Evaluation of Cytotoxicity of Calcium Silicate-based Mineral Trioxide Aggregate Sealers: A Systematic Review of In Vitro Studies.

AIM: This review aimed to evaluate the in vitro studies done with regard to the cytotoxicity associated with mineral trioxide aggregate (MTA)-based root canal sealers. BACKGROUND: Root canal sealers are used during endodontic treatment as fillers to seal the gaps between the canal gutta-percha cone and canal walls. It is necessary to understand the cytotoxicity of these materials on human-derived cells as these materials interact with human cells periapically. REVIEW RESULTS: Six in vitro studies were chosen for review. In these selected studies, along with MTA-based root canal sealers, other sealers were tested for cytotoxicity on human periodontal ligament (PDL) stem cells, human PDL fibroblasts, and human osteoblast cells. Regarding cytotoxicity, the studies were diverse, and most were based on 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide) (MTT) assay. In general, the studies suggested that root canal sealers cause mild to severe cytotoxic effects and that several factors influence this effect, such as material setting time, concentration, and duration of exposure. CONCLUSION: All studies in the review indicated that MTA. Fillapex must be used cautiously as it exhibited the highest cytotoxic effect compared to other MTA-based and non-MTA-based sealers. CLINICAL SIGNIFICANCE: Endodontic sealers do serve the purpose of bridging the gaps between the gutta-percha cone and the canal wall but knowing its biocompatibility becomes important as the material is extruded beyond the apical foramen where it comes in contact with the surrounding tissues. The effect of sealers on the surrounding tissues affects the healing and prognosis of the treatment.

Novel endodontic sealers induced satisfactory tissue response in mice.

OBJECTIVES: The aim of this study was to evaluate the subcutaneous response induced by Roeko Guttaflow2 (RG), Sealapex Xpress (SX), AH Plus (AHP) sealers. METHODS: 100 BALB/c mice received implants in the subcutaneous tissue with the tested materials (10 animals per period for each evaluated sealer) and were evaluated after different experimental periods (7, 21 and 63 days), in each animal was placed a tube, the control group was an empty tube. Histological analysis evaluated semi-quantitatively the inflammatory infiltration, collagen fiber formation and tissue thickness. In addition, immunohistochemistry was performed for interleukin-6 (IL-6). Data were statistically analyzed (α = 0.05). RESULTS: RG promoted a greater collagen fiber formation at 7 days and 63 days compared to the CG (p = 0.004) and AHP (p = 0.005) respectively, while at 21 days, the SX promoted a greater reaction (p = 0.021). For the tissue thickness, there was a greater reaction at 7 days with CG (p = 0.0156) and with RG at 63 days (p = 0.03). Regarding the inflammatory infiltrate, there was no difference at 7 days and 63 days (p = 0.5; p = 0.27), while at 21 days, a statistically difference was found between SX, CG (p = 0.04) and RG (p = 0.027). In addition, the presence of IL-6 was observed in almost all groups, with a more intense marking at 7days. SIGNIFICANCE: All cements evaluated presented a satisfactory tissue response, however, RG was the one that presented a more satisfactory tissue response.

Cytocompatibility of calcium silicate-based sealers in a three-dimensional cell culture model.

OBJECTIVES: The aim of the present study was to evaluate cytotoxic effects and cytokine production of calcium silicate-based sealers (EndoSeal, EndoSequence BC Sealer, and MTA Fillapex) using an in vitro root canal filling model and three-dimensional (3D) cell culture. AH Plus as a reference was compared to contemporary calcium silicate cements regarding cell viability and cytokine production. MATERIAL AND METHODS: Root canals of 30 human maxillary incisors were prepared using a single-file reciprocating technique. The samples were randomly distributed and canals filled with either AH Plus, EndoSeal, EndoSequence BC Sealer, and MTA Fillapex (n = 6). In the negative control group, the root canal remained unfilled. Sealers were placed into the canals along with a gutta-percha cone placed to working length. Balb/c 3T3 fibroblasts, cultured in a type I collagen 3D scaffold, were exposed to filling material and the respective root apex for 24 h. Cytocompatibility of the materials was evaluated using the methyl-thiazoldiphenyl-tetrazolium (MTT) assay. The production of IL-1ß, IL-6, and IL-8 was analyzed using enzyme-linked immunosorbent assay (ELISA). One-way analysis of variance was performed, and when the F-ratios were significant, data were compared by Duncan's multiple-range test. The alpha-type error was set at 0.05. RESULTS: EndoSeal, Endosequence BC Sealer and AH Plus showed cell viability that was similar to the negative control group (P > 0.05), while MTA Fillapex sealer was cytotoxic (P < 0.05). Varying production of IL-1ß, IL-6, and IL-8 was detected in all samples. CONCLUSIONS: In an in vitro root canal filling model with 3D cell culture, AH Plus, EndoSeal, and EndoSequence BC Sealer were cytocompatible. CLINICAL RELEVANCE: These results may suggest that AH Plus, EndoSeal and EndoSequence BC Sealer may achieve better biological response when compared to MTA Fillapex.

Cytotoxicity and gelatinolytic activity of a new silicon-based endodontic sealer.

PURPOSE: To compare the cytotoxicity, gelatinolytic activity, and protein levels (MMP-2 and MMP-9) produced by 3T3 fibroblasts cells after stimulation with GuttaFlow 2 and AH Plus. METHODS: 3T3 fibroblasts were incubated with elutes of GuttaFlow 2 and AH Plus for 24 h. The cytotoxicity of tested materials was determined using the MTT and the LDH assay. Supernatants of cell cultures incubated with sealers were collected to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Cell lysates were used to determine MMP-2 and MMP-9 protein levels by Western Blot. Data were analyzed using ANOVA and Tukey test (P<0.05). RESULTS: AH Plus showed significantly less cell viability (mitochondrial activity of cells) than GuttaFlow 2 (P<0.01). Moreover, GuttaFlow 2 was noncytotoxic, showing no statistically significant difference in LDH leakage levels compared to the control group (P>0.05). Specific characterization of MMPs demonstrated that GuttaFlow 2 seemed not to affect MMP-2 levels compared with the control group, while AH Plus had elevated gelatinolytic activity and protein levels of MMP-2 as confirmed by quantitative measurements. No detectable gelatinolytic activity or protein levels of MMP-9 (92 kDa) was observed in any tested group. CONCLUSIONS: GuttaFlow 2 did not showed cytotoxic effects and did not induce MMP-2 or MMP-9 expression.

In vitro cytotoxicity of guttaflow 2 on human gingival fibroblasts.

INTRODUCTION: The primary aim of this study was to evaluate the cytotoxic effects of GuttaFlow 2 (Coltène Whaledent, GmBH+Co KG, Langenau, Switzerland) on human gingival fibroblasts (HGFs). METHODS: Samples of the test materials GuttaFlow 2, mineral trioxide aggregate (MTA), AH Plus (Dentsply DeTrey, Konstanz, Germany), and RealSeal sealer (SybronEndo, Orange, CA) were fabricated in cylindrical nonreactive plastic tubes of 3-mm diameter and 2-mm height. Extracts of freshly mixed and set samples were prepared using the ratio of 0.5 cm(2)/mL, 1 cm(2)/mL, and 1.5 cm(2)/mL according to ISO 10993 series. The extracts were incubated with HGF cells for 24 and 72 hours. A cell counting kit-8 assay (Dojindo, Kumamoto, Japan) assay was used to examine cytotoxicity. The results were analyzed with the independent t test and 1-way analysis of variance test (P < .05). RESULTS: At all experimental conditions, the extracts of freshly mixed GuttaFlow 2 were nontoxic, whereas the extracts of freshly mixed and set AH Plus and RealSeal sealers were toxic to HGF cells (P < .05). The extracts of set GuttaFlow 2 were toxic at 72 hours (P < .05) and nontoxic at 24 hours. The extracts of freshly mixed MTA were nontoxic at both time points. For the extracts of set MTA, 1.5 cm(2)/mL was toxic at 72 hours and 1.5 cm(2)/mL and 1 cm(2)/mL were toxic at 24 hours (P < .05). CONCLUSIONS: Both GuttaFlow 2 and MTA evoked a less toxic response to HGF cells than AH Plus and RealSeal sealer.

In Vitro biocompatibility evaluation of a root canal filling material that expands on water sorption.

INTRODUCTION: CPoint is a polymeric endodontic point that takes advantage of water-induced, non-isotropic radial expansion to adapt to canal irregularities. This study evaluated the effects of CPoint on the viability and mineralization potential of odontoblast-like cells. METHODS: The biocompatibility of CPoint and commercially available gutta-percha points was evaluated by using a rat odontoblast-like cell line (MDPC-23). Cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and confocal laser scanning microscopy. The mineralization potential of MDPC-23 cells, in the presence of the root-filling materials, was evaluated by examining the changes in osteogenic gene marker expression (quantitative real-time polymerase chain reaction), alkaline phosphatase activity, alizarin red S assay, and transmission electron microscopy. RESULTS: CPoint showed higher initial cytotoxicity compared with gutta-percha and Teflon (P < .05), which became nonsignificant after 4 immersion cycles. Significant differences were also found between eluents from CPoint and gutta-percha at 1:1 concentration (P < .05) but not at 1:10 or 1:100 concentration. Both materials induced minimal apoptosis-induced alteration in plasma membrane permeability, as evidenced by flow cytometry and confocal laser scanning microscopy. Compared with the Teflon negative control, CPoint and gutta-percha groups showed up-regulation of most osteogenic gene markers except for dentin sialophosphoprotein, which was down-regulated. Alkaline phosphatase activity and alizarin red assay for CPoint and gutta-percha were both significantly higher than for Teflon but not significantly different from each other (P > .05). Transmission electron microscopy showed discrete nodular electron-dense mineralization foci in all 3 groups. CONCLUSIONS: The in vitro biocompatibility of CPoint is comparable to gutta-percha with minimal adverse effects on osteogenesis after elution of potentially toxic components.

Particulate matter neurotoxicity in culture is size-dependent.

Exposure to particulate matter (PM) air pollution produces inflammatory damage to the cardiopulmonary system. This toxicity appears to be inversely related to the size of the PM particles, with the ultrafine particle being more inflammatory than larger sizes. Exposure to PM has more recently been associated with neurotoxicity. This study examines if the size-dependent toxicity reported in cardiopulmonary systems also occurs in neural targets. For this study, PM ambient air was collected over a 2 week period from Sterling Forest State Park (Tuxedo, New York) and its particulates sized as Accumulation Mode, Fine (AMF) (>0.18-1µm) or Ultrafine (UF) (<0.18µm) samples. Rat dopaminergic neurons (N27) were exposed to suspensions of each PM fraction (0, 12.5, 25, 50µm/ml) and cell loss (as measured by Hoechst nuclear stain) measured after 24h exposure. Neuronal loss occurred in response to all tested concentrations of UF (>12.5µg/ml) but was only significant at the highest concentration of AMF (50µg/ml). To examine if PM size-dependent neurotoxicity was retained in the presence of other cell types, dissociated brain cultures of embryonic rat striatum were exposed to AMF (80µg/ml) or UF (8.0µg/ml). After 24h exposure, a significant increase of reactive nitrogen species (nitrite) and morphology suggestive of apoptosis occurred in both treatment groups. However, morphometric analysis of neuron specific enolase staining indicated that only the UF exposure produced significant neuronal loss, relative to controls. Together, these data suggest that the inverse relationship between size and toxicity reported in cardiopulmonary systems occurs in cultures of isolated dopaminergic neurons and in primary cultures of the rat striatum.

Effect of time of extraction on the biocompatibility of endodontic sealers with primary human fibroblasts

The aim of this work was to evaluate the effects of different times of extraction on the cytotoxicity of six representatives of different root canal sealer groups-Real Seal SE, AH Plus, GuttaFlow, Sealapex, Roth 801, and ThermaSeal Plus-with human gingival fibroblasts. The materials were prepared according to manufacturers' specifications, and were incubated in culture medium (DMEM) at 37ºC for 1, 7, 14, 21, and 28 days, with daily washing, to simulate periodontal ligament clearance. Human fibroblasts were exposed to the final extracts at 24 hours, and cell viability was determined by MTT assay, with exposure to unconditioned DMEM as a negative control. Statistical analysis comparing cytotoxicities at each exposure time was performed by ANOVA with Scheffé adjustment for multiple comparisons at a 95% confidence level. Results indicated that GuttaFlow was significantly less cytotoxic than all other sealers (p < 0.05) at 1 day of extraction. After 7 days of extraction, cell viability for GuttaFlow was significantly increased as compared with that of all groups except sealer AH Plus. At day 14, cytotoxicity of Sealapex was significantly higher than that of all other sealers (p < 0.05). At days 21 and 28, there were no significant differences in cytotoxicity among sealer groups. All materials presented some level of cytotoxicity to fibroblasts, while GuttaFlow was the least cytotoxic sealer tested. However, the cytotoxicity of all materials seemed to decrease similarly in a time-dependent manner.

Effect of time of extraction on the biocompatibility of endodontic sealers with primary human fibroblasts.

The aim of this work was to evaluate the effects of different times of extraction on the cytotoxicity of six representatives of different root canal sealer groups-Real Seal SE, AH Plus, GuttaFlow, Sealapex, Roth 801, and ThermaSeal Plus-with human gingival fibroblasts. The materials were prepared according to manufacturers' specifications, and were incubated in culture medium (DMEM) at 37ºC for 1, 7, 14, 21, and 28 days, with daily washing, to simulate periodontal ligament clearance. Human fibroblasts were exposed to the final extracts at 24 hours, and cell viability was determined by MTT assay, with exposure to unconditioned DMEM as a negative control. Statistical analysis comparing cytotoxicities at each exposure time was performed by ANOVA with Scheffé adjustment for multiple comparisons at a 95% confidence level. Results indicated that GuttaFlow was significantly less cytotoxic than all other sealers (p < 0.05) at 1 day of extraction. After 7 days of extraction, cell viability for GuttaFlow was significantly increased as compared with that of all groups except sealer AH Plus. At day 14, cytotoxicity of Sealapex was significantly higher than that of all other sealers (p < 0.05). At days 21 and 28, there were no significant differences in cytotoxicity among sealer groups. All materials presented some level of cytotoxicity to fibroblasts, while GuttaFlow was the least cytotoxic sealer tested. However, the cytotoxicity of all materials seemed to decrease similarly in a time-dependent manner.

Cytotoxicity evaluation of Gutta Flow and Endo Sequence BC sealers.

OBJECTIVE: This study evaluated the cytotoxicity of GuttaFlow and EndoSequence BC sealers and compared them with AH Plus and Tubli-Seal sealers. STUDY DESIGN: Samples (0.5 mg) of freshly mixed or set BC, GuttaFlow, AH Plus, and Tubli-Seal sealers were eluted with 300, 600, and 1,000 µL cell culture medium for 24 and 72 hours. L929 cells were seeded into 96-well plates at 3 × 10(4) cells/well and cultured with 100 µL eluate from each eluate group. Cells cultured only with culture medium served as control. After 24 hours' incubation, the cytotoxicity was evaluated by MTT assay. Cell viability was calculated as the percentage of the control group, and the results were analyzed with a one-way analysis of variance. RESULTS: For the freshly mixed sealer, cell viability in the AH Plus group was less than in all of the other 3 sealer groups. The Tubli-Seal sealer group had less cell viability than the EndoSequence BC and GuttaFlow sealer groups. For the set sealer, the Tubli-Seal and AH Plus groups had less cell viability than the EndoSequence BC and GuttaFlow sealer groups. There was no cell viability difference between the EndoSequence BC and GuttaFlow sealer groups in the either freshly mixed or set sealer group. CONCLUSIONS: The GuttaFlow and EndoSequence BC sealers have lower cytotoxicity than the AH Plus and Tubli-Seal sealers.

Evaluation of cytotoxicity of two root canal filling materials by MTT assay.

The aim of this study was to assess the cytotoxicity of two root filling materials GuttaFlow (GF) and gutta-percha (GP) on mouse fibroblasts cell line L-929. In this study there were four groups: GP and GF were considered as study groups and the other two were negative control groups. GP and GF were prepared according to manufacturer's instruction. L-929 fibroblast cells of mouse were passaged with trypsin (Merck, Germany) after elimination of freeze phase. Adequate trypsin was added to cells and they were prepared with 95% of cell vitality. After 24 h, 150,000 cells were put in each well. The cell and dimethyl methacrylate were used as negative and positive controls. Ten specimens from each group were brought into contact with the culture medium and were incubated under sterilised conditions 24 h later. The cytotoxicity of all samples was assessed by dimethylthiazol diphenyltetrazolium bromide test after 1 h, 24 h and 72 h. The results showed that cytotoxicity of GF was less than GP when assessed at 24 h and 72 h, but there was no significant difference at 1 h. In GF, the most and least cytotoxicity were observed at 24 h and 72 h while cytotoxicity of GP increased with time.

Cytotoxicity of RealSeal on human osteoblast-like MG63 cells.

INTRODUCTION: The purpose of this study was to compare the cytotoxicity of a new root canal filling material (RealSeal system) with epoxy resin-based root canal sealer (AH Plus) and gutta-percha by using human osteoblast-like MG63 cells. METHODS: Samples of each test material were fabricated in sterile cylindrical Teflon tubes of 4.4 mm diameter and 2 mm height. Extraction of specimens was carried out after setting in cell culture medium by using the ratio of 1.25 cm(2)/mL according to ISO 10993-5. Cytotoxicity was assessed by direct incubation of different extracts with MG63 cells at different time intervals. The dimethylthiazol diphenyltetrazolium bromide assay and flow cytometry were used to test the proliferation of MG63 cells. The results were analyzed with a Tukey test (alpha = 0.05). RESULTS: The gutta-percha was nontoxic to MG63 cells in vitro, whereas RealSeal core material showed initial cytotoxic effect on MG63 cells after 1 day of culture, which disappeared after 3 days of culture. The RealSeal sealer was significantly more cytotoxic than AH Plus (P < .05) within 3 days. Flow cytometry showed that cell proliferation in RealSeal sealer and AH Plus group was inhibited. CONCLUSIONS: The RealSeal sealer was significantly more toxic to MG63 cells than the AH Plus within 3 days, whereas RealSeal core material was similar with gutta-percha. Further research is required to evaluate the biocompatibility of RealSeal system comprehensively.

Comparision of biocompatibility and cytotoxicity of two new root canal sealers.

The aim of this study was to investigate the remote organ toxicity and connective tissue reaction of two new root canal sealers ("GuttaFlow(®)" and "EndoREZ(®)") and to compare them with zinc oxide eugenol sealer using biochemical and histopathological parameters. A total of 60 white albino Wistar rats were used in the study. 0.1ml of GuttaFlow(®), EndoREZ(®) or Kerr Pulp Canal Sealer(®) were administered subcutaneously into the mid-dorsal thoracic region of rats (15 in each group). Control rats were given saline only. Rats were decapitated after 24h, on day 7 and on day 30 of the experiment and tissue samples from lung, liver, kidney and skin were removed for the determination of malondialdehyde (MDA) and glutathione (GSH) levels. In parallel, tissues were also examined histologically. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and creatinine and blood urea nitrogen (BUN), concentrations (BUN) were measured to assess liver and kidney functions, respectively. Tumor necrosis factor (TNF) and lactate dehydrogenase (LDH) were also assayed in serum samples. No statistical differences were found among the control and EndoREZ(®), GuttaFlow(®) and Kerr Pulp Canal sealers regarding tissue MDA, GSH levels or serum parameters (p>0.05) at all time points examined. Both of the new root canal sealers showed good compatibility and acceptable tissue toxicity.

In vitro genotoxicity of root canal sealers.

AIM: To evaluate the effect of leakage on differences in genotoxicity of root canal sealers ex vivo according to their main components using two different cytogenetic assays. METHODOLOGY: Six materials of different composition (GuttaFlow, Epiphany, Diaket, IRM, SuperEBA and Hermetic) were tested on human peripheral blood lymphocytes using the comet assay and chromosomal aberration analysis. Prepared materials were eluted in physiological solution for 1 h, 1 day, 5 and 30 days. Thereafter cultures were treated with 8 microg, 4 microg and 2 microg of each sealer. Frequencies of chromatide and chromosome breaks and accentric fragments were determined. Comet assay was used to evaluate primary DNA damage by measuring tail length and tail intensity. Chi-square, Fisher's PLSD (Protected Least Significant Difference) and Kruskall-Wallis non parametric tests were used for statistical analysis. RESULTS: After 1-h elution only the highest dose of Diaket, Hermetic and SuperEBA significantly (P = 0.035, P = 0.048, P = 0.037 respectively) affected the measured cytogenetic parameters. The migration ability of DNA was more strongly affected than induction of chromosomal aberrations. After elutions longer than 24 h none of the tested sealers exhibited a genotoxic effect. CONCLUSION: Under the conditions used in the study all sealers had acceptable biocompatibility in terms of genotoxicity.

Cytotoxicity of endodontic materials over 6-weeks ex vivo.

AIM: To test the hypothesis that extending the time of a traditional ex vivo cytotoxicity test helps to identify trends in the behaviour of root core materials and sealers, which could ultimately aid in predicting their clinical safety and performance. METHODOLOGY: Endodontic sealers and core specimens were initially tested in direct contact with L929 fibroblasts for 72 h. Cell response was estimated by measuring cellular succinate dehydrogenase activity relative to Teflon controls. Cytotoxicity (% of more active cells) was reassessed after 1, 3, 4 and 6 weeks, with the specimens stored in a physiologically balanced salt-solution between tests. RESULTS: Distinct trends in cytotoxicity among both core materials and sealers were observed over the 6-week test. Four of the six sealers and two of the three core materials showed cell viabilities of <30% of Teflon after 6 weeks (>70% cytotoxicity). CONCLUSIONS: The current results suggest that some endodontic materials have an elevated biological risk for extended intervals.

Comparative study of the cytotoxic effect of Resilon against two cell lines.

Resilon is a new material that is a candidate to replace gutta-percha as a root filling material. This study evaluated the antiproliferative effect of Resilon and two commercially available gutta-percha points (Roeko, Dentsply). Two established cell lines (L929 and RPC-C2A) were used for the experiment. Cell survival fraction was estimated by the sulforhodamine-B assay, in reference to controls after 48-h exposure. Non-parametric tests (Kruskal-Wallis followed by Dunn's multiple comparisons) were used to evaluate the statistical significance of the results (alpha=0.05). Cytotoxicity in a descending order was: Resilon > Roeko gutta-percha > Dentsply gutta-percha. At 24-h exposure, no statistically significant differences (p>0.05) were observed between tested materials in both cell lines. At 48-h exposure, statistically significant differences (p<0.05) were found between Resilon and the other materials in the L929 cell line. In the RPC-C2A cell line Resilon was significantly more cytotoxic than Dentsply gutta-percha (p<0.05), but no statistically significant differences (p>0.05) were found between Resilon and Roeko gutta-percha. The cytotoxicity of Resilon increased significantly from 24 h to 48 h in both cell lines. Resilon points were more cytotoxic than gutta-percha points. The cytotoxicity was time dependent and increased after 48 h.

Comparative study of the cytotoxic effect of resilon against two cell lines

Resilon is a new material that is a candidate to replace gutta-percha as a root filling material. This study evaluated the antiproliferative effect of Resilon and two commercially available gutta-percha points (Roeko, Dentsply). Two established cell lines (L929 and RPC-C2A) were used for the experiment. Cell survival fraction was estimated by the sulforhodamine-B assay, in reference to controls after 48-h exposure. Non-parametric tests (Kruskal-Wallis followed by Dunn's multiple comparisons) were used to evaluate the statistical significance of the results (α=0.05). Cytotoxicity in a descending order was: Resilon > Roeko gutta-percha > Dentsply gutta-percha. At 24-h exposure, no statistically significant differences (p>0.05) were observed between tested materials in both cell lines. At 48-h exposure, statistically significant differences (p<0.05) were found between Resilon and the other materials in the L929 cell line. In the RPC-C2A cell line Resilon was significantly more cytotoxic than Dentsply gutta-percha (p<0.05), but no statistically significant differences (p>0.05) were found between Resilon and Roeko gutta-percha. The cytotoxicity of Resilon increased significantly from 24 h to 48 h in both cell lines. Resilon points were more cytotoxic than gutta-percha points. The cytotoxicity was time dependent and increased after 48 h.

Resilon é um material novo com potencial para substituir a guta-percha como material obturador radicular. Este estudo avaliou o efeito anti-proliferativo do Resilon e de duas marcas comerciais de pontas de guta-percha (Roeko e Dentsply). Para os fins deste estudo foram utilizadas duas linhagens celulares conhecidas (L929 e RPC-C2A). A fração de sobrevivência celular foi estimada pelo método colorimétrico de sulforodamina B comparado aos controles após exposição por 48 h. A significância estatística dos resultados (α=0,05) foi avaliada pelos testes não-paramétricos de Kruskal-Wallis e Dunn para comparações múltiplas. A citotoxicidade dos materiais em ordem decrescente foi: Resilon > guta-percha Roeko > guta-percha Dentsply. Após 24 h de exposição, não foram encontradas diferenças estatisticamente significantes (p>0,05) entre os materiais testados em ambas as linhagens celulares. Após 48 h, o Resilon apresentou um efeito citotóxico significantemente maior (p<0,05) em comparação aos outros dois materiais na linhagem celular L929. Na linhagem RPC-C2A, a citotoxicidade do Resilon foi significantemente maior (p<0,05) que a da guta-percha Dentsply, mas não houve diferenças significantes (p<0,05) entre Resilon e guta-percha Roeko. A citotoxicidade do Resilon aumentou significativamente de 24 para 48 h para ambas as linhagens celulares. As pontas de Resilon foram mais citotóxicas do que as pontas de guta-percha. A citotoxicidade foi tempo-dependente e aumentou após 48 h de exposição.

Short-term cytotoxicity assessment of components of the epiphany resin-percha obturating system by indirect and direct contact millipore filter assays.

The Epiphany Resin-Percha Obturating System was assessed for cytotoxicity, compared with gutta-percha and AH-Plus sealer. Specimen disks (Resilon, gutta-percha), filled glass rings (sealers), or imbibed cellulose disks (primer, thinning resin) were placed over Millipore filters in direct or indirect contact with HeLa cell monolayer, incubated for 2 hours, and stained with tetrazolium blue. Cytotoxicity was rated by the surrounding unstained zone: none (0 mm), mild (12 mm). Data were analyzed with one-way ANOVA and post hoc pairwise t tests. Unstained zones indicating moderate cytotoxicity were significantly larger (p < 0.05) for Epiphany primer than for thinning resin and for freshly mixed AH-Plus than for Epiphany sealer. Set sealers (24 and 48 hours), gutta-percha, and Resilon elicited noncytotoxic responses. In conclusion, cytotoxicity of set Epiphany sealer and Resilon was comparable with that of set AH-Plus and gutta-percha. Cytotoxicity of freshly mixed Epiphany sealer, primer, and thinning resin did not exceed that of freshly mixed AH-Plus.

Initial in vitro biological response to contemporary endodontic sealers.

The objective of this study was to evaluate the cytotoxicity of three endodontic sealers (AH Plus/Maillefer-Dentsply, Epiphany/Pentron, GuttaFlow, Coltene-Whaledent). Materials were mixed according to the manufacturer instructions and packed into Teflon molds (10 x 1 mm). For cytotoxicity testing (MTT method), the specimens were placed in contact with cultured cells, then evaluated at two subsequent time points (24 or 72 h). In addition to testing the mixed materials, 5 microl of primer liquid (GuttaFlow and Epiphany) and resin solvents (HEMA, ethanol, sterile water, or acetone) were added directly in culture for 24 and 72 h. The results showed that most materials pose significant cytotoxic risks and that cytotoxicity generally increased with time. At 72 h, GuttaFlow became significantly less toxic than AH Plus, Epiphany sealer, and Resilon. The current results support the need to continue to develop better endodontic sealers that combine the excellent sealing and bonding properties of resins with acceptable biological properties for endodontic applications.

Cytotoxicity of materials used in perforation repair tested using the V79 fibroblast cell line and the granulocyte-macrophage progenitor cells.

AIM: To compare the cytotoxicity of materials used to repair perforations using permanent V79 fibroblasts and murine granulocyte-macrophage progenitor cells (CFU-GM). METHODOLOGY: Set specimens from amalgam, glass-ionomer, SuperEBA, N-Rickert, MTA and gutta-percha were eluted with culture medium for 72 h and their cytotoxicities were assessed by incubating the extracts with V79 and bone marrow-derived progenitors for 24 h and 7 days, respectively. Cytotoxicity on V79 cells was judged using the total nucleic acid content (NAC), neutral red uptake (NRU) and reduction of the tetrazolium salt (MTT). The number of bone marrow CFU-GM colonies determined in clonal cultures stimulated with recombinant murine granulocyte-macrophage colony-stimulating factor was used to assess cytotoxicity to progenitor cells. Statistical analyses were conducted using the one-way analysis of variance and Tukey's test where appropriate. RESULTS: All materials were cytotoxic in both cell systems; however, CFU-GM was more sensitive to the extracts than V79 cells. A similar rank order of toxicity was observed in V79 cells using the NAC and the MTT assays: glass-ionomer > N-Rickert congruent with SuperEBA > gutta-percha > amalgam congruent with MTA (P < 0.05). In contrast, the NRU test exhibited a lower sensitivity to MTA, gutta-percha and amalgam extracts. In the clonal culture assay, the toxicity was less pronounced in the presence of gutta-percha, SuperEBA and MTA. Similar cellular responses were found by placing the set specimens directly in the clonal culture dishes. CONCLUSIONS: The sensitivity of toxicity depended on the choice of the endpoint and the cell-culture system. Nevertheless, MTA was ranked as the least cytotoxic cement in both cell systems.