Biocompatibility Of Mineral Trioxide Aggregate Research Articles

Biocompatibility of mineral trioxide aggregate and biodentine as root-end filling materials: an in vivo study

This study evaluated the biocompatibility of mineral trioxide aggregate (MTA) and Biodentine (BD) as root-end filling materials. Six mongrel dogs were divided into two equal groups according to the evaluation period; group A: one month and group B: three months. Three premolars of the same quadrant in each arch were used, summing up 36 teeth (6 teeth/dog). These teeth were randomly subdivided into three subgroups according to the root-end filling material used: MTA, BD and no root-end filling material (control). Endodontic access cavities were performed for induction of periapical pathosis. After the infection period, root canal instrumentation and obturation were accomplished. One day after root canal procedures, root-end surgery was performed. Surgical access was achieved and the root-end was resected approximately 3 mm above the apex. Root-end cavity was prepared ultrasonically and filled with the tested materials. All samples were evaluated by radiography and histopathology (Inflammation and new hard tissue formation). Data were collected and subjected to statistical analysis. In group A, MTA subgroup exhibited significant higher mean inflammatory score than BD subgroup (P < 0.05) while no significant difference was recorded between MTA and BD subgroups in group B (P > 0.05). Regarding mean mineralization score, there was no significant difference between all subgroups in both groups A and B (P > 0.05). Biodentine exhibited favorable biocompatibility in the initial stage of healing than MTA and comparable biomineralization. Clinical relevance: Biodentine could be considered as an acceptable alternative to MTA in peri-radicular surgeries.

Biocompatibility of NeoMTA Plus\xae versus MTA Angelus as delayed furcation perforation repair materials in a dog model

BackgroundThe biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials.MethodsPulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value < 0.05 was considered significant.ResultsIn all subgroups, the control group exhibited the highest number of inflammatory cell count, followed by MTA Angelus group and the least inflammatory cell count was shown by NeoMTA Plus® group. There was a significant difference in the inflammatory cell count between the NeoMTA Plus® and MTA Angelus after one week (P < 0.05) while no significant differences were recorded between them after one month and three months (P > 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair.ConclusionNeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months.

Push-Out Bond Strength of MTA as Root Canal Sealer: A Systematic Review

Introduction: Endodontic treatment includes different phases like controlling the growth of microorganism, thorough cleaning and shaping and fluid-tight seal. Sealer plays an important role in Root Canal Treatment (RCT). Sealer fills the space between filling material and dentin. Sealer also acts as a lubricant. Sealer has ability to fill the spaces and prevent microleakege from the root canal. Mineral Trioxide Aggregate (MTA) is a calcium silicate based sealer which has high radiopacity, low solubility and good antibacterial activity. Aim: To evaluate push-out bond strength of MTA as a root canal sealer. Materials and Methods: Studies which were published in English, studies with different years of publication were included. Studies which includes bond strength of MTA as Endodontic Sealer to dentinal wall were also included. Studies used in this review were in-vitro studies and clinical trials. Studies showing tissue toxicity, biocompatibility of MTA were excluded. Also, case reports and in-vivo studies were excluded. All abstracts as well as full texts were studied. PubMed/Medline, Web of Science and Scopus were used for this study. Keywords used were “root canal sealer”, “push-out bond strength”, “MTA”. Total 18 articles were collected. But only five articles fulfilled the inclusion and exclusion criteria. So only five articles were included in this study and discussed in detail. Results: According to the results, of articles which were chosen for this study stated that MTA can be used as an endodontic sealer though it shows lesser push-out bond strength when compared with different newer sealers. Conclusion: In this systematic review, only one in-vitro study showed that Proroot MTA used as root canal sealer exhibits high push-out bond strength than other sealers like MTA Fillapex sealer and AH plus sealer. While MTA Fillapex show lesser push-out bond strength in comparison with other sealers like Proroot MTA sealer, AH plus, Endo CPM sealer. So this systematic review partially fulfills the hypothesis as it gives a utility of Proroot MTA as a root canal sealer.

Cytotoxicity Evaluation of Three Biocompatible and Bioactive Retrofilling Materials Using Periodontal Ligament Stem Cells: An In-Vitro Study

This study aimed to: evaluate the biocompatibility of Mineral Trioxide Aggregate (MTA) versus Biodentine and Retro MTA extracts at three observation periods (24h, 48h, and 72h) using MTT-Essay.Methods: 72 wells in three culture insert plates were used in this study. MTA, Biodentine and Retro MTA cements were evaluated in a fresh state. Cells at passage four of human periodontal ligament cells were included in this study. After cells preparation and culturing, an extract of the three tested materials was prepared and cultured with the complete media in addition to 1×104 cells were implanted into each well 24 h earlier and incubated in a stem cell incubator. MTT assay was used to evaluate in vitro cytotoxicity, calculated the viable cells by hundred percent using ELISA system and the inverted light microscope used to reassure their confluence. After three different storage times (24h, 48h, and 72h) evaluation of cell viability was done after exposure to the material extract. Results: MTA and Biodentine cement showed no statistically significant differences in all the observation periods. But Retro MTA cement resulted in a statistically significant difference in all the observation periods but none of them below the cut level. All the materials extract resulted in a statistically significant increase in cytotoxicity at 24h and then decrease at 48h and finally a little increase in cytotoxicity at 72h. Conclusions: All the tested materials showed low cytotoxicity and are comparable to the old standard MTA.

Enhancing Effect of Elastinlike Polypeptide-based Matrix on the Physical Properties of Mineral Trioxide Aggregate

IntroductionElastinlike polypeptide (ELP) is 1 of the genetically engineered, protein-based polypeptides, which offers outstanding advantages such as superior biocompatibility, long-term stability, elasticity, and cost-effectiveness. This study aimed to investigate the effect of an ELP-based matrix on the physical properties and biocompatibility of mineral trioxide aggregate (MTA). MethodsThe 2 types of ELPs were synthesized and mixed with the MTA powder in various liquid-to-powder ratios. The physical properties including compressive strength, microhardness and setting time, washout resistance, and biocompatibility were investigated for the ELP-incorporated MTA. The microstructure of the MTA was also analyzed using scanning electron microscopy and Fourier-transform infrared spectroscopy. ResultsThe ELP-based matrix enhanced the physical properties of MTA, including the compressive strength, microhardness, and washout resistance of MTA. The ELP incorporation showed no negative effect on biocompatibility. However, ELPs prolonged the setting time of MTA. ConclusionsThese results suggested that the addition of the ELP-based matrix to MTA enhanced the physical properties without negatively affecting the chemical structure and biocompatibility of MTA. Further investigation is warranted to overcome a clinical challenge associated with the extended setting time caused by the addition of ELP.

Response of periodontium to mineral trioxide aggregate and Biodentine: a pilot histological study on humans.

The aim of this study was to investigate for the first time the histological response of human periodontium to mineral trioxide aggregate (MTA) and Biodentine. Six patients scheduled for implant full-arch rehabilitation were randomly assigned to one of the two test groups: MTA or Biodentine treatment. For each patient, two teeth scheduled for strategic extraction were randomly assigned either to the test or to the control treatment. A lateral perforation was drilled on the root and either repaired with MTA/Biodentine or filled with gutta-percha(control). Three months later, the teeth were extracted along with the coronal third of the alveolar bone and a portion of gingival tissue, while performing implant placement, and processed for histological analysis. Biodentine resulted in less extrusion into the periodontal environment. All the materials showed good biocompatibility. A new mineralized cementum-like tissue incorporating periodontal fibres was visible in all cases treated with MTA. A small amount of new mineralized tissue was found in two Biodentine cases but not in control cases. Biodentine resulted in less damage to the periodontal ligament. Bioactivity and biocompatibility of MTA were confirmed in human models. Biodentine proved to be biocompatible, but it seems not to induce cementum regeneration.

Superfast Set, Strong and Less Degradable Mineral Trioxide Aggregate Cement.

Purpose Despite the good sealing ability and biocompatibility of mineral trioxide aggregate (MTA), its slow setting, high degradation, and weakness limit its use in surgical endodontics and high stress-bearing areas. This study aimed to develop two new liquids to control these drawbacks. They were prepared from calcium chloride, fumed silica, and hydroxyapatite or calcium phosphate and coded “H” and “P,” respectively. Methods Portland cement, Grey ProRoot® MTA, and white ProRoot MTA were mixed with distilled water (control) or liquid “H” or “P.” The pH, setting time, degradation rate, leachant/precipitate' composition, compressive strength, and morphology were assessed. Results Both liquids maintained MTA's high alkalinity and reduced the setting time by 1-2 orders of magnitude. Both liquids, H in particular, significantly reduced the degradation rate of Grey ProRoot and White ProRoot MTA®. Calcite has been identified as the main phase of the leachant or precipitate formed during the cement's degradation. Calcium hydroxide or hydroxyapatite was also identified with Grey ProRoot MTA mixed with H liquid. These liquids also significantly increased the compressive strength with no statistical differences between them; this was associated with the production of dense, consolidated structures. Conclusions The modified MTA could be used in surgical endodontics and high stress-bearing areas.

Effect of the plant-based hemostatic agent Ankaferd Blood Stopper® on the biocompatibility of mineral trioxide aggregate.

BackgroundDue to the detrimental effect of blood contamination on the physico-chemical properties of mineral trioxide aggregate (MTA), obtaining an effective hemostasis in the surgical crypt during apical surgery is of paramount importance. The purpose of this in vivo study was to analyze the effect of Ankaferd Blood Stopper® (ABS) contamination on the biocompatibility of MTA.MethodsForty of 56 Wistar–Albino rats were divided randomly and equally into two groups (MTA and MTA-ABS) according to whether or not a hemostatic agent was used. The remaining 16 rats were designated as the control group. Rats in the experimental groups received freshly mixed MTA-Angelus in polyethylene tubes, which were inserted into monocortical bore holes created in their tibias. In the MTA-ABS group only, 0.5 mL of ABS solution was administered topically on the defect sites followed by implantation of MTA tubes. Inflammation, foreign-body reaction (FBR), necrosis, fibrosis, and new bone formation (NBF) were studied 7, 30, 60, and 90 days after implantation.ResultsOn day7, statistically significant differences were found in tissue reactions with regard to NBF and necrosis (p = 0.044 and p = 0.024, respectively), the latter being observed in 40 % of the samples only in the MTA-ABS group. Slight inflammation in all groups was confined to day-7 only. Mild necrosis was present in the MTA-ABS group only on day-7. Severity of the foreign body reaction and fibrosis was limited. New bone formation increased gradually over time in all groups, reaching a maximum on day-90.ConclusionsMTA and ABS-contaminated MTA are equally biocompatible. ABS does not impair the properties of MTA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12903-016-0302-0) contains supplementary material, which is available to authorized users.

The effects of various mixing solutions on the biocompatibility of mineral trioxide aggregate

To evaluate the effects of various mixing solutions on the biocompatibility of mineral trioxide aggregate (MTA). Human alveolar osteoblasts (hOAs) were incubated with eluates of 24h-set cement discs of MTA mixed with sterile H2 O, 3% sodium hypochlorite (NaOCl), 4% articaine (Ultracain(®) D-S), 0.9% NaCl, Ringer's solution or citrated blood, respectively. The cell proliferation in the presence of eluates was assessed by real-time cell analysis, and the expression of genes associated with proliferation (histone H3, HistH3), inflammation (interleukin-6, IL-6, matrix metalloproteinases 1 and 3, MMP1, MMP3) or apoptosis (caspase 3, Casp3) was analysed by qPCR after 24 and 72h. The ultrastructure of cells grown on cement discs was visualized by scanning electron microscopy (SEM), whilst actin cytoskeleton was monitored by fluorescence staining in the presence of eluates after 7 and 14days. A repeated-measure analysis was performed, and P-values were adjusted by Tukey. Whilst articaine-MTA sustained hOA proliferation patterns similar to H2 O-MTA, NaOCl-MTA reduced hOA proliferation and significantly increased the expression of MMP1 and MMP3. The addition of H2 O and articaine modulated the gene expression of Casp3 or Hist3H3. The use of NaCl, Ringer and blood induced mRNA levels comparable to matched controls. With the exception of NaOCl-MTA, SEM and FM revealed regular hOA morphology for all mixing solutions. NaOCl was highly cytotoxic for hOAs whilst all other mixing solutions can be considered as convenient biocompatible mixing solutions as alternatives to H2 O for clinical use.

Assessment of the biocompatibility of mineral trioxide aggregate, bioaggregate, and biodentine in the subcutaneous tissue of rats.

The objective of this study was to evaluate the tissue inflammation caused by three endodontic repair materials. The materials included micro mega-mineral trioxide aggregate (MM-MTA), bioaggregate (BA), and biodentine (BD), which were implanted into the subcutaneous tissue of rats. The tissue samples for histological examination were prepared. The infiltration of lymphocytes and macrophages into the tissue was examined to assess the inflammatory response. Lymphocyte infiltration: A significant increase was detected in the MM-MTA and BA groups on the 7th and 14th days as compared with the control (7th day P=0.0001, 14th day P=0.0176). There was no difference between the groups on the 45th day (P=0.1730). Lymphocyte infiltration had decreased over time in all groups. Macrophage infiltration: There was a significant increase by the 7th day in the test groups as compared to the control group (P=0.007). However, there was no difference between the experimental groups on the 14th (P=0.2708) and 45th (P=0.1291) days. While MM-MTA and BA showed a similar biocompatibility, BD was more biocompatible than MM-MTA and BA in the 1 st week of the experiment. However, there was no difference between the materials at the end of the 45th day. MM-MTA, BA, and BD can be considered suitable endodontic repair materials.

Biocompatibility of Mineral Trioxide Aggregate Mixed with Hydration Accelerators

IntroductionThe aim of this study was to evaluate the biocompatibility of mineral trioxide aggregate mixed with selective hydration accelerators such as calcium chloride (CaCl2), citric acid (CA), and calcium lactate gluconate solution (CLG). MethodsInductively coupled plasma-atomic emission spectrometry analysis was used to measure calcium ions in the extracts of test materials. The 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide assay was performed using MG-63 cells to examine the cytotoxicity of the test materials. The surface of each sample and the growth pattern of the attached cells were observed using scanning electron microscopy (SEM). ResultsMTA mixed with 10 wt% CaCl2 and MTA mixed with 43.4 wt% CLG released a higher amount of calcium ions than the other groups. The 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide assay revealed that the cell viability of MTA mixed with 0.1 wt% CA was significantly higher than pure MTA on 7-day extract (P < .05). MTA mixed with 43.4 wt% CLG showed significantly higher cell viability than the other groups on 1-day extract (P < .05). MTA mixed with 10 wt% CaCl2 in all groups showed the lowest cell viability at all time points (P < .05). Under SEM, elongated and confluent cells were observed in all samples except in samples of MTA mixed with 10 wt% CaCl2. ConclusionsMTA mixed with 0.1 wt% CA showed good biocompatibility. MTA mixed with 43.4 wt% CLG showed favorable biocompatibility on 1 day. MTA mixed with 10 wt% CaCl2 in all groups showed the lowest cell viability at every time point and poor cell attachment under SEM.

Response of mice connective tissue to three different endodontic materials

The aim of this study was to evaluate the biocompatibility of mineral trioxide aggregate (MTA) Bio and Portland cement (PC) and compare with those of ProRoot MTA. Polyethylene tubes were filled with materials and placed into dorsal subcutaneous connective tissue of Wistar albino rats. After 7, 30, and 60 days after the surgical procedure, the implants with the surrounding tissue were removed. Tissue samples were subjected to histological processing, and sections were stained with hematoxylin and eosin. Sections were evaluated for the intensity of inflammation, predominant cell type, presence of fibrous capsule and granulation tissue. Data were submitted to Kruskal-Wallis test at a significant level of P ≤ 0.05. No statistical differences were observed at any evaluated condition among tested materials (P > 0.05). Statistically significant differences were observed between mean inflammatory scores, cell types and granulation tissue of the same material in different experimental periods (P < 0.05). Can be concluded that biocompatibility of MTA bio and PC were comparable with that of ProRoot MTA.

Osseous reaction to implantation of two endodontic cements: Mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)

Aim: The aim of the present in vivo study was to determine bone tissue reaction to calcium enriched mixture (CEM) and mineral trioxide aggregate (MTA) using a rat femur model. Study Design: Sixty-three rats were selected and randomly divided into three groups of 21 each [experimental groups (n=15), control (n=6)]. Implantation cavities were prepared in each femoral bone and randomly filled with the biomaterials only in the experimental groups. The animals in three groups were sacrificed 1, 4, and 8 weeks postoperatively. Histologic evaluations comprising inflammation severity and new bone formation were blindly made on H&E-stained decalcified 6-µm sections. Results: At 1, 4, and 8 weeks after implantation number of inflammatory cells had decreased in the CEM, MTA and control groups, respectively, with no statistically significant differences. Conversely, new bone formation had increased in all the experimental and control groups, without statistically significant differences. Conclusion: The results suggest that biocompatibility of MTA, as gold standard, and CEM cement as a new endodontic biomaterial are comparable Key words:Endodontics, MTA,CEM, osseous reaction.

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

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

Influence of accelerated setting using plaster of Paris addition on long term properties of Portland cement based dental material

The dental material, mineral trioxide aggregate (MTA) is a modified Portland cement (PC) with added bismuth oxide (Bi2O3) radiopacifying powder. The reported biocompatibility of MTA has led to its widespread use as a root filling material. However, MTA has a long initial setting time of 2 h 45 min (M. Torabinejad, C. U. Hong and F. McDonald: J. Endod., 1995, 21, 349–352), which is undesirable for its application, for both patient and dentist. This study showed that the initial setting time can be decreased to several minutes by adding 30 wt-% plaster of Paris (PoP) and also investigated the long term effects of PoP additions on the compressive strength (CS), porosity and the solubility (in terms of calcium ion release) of an MTA-like PC system. Additions of 30 wt-% to MTA-like cements led to an almost complete loss of CS after 12 months of storage in an aqueous environment. This could be explained first by PoP interfering with the PC setting reaction and second by the appearance of a gypsum structure within the cement. As excess PoP was no longer consumed in the setting reaction, it is likely to have formed a more soluble gypsum structure, which was then dissolved, causing the porosity to more than double from 25 wt-% at 10 days to 56 wt-% after 12 months. PoP addition should therefore be restricted to ∼10 wt-%, which caused no changes in strength or porosity, the latter used as an indicator of cement sealing ability.

Effect of selected accelerants on setting time and biocompatibility of mineral trioxide aggregate (MTA)

Various additives have been suggested to be used with mineral trioxide aggregate (MTA) to improve its handling characteristics. The purpose of this study was to evaluate the effects of various additives on setting time and cell attachment on gray MTA (GMTA). Single-rooted caries-free teeth were split, and dentin disks with class I cavity were made and filled with test and control materials. Setting time was measured using Gilmore apparatus. Mouse MC3T3-E1 osteoblasts and L929 mouse fibroblasts were grown on dentin and GMTA disks. Cell attachment was examined under fluorescent microscope. Adding KY liquid, CaCl(2), and NaOCl to GMTA improved the handling properties and decreased setting time. Osteoblasts and fibroblasts attached and spread on GMTA mixed with additives in a manner similar to GMTA mixed with water. The various additives could be possible substitutes to water to decrease MTA setting time. MTA is biocompatible when mixed with the various additives.

In Vitro Comparison of the Biocompatibility of Mineral Trioxide Aggregate, 4META/MMA-TBB Resin, and Intermediate Restorative Material as Root-end–Filling Materials

This study compared the effects of three root-end-filling materials: mineral trioxide aggregate (MTA), 4-META/MMA-TBB resin (Super-bond), and intermediate restorative material (IRM) on osteoblast adhesion, proliferation, and matrix formation. MC3T3-E1 cells were inoculated on set material specimens, and the number of cells adhered to each material was assessed at 6 hours and at 3 days of incubation by using Hoechst 33258 staining under a fluorescence microscope. Furthermore, on day 21 of culture, areas in contact with each material surface were observed at light and electron microscopic levels. Cultured cells that adhered to MTA and Super-bond proliferated significantly between 6 hours and 3 days of culture. In addition, on day 21, they produced a thick matrix layer directly on the material surfaces. In contrast, the number of cells that adhered to IRM significantly decreased with time. These cells appeared round in shape, and no matrix formation was found. These results suggest that MTA and Super-bond have good biocompatibility and allow hard-tissue forming cells to create a matrix layer, which might enhance apical tissue regeneration.

Mineral trioxide aggregate: a review of the constituents and biological properties of the material

This paper reviews the literature on the constituents and biocompatibility of mineral trioxide aggregate (MTA). A Medline search was conducted. The first publication on the material was in November 1993. The Medline search identified 206 papers published from November 1993 to August 2005. Specific searches on constituents and biocompatibility of mineral trioxide aggregate, however, yielded few publications. Initially all abstracts were read to identify which fitted one of the two categories required for this review, constituents or biocompatibility. Based on this assessment and a review of the papers, 13 were included in the constituent category and 53 in the biocompatibility category. Relatively few articles addressed the constituents of MTA, whilst cytological evaluation was the most widely used biocompatibility test.

Assessment of biocompatibility of mineral trioxide aggregate with an improved rabbit ear chamber

Assessment of biocompatibility of mineral trioxide aggregate with an improved rabbit ear chamber

The chemical constitution and biocompatibility of accelerated Portland cement for endodontic use

To evaluate the biocompatibility of mineral trioxide aggregate and accelerated Portland cement and their eluants by assessing cell metabolic function and proliferation. The chemical constitution of grey and white Portland cement, grey and white mineral trioxide aggregate (MTA) and accelerated Portland cement produced by excluding gypsum from the manufacturing process (Aalborg White) was determined using both energy dispersive analysis with X-ray and X-ray diffraction analysis. Biocompatibility of the materials was assessed using a direct test method where cell proliferation was measured quantitatively using Alamar Blue dye and an indirect test method where cells were grown on material elutions and cell proliferation was assessed using methyltetrazolium assay as recommended by the International standard guidelines, ISO 10993-Part 5 for in vitro testing. The chemical constitution of all the materials tested was similar. Indirect studies of the eluants showed an increase in cell activity after 24 h compared with the control in culture medium (P<0.05). Direct cell contact with the cements resulted in a fall in cell viability for all time points studied (P<0.001). Biocompatibility testing of the cement eluants showed the presence of no toxic leachables from the grey or white MTA, and that the addition of bismuth oxide to the accelerated Portland cement did not interfere with biocompatibility. The new accelerated Portland cement showed similar results. Cell growth was poor when seeded in direct contact with the test cements. However, the elution made up of calcium hydroxide produced during the hydration reaction was shown to induce cell proliferation.