surrounding tissue were removed and histologically processed to be analysed using haematoxylin-eosin and immunohistochemistry for the detection of OCN, OPN and BSP. The data were statistically analysed (Friedman's test) at a 5% significance level. RESULTS The inflammatory response observed with Bio-C Pulpo and White MTA-Ang was greater after 7 and 15 days and decreased from 30 days onwards. No significant difference was found between the control, Bio-C Pulpo and White MTA-Ang at the different periods of analysis (P > 0.05). The immunolabelling for OCN, OPN and BSP was more intense for Bio-C Pulpo and White MTA-Ang after 60 and 90 days, but there was no difference between Bio-C Pulpo and White MTA-Ang at the different periods of analysis (P > 0.05). CONCLUSION Bio-C Pulpo is biocompatible and induces immunolabelling of osteogenic markers such as OCN, OPN and BSP similar to White MTA-Ang.

AIM To assess the effect of acid-etching duration time on the compressive strength, microstructure and shear bond strength of All-Bond Universal adhesive to MTA-Angelus (AMTA), and Biodentine (BD). METHODOLOGY Forty-eight cylindrical specimens (4 mm in diameter, 6 mm in height) of AMTA in four groups and 48 specimens of BD in four groups (n = 12) were prepared and stored for 72 h. The control groups were unetched whilst the three experimental groups were acid-etched for 5, 10 and 15 s, respectively, followed by compressive strength testing. The effect of the various acid-etching times on surface micromorphology was evaluated under a scanning electron microscope. Similar groups were bonded using All-Bond Universal and Aelite Flo and shear bond strength was tested. Data were analysed using two-way ANOVA and Tukey tests. RESULTS 10-s and 15-s acid-etching reduced the compressive strength of AMTA and BD (P

Aim To evaluate the ability of a calcium silicate-based sealer (iRoot SP) and an epoxy resin-based sealer (Topseal) using two gutta-percha filling techniques to fill artificial lateral canals (ALCs). Methodology Seventy single-rooted human teeth were selected. Ten of these were used to obtain pilot data. Three ALCs were produced on mesial and distal surfaces of each root, one in each third, using size 10 engine reamers. The roots were randomly assigned to four experimental groups according to the filling technique and sealer used: 1, cold gutta-percha (single-point technique) with iRoot SP (SP-iR); 2, cold gutta-percha (single-point technique) with Topseal (SP-T); 3, continuous wave of condensation technique with iRoot SP (CWC-iR); and 4, continuous wave of condensation technique with Topseal (CWC-T). Digital periapical radiographs were taken. After the sealer had set, the roots were demineralized, cleared in methyl-salicylate and examined under a stereomicroscope. The depth of penetration of sealer and/or gutta-percha into the ALC was scored using a 5-point system, conducting an analysis on four surfaces. Filling scores of 0–1 were considered not acceptable, whilst scores of 2–4 were considered acceptable. Pearson′s chi-square test was used to compare the experimental groups (P

Aim To test the hypothesis that polyacrylic acid-based and calcium silicate materials are able to increase mineral density of artificially demineralized dentine produced by a microcosm model for caries formation. Methodology Forty-five dentine cavities were prepared in nine sound human third molars (five in each tooth). Specimens received a bacterial inoculum and were incubated in BHI plus 5% of sucrose for 96 h to allow biofilm formation. After that, the specimens were scanned in a high energy micro-CT (baseline stack) and then, each cavity was filled with different cements: zinc polycarboxylate (Poly Zinc™, Prevest DenPro, Jammu, India), conventional glass-ionomer (Ketac Molar, 3M ESPE, Seefeld, Germany) and two calcium silicate-based materials (MTA, Angelus, Londrina, Brazil and Biodentine™, Septodont, Saint Maur des Fosses, France) whilst the central cavity was filled with utility wax (negative control). Specimens were kept for 45 days under simulated intrapulpal pressure using simulated body fluid and after, they were again scanned (treated stacks). Reconstruction of the acquired projections was accomplished using standardized parameters, and the percentage mineral density change was calculated around each cavity. Data were tested for normality using the Shapiro-Wilk test, followed by nonparametric methods. Results A microcosm artificial caries model was able to cause dentine demineralization (±90% related to sound dentine). Significant increases in dentine mineral density were achieved using MTA or Poly Zinc™ (43.56% and 41.64% remineralization), followed by Biodentine™ (36.40%) and Ketac Molar (32.54%), P Conclusion All cements increased mineral density in demineralized dentine, but zinc polycarboxylate cement and MTA had greater bioactive potential. Micro-CT proved to be an effective method to evaluate changes in mineral density within dentine in contact with bioactive materials.

Aim: To investigate the composition of materials and leachate of a hydrated prototype cement composed of tricalcium silicate and radiopacifier and compare this to other tricalcium silicate-based cements (Biodentine and Bioaggregate) to assess whether the additives in the proprietary brand cements affect the hydration of the materials, using Intermediate Restorative Material (IRM), a standard root-end filling material as a control. Methodology: The materials investigated included a prototype-radiopacified tricalcium silicate cement, Biodentine, Bioaggregate and Intermediate Restorative Material (IRM). The pH and calcium ion concentration of the leachate were investigated. The hydrated cements were characterized using scanning electron microscopy (SEM) and X-ray energy dispersive analysis (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Results: All the cements tested were alkaline. The tricalcium silicate-based cements leached calcium in solution. Scanning electron microscopy of the prototype-radiopacified tricalcium silicate cement, Biodentine and Bioaggregate displayed hydrating cement grains, surrounded by a matrix composed of calcium silicate hydrate and calcium hydroxide. The presence of calcium hydroxide was evident from the XRD plots. FT-IR indicated the occurrence of a poorly crystalline calcium silicate hydrate. Biodentine displayed the presence of calcium carbonate. Bioaggregate incorporated a phosphate-containing phase. IRM consisted of zinc oxide interspersed in an organic matrix. Conclusions: The hydration of prototype-radiopacified tricalcium silicate cement, Biodentine and Bioaggregate resulted in the formation of calcium silicate hydrate and calcium hydroxide, which was leached in solution. The hydrated materials were composed of a cementitous phase that was rich in calcium and silicon and a radiopacifying material. Biodentine included calcium carbonate, and Bioaggregate included silica and calcium phosphate in the powders. IRM was composed of zinc oxide interspersed in a matrix of organic material., peer-reviewed

Hakki SS, Bozkurt BS, Ozcopur B, Gandolfi MG, Prati C, Belli S. The response of cementoblasts to calcium phosphate resin-based and calcium silicate-based commercial sealers. International Endodontic Journal, 46, 242-252, 2013. Aim To investigate cell viability and gene expression of cementoblasts (OCCM.30) exposed to extractable components released by resin-based sealers with different chemical composition Hybrid Root Seal (HRS), SimpliSeal (SS), Real Seal (RS) and AH Plus (AH) and by a MTA-based sealers Tech Biosealer Endo (TBE). Methodology Discs of all materials were prepared and allowed to set in humid conditions at 37 degrees for 48h. The discs were then incubated for 72h at 37 degrees C to obtain material extracts (1/1) in DMEM. The extracts containing the components released by the sealers were filtered and other dilutions (1/2, 1/4) were prepared from the original solution (1/1). Original and diluted solutions were tested on the cementoblasts. Impedance-based real-time cell analysis (RTCA) was used to evaluate cell viability, quantitative real-time polymerase chain reaction (QRT-PCR) was used to examine the expression of mineralization-related genes (osteocalcin; OCN, Runt-related transcription factor-2; Runx2, collagen type 1; COL I, alkaline phosphatase; ALP). For statistical analysis, one-way analysis of variance (anova) and Tukey's honestly significant difference (HSD) tests were used. Results TBE (1/2), RS (1/2, 1/4), and HRS (1/2, 1/4) significantly decreased cell viability (P

Gandolfi MG, Siboni F, Prati C. Chemical–physical properties of TheraCal, a novel light-curable MTA-like material for pulp capping. International Endodontic Journal, 45, 571–579, 2012. Abstract Aim To evaluate the chemical–physical properties of TheraCal, a new light-curable pulp-capping material composed of resin and calcium silicate (Portland cement), compared with reference pulp-capping materials (ProRoot MTA and Dycal). Methodology Calcium (Ca) and hydroxyl (OH) ion release over 28 days, solubility and water uptake (weight percentage variation, Δ%) at 24 h, cure depth and radiopacity of TheraCal, ProRoot MTA and Dycal were evaluated. Statistical analysis (P

Borges RP, Sousa-Neto MD, Versiani MA, Rached-Junior FA, De-Deus G, Miranda CES, Pecora JD. Changes in the surface of four calcium silicate-containing endodontic materials and an epoxy resin-based sealer after a solubility test. International Endodontic Journal, 45, 419–428, 2012. Abstract Aim To compare the changes in the surface structure and elemental distribution, as well as the percentage of ion release, of four calcium silicate-containing endodontic materials with a well-established epoxy resin-based sealer, submitted to a solubility test. Methodology Solubility of AH Plus, iRoot SP, MTA Fillapex, Sealapex and MTA-Angelus (MTA-A) was tested according to ANSI/ADA Specification 57. The deionized water used in the solubility test was submitted to atomic absorption spectrophotometry to determine and quantify Ca2+, Na+, K+, Zn2+, Ni2+ and Pb2+ ions release. In addition, the outer and inner surfaces of nonsubmitted and submitted samples of each material to the solubility test were analysed by means of scanning electron microscopy and energy-dispersive spectroscopy (SEM/EDX). Statistical analysis was performed by using one-way anova and Tukey’s post hoc tests (α = 0.05). Results Solubility results, in percentage, sorted in an increasing order were −1.24 ± 0.19 (MTA-A), 0.28 ± 0.08 (AH Plus), 5.65 ± 0.80 (Sealapex), 14.89 ± 0.73 (MTA Fillapex) and 20.64 ± 1.42 (iRoot SP). AH Plus and MTA-A were statistically similar (P > 0.05), but different from the other materials (P

Shie MY, Chang HC, Ding SJ. Effects of altering the Si/Ca molar ratio of a calcium silicate cement on in vitro cell attachment. International Endodontic Journal, 45, 337–345, 2012. Abstract Aim To examine the effects of altering the Si/Ca molar ratio (6 : 4, 5 : 5, and 4 : 6) of a quick-setting calcium silicate cement on in vitro cell attachment. Methodology Working time and setting time of three different calcium silicate cements were measured. Alamar Blue was used for real-time and repeated monitoring of cell attachment and proliferation. The Si and Ca ion concentrations of the cell culture medium in the presence of three different calcium silicate cements seeded with MG63 cells were measured. Kinetic immunofluorescent staining of MG63 cells was performed during cell attachment and spreading. Reverse transcription-polymerase chain reaction was employed to determine gene expression in MG63 cells cultured on the cements. One-way analysis of variance was used to evaluate the significance of the differences between the mean values. Results The working time (4–7 min) and setting time (17–24 min) of the cements were shortened with an increase in the Ca content of the calcium silicate powders after mixing the powder with water. In contrast, the higher the Si content in the cement, the more the MG63 cells attached to the cement at all culture time-points, accompanying by the formation of more obvious actin stress fibres. Cell proliferation and differentiation increased significantly (P

Sagsen B, Ustun Y, Demirbuga S, Pala K. Push-out bond strength of two new calcium silicate-based endodontic sealers to root canal dentine. International Endodontic Journal, 44, 1088-1091, 2011. Aim To assess the push-out bond strength of two new calcium silicate-based endodontic sealers in the root canals of extracted teeth. Methodology Thirty extracted single-rooted central incisors of similar sizes were selected randomly and distributed to three groups (n = 10). All canals were instrumented using ProTaper rotary instruments to achieve tapered canal walls. Irrigation was performed using 5 mL 2.5% NaOCl between each instrument, and the smear layer was removed using 5 mL 17% EDTA. The canals were filled with three different sealers using a cold lateral compaction technique: group 1: AH Plus + gutta-percha, group 2: I Root SP + gutta-per- cha and group 3: MTA Fillapex + gutta-percha. Three horizontal sections were prepared at a thickness of 1 mm ±0.1 in the apical, middle and coronal parts of each root. The test specimens were subjected to the push-out test method using a Universal Test Machine (Instron, Canton, MA, USA) that carried 1-mm, 0.5- mm and 0.3-mm plungers for coronal, middle and apical specimens, respectively. The loading speed was 1 mm min )1 . The push-out data were analysed by two- way analysis of variance (anova) and the post hoc Holm-Sidak test, with significance set at P < 0.05. Results In the coronal specimens, there was no signif- icant difference between the sealers. In the middle and apical segments, there was no significant difference between I Root SP and AH Plus groups. However, the I Root SP and AH Plus had significantly higher bond strength values than the MTA Fillapex (P < 0.05). In terms of root segments, the bond strengths in the middle specimens and the apical specimens were higher com- pared with the bond strengths in the coronal specimens (P < 0.05).Therewerenosignificantdifferencesbetween the bond strengths in the middle and apical specimens. Conclusion MTA Fillapex had the lowest push-out bond values to root dentine compared with other

Han L, Okiji T. Uptake of calcium and silicon released from calcium silicate–based endodontic materials into root canal dentine. International Endodontic Journal. Aim To compare Biodentine and White ProRoot mineral trioxide aggregate (MTA) with regard to Ca and Si uptake by adjacent root canal dentine in the presence of phosphate-buffered saline (PBS). Methodology Root canals of bovine incisor root segments were instrumented, filled with either Biodentine or MTA (n = 20 each) and then immersed in Ca-and Mg-free PBS for 1, 7, 30 or 90 days (n =5 each). Unfilled, unimmersed dentine specimens (n =5 ) served as controls. The specimens were sectioned longitudinally, and the ultrastructure of the dentine‐ material interface and the elemental composition/ distribution in the material‐adjacent dentine were analysed using a wavelength-dispersive X-ray spectroscopy electron probe microanalyser with image observation function. Data were statistically analyzed using one-way anova and Tukey’s honestly significant difference test or the Mann‐Whitney U-test. Results Along the material‐dentine interface, both materials formed a tag-like structure that was composed of either Ca- and P-rich crystalline deposits or the material itself. The width of a Ca- and Si-rich layer detected along the dentine layer of the material‐ dentine interface showed increases over time. The Caand Si-rich layer width was significantly larger (P < 0.05) in Biodentine than MTA at 30 and 90 days. Conclusions Both Biodentine and MTA caused the uptake of Ca and Si in the adjacent root canal dentine in the presence of PBS. The dentine element uptake was more prominent for Biodentine than MTA.

Gandolfi MG, Taddei P, Siboni F, Modena E, Ginebra MP, Prati C. Fluoride-containing nanoporous calcium-silicate MTA cements for endodontics and oral surgery: early fluorapatite formation in a phosphate-containing solution. International Endodontic Journal, 44, 938–949, 2011. Aim To test the chemical–physical properties and apatite-forming ability of experimental fluoride-doped calcium silicate cements designed to create novel bioactive materials for use in endodontics and oral surgery. Methodology A thermally treated calcium silicate cement (wTC) containing CaCl2 5%wt was modified by adding NaF 1%wt (FTC) or 10%wt (F10TC). Cements were analysed by environmental scanning electron microscopy with energy-dispersive X-ray analysis, IR and micro-Raman spectroscopy in wet conditions immediately after preparation or after ageing in a phosphate-containing solution (Dulbecco’s phosphatebuffered saline). Calcium and fluoride release and pH of the storage solution were measured. The results obtained were analysed statistically (Tukey’s HSD test and two-way anova). Results The formation of calcium phosphate precipitates (spherulites) was observed on the surface of 24 h-aged cements and the formation of a thick bone-like B-type carbonated apatite layer (biocoating) on 28 day-aged cements. The rate of apatite formation was FTC > F10TC > wTC. Fluorapatite was detected on FTC and F10TC after 1 day of ageing, with a higher fluoride content on F10TC. All the cements released calcium ions. At 5 and 24 h, the wTC had the significantly highest calcium release (P < 0.001) that decreased significantly over the storage time. At 3–28 days, FTC and F10TC had significantly higher calcium release than wTC (P < 0.05). The F10TC had the significantly highest fluoride release at all times (P < 0.01) that decreased significantly over storage time. No significant differences were observed between FTC and wTC. All the cements had a strong alkalinizing activity (OH) release) that remained after 28 days of storage. Conclusions The addition of sodium fluoride accelerated apatite formation on calcium silicate cements. Fluoride-doped calcium silicate cements had higher bioactivity and earlier formation of fluorapatite. Sodium fluoride may be introduced in the formulation of mineral trioxide aggregate cements to enhance their biological behaviour. F-doped calcium silicate cements are promising bone cements for clinical endodontic use.

Gandolfi MG, Prati C. MTA and F-doped MTA cements used as sealers with warm gutta-percha. Long-term study of sealing ability. International Endodontic Journal, 43, 889–901, 2010. Abstract Aim To evaluate the long-term sealing ability (up to 6 months) of two experimental calcium silicate MTA cements used as root canal sealers in association with warm gutta-percha. Methodology Calcium silicate (MTA) and calcium-fluoro-silicate powders were prepared. Sodium fluoride was included in FMTA (Fluoride-doped Mineral Trioxide Aggregate) as an expansive and retardant agent. Single-rooted teeth were instrumented with NiTi rotary instruments, filled with warm gutta-percha in association with one of the experimental sealers or with AH Plus as a control (n = 20 for each sealer) and stored at 37 °C. Sealing was assessed at 24, 48 h, 1, 2 weeks and 1, 3, 6 months by a fluid filtration method. Scanning electron microscopy with energy dispersive analysis (SEM/EDX) was used to study the dentine/sealer interface of roots stored for 6 months and the surface of cement disks stored for 24 h. Results All sealers revealed a statistically significant reduction (P

Zhang W, Li Z, Peng B. Ex vivo cytotoxicity of a new calcium silicate–based canal filling material. International Endodontic Journal, 43, 769–774, 2010. Abstract Aim To evaluate the biocompatibility of iRoot SP root canal filling material to L929 mouse fibroblasts. Methodology Specimens of iRoot SP, AH Plus and ProRoot mineral trioxide aggregate (MTA) were prepared for direct contact using the Millipore filter diffusion test, as well as extracts in MTT assay. Mouse fibroblasts (L929) were used as toxicity targets. Differences in cytotoxicity between fresh and set specimens and between root canal material extracts were determined by t-test. A P-value

Chedella SCV, Berzins DW. A differential scanning calorimetry study of the setting reaction of MTA. International Endodontic Journal, 43, 509–518, 2010. Abstract Aim To evaluate the setting of mineral trioxide aggregate (MTA) at various time intervals using differential scanning calorimetry (DSC). Methodology Hydrated MTA and Portland cement were examined with DSC at the following intervals: immediate (0 h), 2 h, 4 h, 12 h, 24 h, 1 week, 1 month, 3 months and 1 year. DSC analysis consisted of a temperature scan from 37 to 640 °C, resulting in thermograms with reaction product decomposition endotherms. The thermogram peak attributed to calcium hydroxide product formation was identified and quantified to serve as an indicator of reaction product formation over time. Unmixed powders of both cements and individual components of MTA were also studied using DSC. The results were analysed with repeated measures anova between time intervals and a t-test between cements. Results A low temperature endotherm attributed to various calcium silicate hydrates showed continual maturation of MTA up to 1 year. The rate of calcium hydroxide formation was greatest between 4 and 24 h after mixing with maximum amounts present at 7 days. Specimens aged greater than 1 month showed a decrease in calcium hydroxide content, presumably because of carbonation reactions. Portland cement had similar thermogram peaks, although the amount of calcium hydroxide formed was generally smaller compared to MTA. The endothermic peaks from the various powders and components were helpful in corroborating the peaks formed in the hydrated cements. Conclusions Hydration reactions and structure maturation in MTA continue well beyond clinically observed setting times.

Aim To identify the suitable ratio of alternative radiopacifiers to impart the necessary radiopacity to calcium silicate cements (CSC) and assess the purity of the radiopacifying agents. Methodology Alternative radiopacifying materials for incorporation into CSC included barium sulphate, titanium oxide, zinc oxide, gold powder and silver/tin alloy. The chemical composition of the alternative radipacifying materials and bismuth oxide, which is used in mineral trioxide aggregate (MTA), was determined using energy dispersive X-ray analysis. In addition, using an aluminium step-wedge and densitometer, the radiopacity of each material was evaluated as recommended by international standards. The optical density was compared with the relevant thickness of aluminium (Al). A commercial MTA and CSC were used as controls. Statistical analysis comparing the radiodensity of the different cements to MTA was performed using anova with P = 0.05 and post hoc Tukey test. Results All percentage replacements of bismuth oxide, gold and silver–tin alloy powder, and the 25% and 30% replacements with barium sulphate and zinc oxide had radiopacities greater than 3 mm thickness of aluminium (Al) recommended by ISO 6876 (2002). The 25% replacement of cement with gold powder and 20% replacement of cement with silver/tin alloy powder exhibited radiopacity values of 8.04 mm Al and 7.52 mm Al, respectively, similar to MTA (P > 0.05). The cement replaced with 20% bismuth oxide showed a radiopacity of 6.83 mm Al, lower than MTA (P = 0.003). Conclusions Silver/tin alloy and gold powder imparted the necessary radiopacity to a calcium silicate-based cement. Barium sulphate was also a suitable radiopacifier together with a lower concentration of silver/tin alloy and gold powder that achieved the radiodensity recommended by ISO 6876. Further research is required to investigate the broader properties of the calcium silicate-based cement with the different radiopacifiers.

Aim To evaluate and compare the push-out bond strength of MTA Fillapex (Angelus, Londrina, Brazil) and iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada) to the dentine walls of root canals. AH Plus (Dentsply DeTrey, Konstaz, Germany) and MTA (Angelus, Londrina, Brazil) were used as reference materials. Methodology Sixty extracted human single-rooted teeth were selected. After standardized canal preparation and irrigation, the canals were dried with paper points and filled with one of four sealers: AH Plus, iRoot SP, MTA and MTA Fillapex. Roots were sectioned, and push-out tests were performed. The values of bond strength were analysed using the Kruskal–Wallis test. Mann–Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05 for the analyses. Results All specimens had measurable adhesion to root dentine and no premature failure occurred. There were significant differences amongst materials (P = 0.000). MTA-filled specimens had higher push-out bond strength values (P = 0.000). AH Plus had significantly higher bond strength than both Fillapex and iRoot SP (P = 0.000). Both Fillapex and iRoot SP had the lowest push-out bond strength amongst all experimental groups (P = 0.000). No difference occurred between the two calcium silicate-based root canal sealers (P = 0.265). Conclusion The adhesion to root dentine associated with newer calcium silicate-based sealers was compromised even when well-monitored laboratory conditions were used.