Effect of a calcium silicate cement and experimental glass ionomer cements containing calcium orthophosphate particles on demineralized dentin.

OBJECTIVE: The study aims to evaluate the effect of a glass ionomer cement (GIC; Fuji 9 Gold Label, GC) with added calcium orthophosphate particles and a calcium silicate cement (CSC; Biodentine, Septodont) regarding ion release, degradation in water, mineral content, and mechanical properties of demineralized dentin samples. METHODS: GIC, GIC + 5% DCPD (dicalcium phosphate dihydrate), GIC + 15% DCPD, GIC + 5% ß-TCP (tricalcium phosphate), GIC + 15% ß-TCP (by mass), and CSC were evaluated for Ca2+/Sr2+/F- release in water for 56 days. Cement mass loss was evaluated after 7-day immersion in water. Partially demineralized dentin disks were kept in contact with materials while immersed in simulated body fluid (SBF) at 37 °C for 56 days. The "mineral-to-matrix ratio" (MMR) was determined by ATR-FTIR spectroscopy. Dentin hardness and elastic modulus were obtained by nanoindentation. Samples were observed under scanning and transmission electron microscopy. Data were analyzed by ANOVA/Tukey test (α = 0.05). RESULTS: Ca2+ release from CSC and GIC (µg/cm2) were 4737.0 ± 735.9 and 13.6 ± 1.6, respectively. In relation to the unmodified GIC, the addition of DCPD or ß-TCP increased ion release (p < 0.001). Only the dentin disks in contact with CSC presented higher MMR (p < 0.05) and mechanical properties than those restored with a resin composite used as control (p < 0.05). Mass loss was similar for GIC and CSC; however, the addition of DCPD or ß-TCP increased GIC degradation (p < 0.05). CONCLUSION: Despite the increase in ion release, the additional Ca2+ sources did not impart remineralizing capability to GIC. Both unmodified GIC and CSC showed similar degradation in water. CLINICAL RELEVANCE: CSC was able to promote dentin remineralization.

The Influence of New Silicate Cement Mineral Trioxide Aggregate (MTA Repair HP) on Metalloproteinase MMP-2 and MMP-9 Expression in Cultured THP-1 Macrophages.

The aim of the present study was to investigate the new silicate cement mineral trioxide aggregate (MTA Repair HP) with respect to its effect on the inflammation process involving the tooth and periodontal tissues. The composition of MTA Repair HP was supplemented with plasticizer agents which can have a negative effect on the modulation of tooth inflammation. The silicate-based material in question is widely used in regeneration of the pulp-dentin complex, treatment of perforations of various locations in the tooth, as well as in surgical treatment of the complications of periapical tissue. The improved bioceramic restorative cement can affect the expression of metalloproteinases MMP-2 and MMP-9 in monocytes/macrophages involved in modulation of inflammation and regenerative processes of the tooth and periodontal tissues. The novel aspect of the present study lies in the application of the model of THP-1 monocyte/macrophage and applying the biomaterial in direct contact with the cells. Hence, it provides a representation of clinical conditions with respect to regenerative pulp and periodontal treatment with the use of MTA Repair HP. A lack of macrophage activation (as measured with flow cytometry) was found. Moreover, the study identified a lack of expression stimulation of the studied metalloproteinases (with the use of Western blotting and fluorescent microscopy). Similarly, no increase in MMP-2 and MMP-9 concentration was found (measured by ELISA method) in vitro when incubated with MTA Repair HP. Based on the results it can be concluded that new MTA Repair HP does not increase the inflammatory response in monocytes/macrophages associated with the activity of the described enzymes. It can also be speculated that they do not affect the process of dentin regeneration in which MMP-2 and MMP-9 play significant roles.

Enhancing the biological activity of vaterite-containing ß-dicalcium silicate cement by silane coupling agent for biomaterials.

Vaterite-containing ß-dicalcium silicate powder (A-V-C2S) was successfully grafting modified by 3-aminopropyltriethoxysilane (APTES) through reflux agitation. The purpose of this work is to fix the amino groups on the vaterite-containing ß-dicalcium silicate (V-C2S) powder's surface, which makes the powder's surface with positive charge, and further enhanced the combination with those negatively charged bioactive molecules or drugs to improve the performance of biomaterials. XRD and FT-IR analysis indicated that N-H groups were successfully grafted onto the surface of the V-C2S sample on the basis of vaterite existence through the process of first grafting then carbonation. Moreover, the best grafting modification that refluxing at 70 °C for 12 h was determined through the quantitative analysis of N-H groups on V-C2S powder's surface. The A-V-C2S sample showed a better apatite formation ability after it was soaked in stimulated body fluid (SBF), indicating that good apatite mineralization. Moreover, the A-V-C2S sample with weak alkali in implanting position could stimulate the attachment, proliferation and improve the activity of MC3T3-E1 cells. Experimental results demonstrated that, A-V-C2S was expected to be a new biomaterial as bone repairing substitute.

Calcium Phosphate Silicate and Calcium Silicate Cements Suppressing Osteoclasts Activity Through Cytokine Regulation.

Calcium phosphate silicate bone cement (CPSC) can stimulate osteoblast proliferation and promote osteogenesis, but how CPSC supress osteoclast activity through cytokine regulation is not clear. In the current study, we synthesized CPSC by incorporating monocalcium phosphate (MCP) into calcium silicate cement (CSC), and analyzed the effects of CSC and CPSC on osteoclast survival with MTT. And we found that both CSC and CPSC medium could decrease osteoclast cell viability, and flow cytometry further revealed that CSC and CPSC could inhibit osteoclast activity. To elucidate the underlying mechanism, related gene and protein level of cytokines that related to osteoclast activity were evaluted. The results demonstrated that osteoclast activity was inhibited in cells treated with cement. The effects were associated with a number of cytokines stimulated by cement. In conclusion, both CSC and CPSC seem to be good substitutes of bone replacement by inhibiting osteoclast activity; the exact mechanism of how they promote bone growth, however, needs further investigations.

Gene Expression Profiling and Molecular Signaling of Various Cells in Response to Tricalcium Silicate Cements: A Systematic Review.

INTRODUCTION: The aim of this study was to present a systematic review investigating the gene expression of various cells (other than dental pulp cells) in response to different variants of tricalcium silicate cements (TSCs). METHODS: A systematic search of the literature was performed by 2 independent reviewers followed by article selection and data extraction. Studies analyzing any cell type except dental pulp stem cells and any variant of tricalcium silicate cement either as the experimental or as the control group were included. RESULTS: A total of 41 relevant articles were included in this review. Among the included studies, ProRoot MTA (Dentsply, Tulsa, OK) was the most commonly studied (69.1%) TSC variant, and 11 cell types were identified, with 13 articles investigating gene expression in osteoblasts. A total of 39 different genes/molecules expressed were found in the selected studies. The experimental group (irrespective of the TSC variant) was identified to express significantly increased gene expression compared with the control group (untreated) in all included studies. Recent studies have provided useful insight into the gene expression and molecular signaling of various cells in response to TSCs, and new elements have been supplied on the pathways activated in this process. CONCLUSIONS: TSCs are capable of eliciting a favorable cellular response in periapical regeneration.

Effect of physicochemical properties of a cement based on silicocarnotite/calcium silicate on in vitro cell adhesion and in vivo cement degradation.

A silicon calcium phosphate cement (Si-CPC) was developed to produce a composite of calcium phosphate and calcium silicate. The silicon cements prepared with low silicon (Si) content were composed of crystalline phases of brushite and silicocarnotite. However, the cements prepared with high Si content were mainly composed of amorphous phases of silicocarnotite, hydroxyapatite and calcium silicate. The cement porosity was about 40% with a shift of the average pore diameter to the nanometric range with increasing Si content. Interestingly, this new cement system provides a matrix with a high specific surface area of up to 29 m(2) g(-1). The cytocompatibility of the new Si-doped cements was tested with a human osteoblast-like cell line (MG-63) showing an enhancement of cell proliferation (up to threefold) when compared with unsubstituted material. Cements with a high silica content also improved the cell attachment. The in vivo results indicated that Si-CPCs induce the formation of new bone tissue, and modify cement resorption. We conclude that this cement provides an optimal environment to enhance osteoblast growth and proliferation that could be of interest in bone engineering.

Osteogenic and anti-osteoporotic effects of risedronate-added calcium phosphate silicate cement.

Osteoporosis greatly impairs bone fracture restoration with bone cement because the accelerated resorption decreases the osseointegration between bone and implants. In this study, we designed a new drug delivery system based on the third generation bisphosphonate risedronate (RA) and the osteogenic calcium phosphate silicate cement (CPSC). The impact of RA on CPSC's material properties and microstructure was evaluated by different characterization methods (µCT, XRD, FTIR, SEM and gas sorption). In addition, in vitro biocompatibility of RA-added CPSC was evaluated (MTT assay, flow cytometry, real-time PCR). In an in vivo study of osteoporotic rabbits, osteoporosis- and bone resorption-related biomarkers were measured over time (ELISA) and local osteogenic and anti-osteoporotic effects investigated (x-ray, CT, histology, PCR arrays). RA decreased the setting rate and compressive strength of CPSC by impeding the hydration of calcium silicate. The overall porosity of CPSC was also decreased with RA. The RA-added CPSC was biocompatible and improved osteoblast proliferation and differentiation. The slow release of RA from CPSC reduced the prevalence of osteoporosis in rabbits and improved peri-implant bone formation and osseointegration. In conclusion, RA-containing CPSC demonstrates its potentials to improve fractural restoration under osteoporotic conditions and should be further engineered to increase its effectiveness in fractural restoration.

Effects of two fast-setting calcium-silicate cements on cell viability and angiogenic factor release in human pulp-derived cells.

Mineral trioxide aggregate (MTA) is considered a pulp-capping agent of choice, but has the drawback of a long setting time. This study aimed to assess two different types of calcium-silicate cements as pulp-capping agents, by investigating their in vitro cytotoxicity and angiogenic effects in human pulp cells. ProRoot MTA, Endocem Zr, and Retro MTA were prepared as set or freshly mixed pellets. Human pulp-derived cells were grown in direct contact with these three cements, Dycal, or no cement, for 7 days. Initial cell attachment, viability, calcium release, and the levels of vascular endothelial growth factor (VEGF), angiogenin, and basic fibroblast growth factor (FGF-2) were evaluated statistically using a linear mixed model (P < 0.05). The biocompatibility of Retro MTA was similar to those of the control and ProRoot MTA. Endocem Zr groups showed fewer and more rounded cells after a 3-day culture; however, the initial cytotoxicity appeared transient. All test materials showed significant increases in calcium concentration compared with the control group (P < 0.05). VEGF and angiogenin levels in ProRoot MTA and Retro MTA groups were significantly higher than those in the Endocem Zr group (P < 0.05). FGF-2 levels were not significantly different between groups (P > 0.05). We demonstrate that Retro MTA, which has a short setting time, has similar biocompatibility and angiogenic effects on human pulp cells, and can therefore potentially be as effective in pulp capping as ProRoot MTA. Endocem Zr showed intermittent cytotoxicity and elicited lower levels of VEGF and angiogenin expression.

Odontoblastic Differentiation, Inflammatory Response, and Angiogenic Potential of 4 Calcium Silicate-based Cements: Micromega MTA, ProRoot MTA, RetroMTA, and Experimental Calcium Silicate Cement.

INTRODUCTION: The aim of this study was to analyze the effects of different calcium silicate-based cements (CSCs) for pulp capping materials including MicroMega MTA (MMTA; MicroMega, Besanchon, France), RetroMTA (RMTA; BioMTA, Seoul, Korea), ProRoot MTA (PMTA; Dentsply, Tulsa, OK), and experimental CSC (ECSC) on odontoblastic differentiation, in vitro angiogenesis, and the inflammatory response in human dental pulp cells. METHODS: Differentiation was evaluated by alkaline phosphatase activity, alizarin red staining, and reverse-transcriptase polymerase chain reaction (RT-PCR) for the marker genes. The levels of inflammatory mediators and cytokines were measured by RT-PCR and an enzyme-linked immunosorbent assay. In vitro angiogenesis was assessed by RT-PCR for angiogenic genes and an endothelial tube formation assay. RESULTS: PMTA, MMTA, and ECSC increased the alkaline phosphatase activity and mineralization nodule formation and up-regulated messenger RNA (mRNA) expression of odontoblastic markers compared with RMTA. In addition, PMTA, MMTA, and ECSC up-regulated the mRNA of angiogenic genes in human dental pulp cells and increased the capillary tube formation of endothelial cells compared with RMTA. However, all CSCs showed similar expression levels of inducible nitric oxide synthase and cyclooxygenase-2 protein as well as proinflammatory mediators such as nitric oxide, prostaglandin E2, tumor necrosis factor alpha, interleukin (IL)-1ß, IL-6, and IL-8 mRNA. CONCLUSIONS: Taken together, our experimental results suggest that all CSCs are favorable materials for pulp capping, but PMTA, MMTA, and ECSC may be recommended over RMTA.

The role of integrin αv in proliferation and differentiation of human dental pulp cell response to calcium silicate cement.

INTRODUCTION: It has been proved that integrin αv activity is related to cell proliferation, differentiation, migration, and organ development. However, the biological functions of integrin αv in human dental pulp cells (hDPCs) cultured on silicate-based materials have not been explored. The aim of this study was to investigate the role of integrin αv in the proliferation and odontogenic differentiation of hDPCs cultured with the effect of calcium silicate (CS) cement and ß-tricalcium phosphate (TCP) cement. METHODS: In this study, hDPCs were cultured on CS and TCP materials, and we evaluated fibronectin (FN) secretion and integrin αv expression during the cell attachment stage. After small interfering RNA transfection targeting integrin αv, the proliferation and odontogenesis differentiation behavior of hDPCs were analyzed. RESULTS: The results indicate that CS releases Si ion-increased FN secretion and adsorption, which promote cell attachment more effectively than TCP. The CS cement facilitates FN and αv subintegrin expression. However, the FN adsorption and integrin expression of TCP are similar to that observed in the control dish. Integrin αv small interfering RNA inhibited odontogenic differentiation of hDPCs with the decreased formation of mineralized nodules on CS. It also down-regulated the protein expression of multiple markers of odontogenesis and the expression of dentin sialophosphoprotein protein. CONCLUSIONS: These results establish composition-dependent differences in integrin binding and its effectiveness as a mechanism regulating cellular responses to biomaterial surface.

Effect of verapamil, a calcium channel blocker, on the odontogenic activity of human dental pulp cells cultured with silicate-based materials.

INTRODUCTION: This study examines how calcium silicate cement extracts influence the behavior of human dental pulp cells (hDPCs) through calcium channels and active mitogen-activated protein kinase pathways, in particular extracellular signal-related kinase (ERK). METHODS: HDPCs are treated with various silicon concentrations both with and without verapamil, after which the cells' viability and odontogenic differentiation markers are determined by using PrestoBlue assay and Western blot, respectively. RESULTS: The silicon promoted cell proliferation and inhibited calcium channel blockers. It was also found that silicon increased ERK and p38 activity in a dose-dependent manner. Furthermore, it raised the expression and secretion of alkaline phosphatase, osteocalcin, dentin sialophosphoprotein, and dentin matrix protein-1. In addition, statistically significant differences (P < .05) have been found in the secretion of osteocalcin in ERK inhibitor + verapamil between the silicon concentrations; these varations are dose-dependent and indicate that ERK signaling is involved in the silicon-induced odontogenic differentiation of hDPCs. CONCLUSIONS: The current study shows that silicon ions released from calcium silicate substrates play a key role in odontoblastic differentiation of hDPCs through calcium channels and modulate ERK activation.

Role of the P38 pathway in calcium silicate cement-induced cell viability and angiogenesis-related proteins of human dental pulp cell in vitro.

INTRODUCTION: This study investigated that calcium silicate (CS) cement may influence the behavior of human dental pulp cells (hDPCs) via mitogen-activated protein kinase pathway, in particular p38. We have addressed that Si ion released from CS cement can influence osmolarity in the medium, which may stimulate hDPC viability and induce angiogenesis-related proteins through stimulation of the nitric oxide synthase and nitric oxide secretion. METHODS: The hDPCs was cultured with CS cement to angiogenesis. Then, cell viability, ion concentration, osmolality, nitric oxide secretion, the von Willebrand factor, and angiopoietin-1 protein expression were examined. RESULTS: CS cement elicited a significant (P < .05) increase of 15%, 20%, and 19% in viability compared with control on days 1, 3, and 5 of cell seeding, respectively. The CS cement consumed calcium and phosphate ions and released more Si ions in medium. The CS significantly (P < .05) increased the osmolality to 303.52 ± 3.07, 315.03 ± 5.80, and 319.95 ± 4.68 mOsm/kg for 1, 3, and 5 days, respectively. P38 was activated through phosphorylation; the phosphorylation kinase was investigated in our cell system after culture with CS cement. Moreover, expression levels for angiopoietin-1 and von Willebrand factor in hDPCs on CS cement were higher than those of the CS + p38 inhibitor (SB203580) group (P < .05) at all of the analyzed time points. CONCLUSIONS: This study showed that CS cement was able to activate the p38 pathway in hDPCs cultured in vitro. Moreover, Si was shown to increase osmolality required to facilitate the angiogenic differentiation of hDPCs via the p38 signaling pathway. When the p38 pathway was blocked by SB203580, the angiogenic-dependent protein secretion was decreased. These findings verified that the p38 pathway plays a key role in regulating the angiogenic behavior of hDPCs cultured on CS cement.

Polycarboxylated microfillers incorporated into light-curable resin-based dental adhesives evoke remineralization at the mineral-depleted dentin.

This study aimed at evaluating the remineralizing properties of three experimental light-curable resin-based dental adhesives containing tailored polycarboxylated microfillers. A co-monomers blend was firstly formulated and then mixed with each of the following microfillers: polycarboxylated bioactive glass (PBAG), polycarboxylated calcium silicates (PCS), and polycarboxylated calcium silicates-doped brushite (PDP). The three experimental and a filler-free control resins were applied onto 10% orthophosphoric acid treated dentin discs and light cured. The specimens were soaked in artificial saliva (AS) for 3, 7, and 14 days. Dentin mineral variation was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and Raman spectroscopy. Confocal laser scanning microscopy (CLSM) was employed to observe the ultra-morphology/nanoleakage along the resin-dentin interface. The bonding ability and the durability of the resin-dentin bonds were investigated through microtensile bond strength (µTBS) test. ATR-FTIR and Raman showed a significant increase of the mineral matrix area ratio and phosphate peak intensity in specimens treated with the experimental resins within 14 days (p < 0.05). No significant increment of minerals was found in untreated specimens or specimens treated using the control filler-free resin (p > 0.05). Dentin treated using PBAG or PCS exhibited higher level of remineralization than the specimens in PDP group. CLSM showed reduction in nanoleakage, although the remineralization of the hybrid layer induced a significant drop in the µTBS after 3-month storage (p < 0.05). The experimental resin-based dental adhesives containing bioactive microfillers remineralize the resin-dentin interfaces when in intimate contact with biological fluids.

Gene expression and cytokine release during odontogenic differentiation of human dental pulp stem cells induced by 2 endodontic biomaterials.

INTRODUCTION: Mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) have shown osteogenic/cementogenic/dentinogenic activities; however, their mechanism of action is not fully understood. We aimed to evaluate the effect of these biomaterials on odontogenic differentiation of human dental pulp stem cells (DPSCs). METHODS: Flow cytometry with stem cell markers for the confirmation of stemness and homogeneity was first performed. Then isolated DPSCs were seeded on prepared discs of MTA, CEM, differentiation medium (DM), and growth medium (GM) and incubated up to 14 days. Concentrations of transforming growth factor-ß1, bone morphogenetic protein (BMP)2, BMP4, and fibroblast growth factor 4 were measured at each interval using an enzyme-linked immunosorbent assay reader. Gene expression of dentin sialophosphoprotein, dentin matrix protein 1, and the cytokines were evaluated by reverse-transcription polymerase chain reaction. To evaluate the cell morphology, scanning electron micrographs were taken; mineralization potential was evaluated using alizarin red S staining. RESULTS: Scanning electron micrographs showed that DPSCs spread/adhered/proliferated similarly on MTA and CEM. On day 14, alizarin red S staining confirmed that mineralization occurred in all groups except GM. Expressions of dentin matrix protein 1 and dentin sialophosphoprotein genes were similar in the CEM, MTA, and DM groups; they were significantly higher compared with the GM group (P < .05). A greater amount of transforming growth factor-ß1 gene was expressed in MTA compared with the other groups (P < .05). However, the expression of fibroblast growth factor 4 and BMP2 genes was significantly greater in the CEM group (P < .05). In all the tested groups, the expression of BMP4 was less than GM (P < .01); however, CEM and DM were similar but more than MTA (P < .05). Concentrations of protein product detected using an enzyme-linked immunosorbent assay reader confirmed these gene expressions. CONCLUSIONS: MTA and CEM can induce osteo-/odontogenic-like phenotype differentiation of human DPSCs; however, they stimulate different gene expressions and growth factor release.

Antiosteoclastogenic activity of silicate-based materials antagonizing receptor activator for nuclear factor kappaB ligand-induced osteoclast differentiation of murine marcophages.

INTRODUCTION: This study investigated whether calcium silicate cement extract exerted antiosteoclastogenic actions in murine RAW 264.7 macrophages cultured with receptor activator for nuclear factor kappaB (RANKL). METHODS: The RAW 264.7 macrophage cell was treated with RANKL to osteoclastogenesis. Then, cell viability, cell death, and cathepsin K expression were examined. RESULTS: The silicon (Si)-inhibited RANKL-induced formation of osteoclasts during the osteoclast differentiation process. It was also found that ≥4 mmol/L Si reduced RANKL-enhanced tartrate-resistant acid phosphatase (TRAP) activity in a dose-dependent manner. Furthermore, Si diminished the expression and secretion of cathepsin K elevated by RANKL and was concurrent with the inhibition of TRAF6 induction and nuclear factor kappaB activation. CONCLUSIONS: The current report shows that silicate abrogated RANKL-induced osteoclastogenesis by retarding osteoclast differentiation. The Si can modulate every cell through dose-dependent in vitro RANKL-mediated osteoclastogenesis, such as the proliferation and fusion of preosteoclasts, and the function of osteoclasts. Therefore, silicate-based materials may be a potential therapeutic agent targeting osteoclast differentiation in bone defects.

The response of cementoblasts to calcium phosphate resin-based and calcium silicate-based commercial sealers.

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° for 48 h. The discs were then incubated for 72 h at 37 °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 < 0.001). AH (1/2, 1/4) and SS (1/2, 1/4) had similar cell viability to the control at 30 h. All tested materials significantly decreased cell viability when compared to the control group except AH (1/2, 1/4) and SS (1/4) at 90 h. All of the tested sealers reduced COL I mRNA expressions when compared to the control. SS was associated with significant increases in OCN and Runx2 mRNA expressions when compared to the control (P < 0.001). Whereas all of the dilutions of TBE, RS and HRS significantly decreased BSP mRNA expressions (P < 0,001), 1/2 and 1/4 dilutions of SS increased BSP mRNA expression (P < 0,001). Except the 1/4 dilutions of AH and SS, all the sealer dilutions significantly reduced ALP mRNA expression in cementoblasts (P < 0,001). CONCLUSIONS: SimpliSeal and AH Plus resulted in more favourable response to cementoblasts because of their regulation potential on the mineralized tissue-associated protein's mRNA expressions.

A study on the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement for dental applications.

The objective of this study was to evaluate the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement. Fifty maxillary anterior teeth were instrumented according to step-back technique and filled with experimental and control materials. To evaluate the sealing ability, a fluid transport model using glucose was employed for quantitative analysis of endodontic microleakage. To evaluate antibacterial activity, E. colias (ATCC 25922) was cultivated on agar plates. Results showed that the sealing ability of Ca3SiO5/CaCl2 composite cement and cortisomol paste were higher than that of zinc oxide-eugenol (ZOE) cement, and that no significant difference was observed between Ca3SiO5/CaCl2 composite cement and cortisomol paste. On antibacterial activity, Ca3SiO5/CaCl2 composite cements composed of varying amounts of CaCl2 (0-15%) exhibited similar levels of activity against E. coliasas calcium hydroxide cement, whereas cortisomol paste had little effect on E. colias. All these results suggested that Ca3SiO5/CaCl2 composite cement demonstrated good potential for root canal treatment applications.

Cytocompatibility of the ready-to-use bioceramic putty repair cement iRoot BP Plus with primary human osteoblasts.

AIM: To verify the in vitro cytocompatibility of iRoot BP Plus (iRoot) and to compare it with White ProRoot MTA (MTA). METHODOLOGY: Thirty-six human maxillary incisor root canals were prepared using a step-back flaring technique. The apical 3 mm was resected perpendicular to the long axis at the roots, and root-end cavities were prepared with the aid of an ultrasonic device plus a diamond retrotip with continuous irrigation using water, producing standardized preparations. After that, the root-end cavities were filled with iRoot or MTA, and each root was exposed to cell culture media for 24 or 48 h. Human osteoblast cells were exposed to the extracts thus obtained, and a multiparametric cell viability assay was performed, evaluating mitochondrial activity, membrane integrity and cell density. The results were analysed by one-way analysis of variance, complemented with the Duncan post-test (P < 0.05). RESULTS: Cells exposed to MTA revealed a cytocompatibility pattern similar to the untreated cells (negative control), at both experimental times (P > 0.05). iRoot, however, promoted a significantly poorer viability than MTA and the control, after 48 h of exposure (P < 0.001). Nevertheless, iRoot did not induce critical cytotoxic effects because cell viability remained higher than 70% of the control group in most tests performed. CONCLUSION: iRoot and MTA were biocompatible and did not induce critical cytotoxic effects.

The development of iron-free partially stabilized cement for use as dental root-end filling material.

AIM: To determine the effect of increasing the proportion of zinc on partially stabilized cement (PSC) produced using a one-step sol gel process. METHODOLOGY: A one-step sol-gel process of Portland cement-based PSC with Zn was synthesized by replacing iron nitrate. The crystalline phases of the PSC-Zn powder were analysed by using X-ray diffraction (XRD). The experimental groups [i.e., MTA, PSC-Fe (control), PSC with 1% Zn, PSC with 3% Zn, and PSC with 5% Zn] were immersed in simulated body fluid for 3 h, 1 and 3 days to evaluate the hydration product formation. The microstructure and surface morphology were analysed using scanning electron microscopy (SEM). Initial and final setting times of the materials were determined using an ASTM Vicat needle testing machine. To evaluate the cytotoxicity of PSC-Zn system, primary osteoblasts cell lines were used. RESULTS: The addition of increased weight percentages of Zn, resulted in a more unstable phase which favoured the formation of a monoclinic structure of C3 S with an increased hydration reaction of PSC and reduced setting time. The cytotoxicity testing of PSC with Zn revealed that the material was not toxic. CONCLUSIONS: The newly synthesized PSC-Zn material had short setting time and was biocompatible.

Biomimetic calcium-silicate cements support differentiation of human orofacial mesenchymal stem cells.

INTRODUCTION: Human orofacial bone mesenchymal stem cells (OFMSCs) from maxilla and mandible have robust osteogenic regenerative properties on the basis of our previous reports that demonstrate phenotypic and functional differences between jaw and axial bone mesenchymal stem cells in same individuals. Furthermore, a combination of OFMSCs with bioactive calcium-releasing cements can potentially improve OFMSC multilineage differentiation capacity, but biocompatibility of calcium-silicate cements with OFMSCs is still unclear. We tested the hypothesis that material extracts of calcium-releasing calcium-silicate cements support biomimetic microenvironment for survival and differentiation of human OFMSCs. METHODS: Two experimental calcium-silicate cements, (1) calcium-silicate mineral powder (wTC) containing dicalcium and tricalcium-silicate, calcium sulfate, and calcium chloride and (2) wTC doped with alpha-tricalcium phosphate (wTC-αTCP), were designed and prepared. Cement setting times were assessed by Gilmore needles, ability to release calcium and hydroxyl ions was assessed by potentiometric methods, and OFMSC attachment to calcium-silicate discs was assessed. Calcium-silicate material extracts were tested for ability to support OFMSC survival and in vitro/in vivo differentiation. RESULTS: Fewer OFMSCs attached to calcium-silicate discs relative to tissue culture plastic (P = .001). Extracts of calcium-silicate cements sustained OFMSC survival, maintained steady state levels of vascular cell adhesion molecule-1, alkaline phosphatase, and bone sialoprotein while up-regulating their respective gene transcripts. Adipogenic and in vivo bone regenerative capacities of OFMSCs were also unaffected by calcium-silicate extracts. CONCLUSIONS: Ion-releasing calcium-silicate cements support a biomimetic microenvironment conducive to survival and differentiation of OFMSCs. Combination of OFMSCs and calcium-silicate cement can potentially promote tissue regeneration in periapical bone defects.