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Aim: Previous studies have evaluated the pulpal responses to calcium silicate cements (CSCs) on normal dental pulp, but investigations on the effects of CSCs on inflamed pulp are limited. This study aimed to test the inflammatory response and odontogenic differentiation of inflamed rat dental pulp after direct pulp capping with CSCs. Methodology: Wistar rat molars pulps were exposed for 48 h to induce inflammation and then capped with ProRoot MTA (Dentsply), Biodentine (Septodont), RetroMTA (Bio MTA) and Dycal (Dentsply Caulk). The degree of pulpal inflammation and hard tissue formation was evaluated by histological analysis. Immunofluorescence staining for interleukin (IL)‐6, osteocalcin (OCN) and runt‐related transcription factor 2 (RUNX2) was also performed. Results: After 4 weeks, complete recovery from inflammation was evident in 22%, 37.5%, 10% and none of the ProRoot MTA, Biodentine, RetroMTA and Dycal samples, respectively. Heavy hard tissue deposition as a continuous hard tissue bridge was observed in 77.8%, 75%, 70% and 60% of the ProRoot MTA, Biodentine, RetroMTA and Dycal samples, respectively. IL‐6, OCN and RUNX2 were detected in all materials, mainly adjacent to areas of inflammation and reparative dentine formation. At one, two and 4 weeks, significant differences were not observed between the inflammation and hard tissue formation scores of the four material groups (p >.05). Conclusions: In this study, pulpal inflammation was still present in most specimens at 4 weeks after pulp capping and a significant number of samples showed incomplete and discontinuous dentine bridge formation. The results of this study suggest that initial inflammatory conditions of the pulp may risk the prognosis of teeth treated with CSCs. [ABSTRACT FROM AUTHOR]

Aim: Inflammatory‐regenerative cell interaction is believed to mediate hard tissue formation. This study aimed to investigate the interaction between human inflammatory monocytes with human regenerative fibroblasts after exposure to different calcium silicate materials. Methodology: Human monocytes were cultured on three materials, polystyrene (PS), mineral trioxide aggregates (MTA) and biodentine (BD), in the presence or absence of lipopolysaccharide (LPS). Half of the monocyte‐conditioned media (MoCM) of each group was used to analyse inflammatory cytokine secretion, namely TNF‐α, IL‐1β, IL‐1RA and IL‐6. The remaining MoCM was used to culture recipient fibroblasts, measuring the cell number (proliferation) and levels of alkaline phosphatase (differentiation) and lactic acid dehydrogenase (cytotoxicity). Results: In absence of LPS, MTA was associated with higher secretion of TNF‐α and lower secretion of IL‐1β, while BD triggered higher secretions of both cytokines when both materials were compared to control (PS). When LPS was added, higher levels of all analysed cytokines were observed in the PS and BD groups, whereas for the MTA group, only TNF‐α and IL‐6 were increased. Fibroblasts responded differently to the MoCM from the different groups, revealing significant increases in proliferation and differentiation capacities, particularly when cultured in CM from monocytes exposed to MTA. The morphological evaluation revealed different patterns of fibroblast shape and spread in the different MoCM groups. Conclusion: Calcium silicate materials modulate the monocyte inflammatory response, which subsequently induce differential effects on the recipient fibroblasts. MTA appears to promote the secretion of prodifferentiation signals from the monocytes, which are received by fibroblasts, promoting their proliferation and differentiation. The model represents a promising tool to evaluate the interaction of different cells in response to different materials. [ABSTRACT FROM AUTHOR]

Mineral trioxide aggregate ( MTA) is a bioactive endodontic cement ( BEC) mainly comprised of calcium and silicate elements. The cement was introduced by Torabinejad in the 1990s and has been approved by the Food and Drug Administration to be used in the United States in 1997. A number of new BECs have also been introduced to the market, including BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo- CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA without its drawbacks. In this article, the chemical composition and the application of MTA and other BECs for vital pulp therapy ( VPT), including indirect pulp cap, direct pulp cap, partial pulpotomy, pulpotomy and partial pulpectomy, have been reviewed and compared. Based on selected keywords, all papers regarding chemical composition and VPT applications of BECs had been reviewed. Most of the materials had calcium and silicate in their composition. Instead of referring to the cements based on their chemical compositions, we suggest the term 'bioactive endodontic cements ( BECs)', which seems more appropriate for these materials because, in spite of differences in their chemical compositions, bioactivity is a common property for all of them. Numerous articles were found regarding use of BECs as VPT agents for indirect and direct pulp capping, partial pulpotomy and cervical pulpotomy. Most of these investigations used MTA for VPT. In most studies, newly introduced materials have been compared to MTA. Some of the BECs have shown promising results; however, the number of their studies compared to investigations on MTA is limited. Most studies had several methodological shortcomings. Future investigations with rigorous methods and materials are needed. [ABSTRACT FROM AUTHOR]

Aim To compare the effect of mineral trioxide aggregate (MTA) and iRoot SP, a bioceramic root canal sealer, on the cell viability, hard tissue deposition capacity and odontogenic differentiation of human tooth germ stem cells ( hTGSCs). Methodology The dental materials MTA, iRoot SP and Dycal were packed into Teflon rings and placed on transwell inserts for toxicity evaluations by the MTS assay on days 3 and 7. Dycal was used as a positive control for the cell viability assay. Teflon rings were cocultured with hTGSCs, followed by the induction of odontogenic differentiation. The odontogenic differentiation of hTGSCs and biomineralization ability of the materials were evaluated by analysing the mRNA expression levels of dentine sialophosphoprotein (DSPP) and collagen type 1A (COL1A) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase (ALP) activity and visualization of calcium deposits by von Kossa staining. Results MTA and iRoot SP exhibited no cytotoxicity, but Dycal caused cytotoxicity ( P < 0.05) of almost all of the cells after 7 days. MTA significantly stimulated ( P < 0.05) the odontogenic differentiation of hTGSCs compared with iRoot SP. MTA and iRoot SP increased ( P < 0.05) the mRNA levels of COL1A and DSPP mRNA compared with noninduced hTGSCs, which served as a negative control (NC). iRoot SP, however, significantly decreased ( P < 0.05) COL1A and DSPP mRNA expression levels compared with the PC. Conclusion MTA and iRoot SP induced hTGSC differentiation into odontoblast-like cells, but MTA might provide more inductive potential and hard tissue deposition compared with iRoot SP. [ABSTRACT FROM AUTHOR]

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. 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 < 0.05) in fluid filtration after the first 2 weeks. No statistically significant differences were observed between FMTA and AH Plus at all analysis times. At short times (24, 48-h), no statistically significant differences were found between the experimental cements and AH Plus. At long-term evaluations (1, 3, 6 months), FMTA and AH Plus sealed significantly better ( P < 0.05) than MTA. FMTA was associated with lower fluid filtration rates, and the seal was stable from 48 h to 6 months, thus proving the most effective material. Scanning electron microscopy with energy dispersive analysis of root sections filled with calcium silicate sealers revealed the formation of a blend layer of gutta-percha and cement consequent to the warm gutta-percha condensation technique. Scanning electron microscopy with energy dispersive analysis of 24-h-stored disks identified a Ca-rich coating on the outer surface consisting of globular particles (calcium hydroxide and calcium carbonate), and a deeper internal Ca- and Si-rich region consisting of needle-like ettringite crystals and round formations of calcium silicate hydrate gel. Conclusion Fluoride-doped MTA demonstrated stable sealing during a period of up to 6 months and significantly better than conventional calcium silicate MTA cements and comparable to AH Plus. The study supports the suitability of calcium silicate MTA cements as sealers in association with warm gutta-percha for root filling. [ABSTRACT FROM AUTHOR]

Camilleri J. Evaluation of the physical properties of an endodontic Portland cement incorporating alternative radiopacifiers used as root-end filling material. International Endodontic Journal, 43, 231–240, 2010. Aim To investigate the physical and chemical properties of Portland cement (PC) loaded with alternative radiopacifying materials for use as root-end filling materials in a mineral trioxide aggregate (MTA)-like system. Methodology Portland cement loaded with barium sulphate, gold and silver/tin alloy was mixed with water, and the physical and chemical properties of the hydrated cements were evaluated. MTA and intermediate restorative material (IRM) were used as controls. The radiopacity was compared to the equivalent thickness of aluminium, and the setting time of the cements was assessed using an indentation technique. The compressive strength and the stress–strain relationship were determined at 28 days. The stress–strain relationship was determined by monitoring the strain generated when the cement was subjected to compressive load. In addition, the pH was determined in water and simulated body fluid for a period of 28 days. Results The radiopacity of the cements using alternative radiopacifiers was comparable to MTA ( P > 0.05). IRM demonstrated a higher radiopacity than all the materials tested ( P < 0.05). All the cements with the exception of IRM exhibited an alkaline pH and had an extended setting time when compared to IRM. MTA had a longer setting time than the PC ( P < 0.001), and its setting time was similar to the gold-loaded cement ( P = 0.159). The addition of a radiopacifier retarded the setting time ( P < 0.001) but did not have any effect on the compressive strength as all loaded cements had comparable strength to PC ( P > 0.05). IRM was the weakest cement tested ( P < 0.001). The cement loaded with gold radiopacifier had comparable strength to MTA ( P = 1). The stress–strain relationship was linear for all the cements with IRM generating more strain on loading. Conclusions Within the parameters set in this study, bismuth oxide in MTA can be replaced by gold or silver/tin alloy. The physical, mechanical and chemical properties of the cement replaced with alternative radiopacifiers were similar and comparable to ProRoot MTA. [ABSTRACT FROM AUTHOR]