• The Journal of Advanced Prosthodontics
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• v.12 no.2
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• pp.89-99
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• 2020

PURPOSE. The effects of four different self-adhesive resin cement materials on cell viability and apoptosis after direct and indirect exposure were evaluated using different cell culture techniques. MATERIALS AND METHODS. Self-adhesive cements were applied to NIH/3T3 mouse fibroblasts by the extract test method, cell culture inserts, and dentin barrier test method. After exposure periods of 24 h and 72 h, the cytotoxicity of these self-adhesive materials was evaluated using the MTT assay (viability) and the Annexin-V-FITC/PI staining (apoptosis). RESULTS. The lowest cell viability was found in cells exposed to BeautiCem SA for 24 h in the extract test method. Cell viability was reduced to 70.6% compared to negative controls. After the 72 h exposure period, viability rate of cell cultures exposed to BeautiCem SA decreased more than 2- fold (29.5%) while cells exposed to RelyX U200 showed the highest viability rate of 71.4%. In the dentin barrier test method, BeautiCem SA induced the highest number of cells in apoptosis after a 24 h exposure (4.1%). Panavia SA Cement Plus was the material that caused the lowest number of cells in apoptosis (1.5%). CONCLUSION. The used self-adhesive cements have showed different cytotoxic effects based on the evaluation method. As exposure time increased, the materials showed more cytotoxic and apoptotic effects. BeautiCem SA caused significantly more severe cytotoxic and apoptotic effects than other cements tested. Moreover, cements other than BeautiCem SA have caused necrotic cell death rather than apoptotic cell death.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.111-118
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• 2010

Purpose: The aim of this study was to investigate whether vitrification in the cryopreservation of periodontal ligament (PDL) cells could be useful for tooth banking. Methods: In step 1, primary cultured human PDL cells were cryopreserved in 100% conventional cryopreservation media and 100% vitrification media (ESF40 media) in different temperatures for 2 weeks. In step 2, a series of modified vitrification formulae named T1 (75% vitrification media + 25% F-media), T2 (50% vitrification media + 50% F-media) and T3 (25% vitrification media + 75% F-media) were used to store PDL cells for 2 weeks and 4 weeks in liquid nitrogen. MTT assay was performed to examine the viability of PDL cells. Results: Maximum cell viability was achieved in cells stored in 100% conventional cryopreservation media at $-196^{\circ}C$ (positive control group) in step 1. Compared to the positive control group, viability of the cells stored in 100% vitrification media was very low as 10% in all test conditions. In step 2, as the percentage of vitrification media decreased, the cell viability increased in cells stored for 2 weeks. In 4-week storage of cells in step 2, higher cell viability was observed in the T2 group than the other vitrification formulae while the positive control group had the highest viability. There was no statistically significant difference in the cell viability of 2-week and 4-week stored cells in the T2 group. Conclusions: These observations indicate 100% vitrification media is not successful in PDL cell cryopreservation. Conventional cryopreservation media is currently the most appropriate media type for this purpose while T2 media would be interesting to test for long-term storage of PDL cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.4
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• pp.291-301
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• 2015

This study compared the in vitro cell viability and differentiation potentials of human deciduous dental pulp cells (DPCs) on mineral trioxide aggregate (MTA)-like products (ProRoot MTA, RetroMTA and Endocem Zr). The experimental materials were prepared as circular discs, which were used to test the effects of the materials on the viability of human DPCs when placed in direct and indirect contact. Furthermore, the pH of the extracted materials was recorded, and their effect on cell differentiation potential was evaluated by evaluating the alkaline phosphatase (ALP) activity and Alizarin Red S staining of DPCs incubated with the test materials. In direct contact, the cell viability of human DPCs was higher with ProRoot MTA and RetroMTA than with Endocem Zr. However, when in indirect contact, the cell viability of human DPCs was generally higher in Endocem Zr than in ProRoot MTA and Retro MTA. With respect to pH, the alkalinity was lower for Endocem Zr than for the other test materials. The ALP activities of the cells were not enhanced by any of the experimental materials. Alizarin Red S staining of the tested human DPCs revealed that their differentiation potential was lower than for cells incubated with osteogenic induction medium. While there were differences in the responses of the human DPCs to the test materials, all displayed degrees of cytotoxicity and were unable to enhance either the viability or differentiation of human DPCs. However, Endocem Zr exhibited better cell viability and was less alkaline than the other test materials.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.4.1-4.10
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• 2014

Objectives Effects of nanoparticles including zinc oxide nanoparticles, titanium oxide nanoparticles, and their mixtures on skin corrosion and irritation were investigated by using in vitro 3D human skin models ($KeraSkin^{TM}$) and the results were compared to those of an in vivo animal test. Methods Skin models were incubated with nanoparticles for a definite time period and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide method. Skin corrosion and irritation were identified by the decreased viability based on the pre-determined threshold. Results Cell viability after exposure to nanomaterial was not decreased to the pre-determined threshold level, which was 15% after 60 minutes exposure in corrosion test and 50% after 45 minutes exposure in the irritation test. IL-$1{\alpha}$ release and histopathological findings support the results of cell viability test. In vivo test using rabbits also showed non-corrosive and non-irritant results. Conclusions The findings provide the evidence that zinc oxide nanoparticles, titanium oxide nanoparticles and their mixture are 'non corrosive' and 'non-irritant' to the human skin by a globally harmonized classification system. In vivo test using animals can be replaced by an alternative in vitro test.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.324-328
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• 2008

One hundred-eighty extracts of soil collected from ginseng (Panax ginseng C.A. Meyer) fields were subjected to lettuce germination test, electrolyte leakage, cell viability and antioxidant enzyme activity test. Regardless of various cultivation periods, there was no significant difference in soil pH, the content of organic matter and available phosphate in ginseng fields. Based on lettuce seed germination test, six soil extracts showing inhibition of germination and/or seedling growth were selected for further study. Selected soil extracts markedly inhibited cell viability of ginseng cultured cells but leakage of electrolytes were not affected by the treatment. Enzyme activity of superoxide dimutase in ginseng cultured cells was not affected by the treatment with the soil extracts. However, those of peroxidase and catalase were significantly inhibited by the treatment with soil extracts which showed inhibition of lettuce seed germination and seedling growth.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.295-303
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• 2003

Physiological cellular activities responses to cadmium (Cd) exposure in green algae with several reductases activities and viability of the cell were examined. The cell division of green algae, Selenastrum capricornutum treated with 5ppm was significantly decreased than that of normal algae. The mean cell number of normal algal culture was as twice much as than that of algae at 6 days after Cd treatment. The cellular viability of algae was analysed by flow-cytometry with fluorescent dye after esterase reaction on cell membrane. The 85.35% of cellular viability of normal culture was decreased to 34.35% when algae was treated with 5 ppm of Cd at 6 days after treatment. It was considered that those method of flow-cytometry is useful tool for toxicity test on micro-organisms in the respect of identifying cellular viability. Also, the activities of both glutathione peroxidase (GPX) and ascorbate peroxidase (APX), which are indirectly react against oxidative stress through reduction of glutathione by Cd were significantly increased with 25%. It is considered that both GPX and APX are involved in the metabolic pathway of Cd -detoxification with similar portion in Selenasturm capricornutum.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.473-478
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• 2010

Objectives: This study was performed to investigate the biocompatibility of newly introduced Bioaggregate on human pulp and PDL cells. Materials and Methods: Cells were collected from human pulp and PDL tissue of extracted premolars. Cell culture plate was coated either with Bioaggregate or white MTA, then the same number of cells were poured to cell culture dishes. Cell attachment and growth was examined under a phase microscope after 1,3 and 7 days of seeding. Cell viability was measured and the data was analyzed using Student t-test and one way ANOVA. Results: Both types of cells used in this study were well attached and grew healthy on Bioaggregate and MTA coated culture dishes. No cell inhibition zone was observed in Bioaggregate group. There was no statistical difference of viable cells between bioaggreagte and MTA groups. Conclusions: Bioaggregate appeared to be biocompatible compared with white MTA on human pulp and PDL cells.

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.80-86
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• 2014

Purpose: Current common method of cytotoxicity evaluation for elastomeric impression materials use animal based cell lines, which the clinical relevance has been often questioned. Hence, the purpose of this study was to examine the difference in results with both human based and animal based fibroblast cell line. Materials and Methods: Three types of fibroblast cells were used in this study; conventional mouse fibroblasts of L929, human gingival fibroblasts (HGF-1), and immortalized human oral fibrobalsts (hTERT-hNOF). Test on extract and test by direct contact using different commercially available elastomeric impression materials were carried out according to the international standards. Result: There was significant difference in cell viability between types of fibroblasts cell used, where HGF-1 showed highest cell viability and L929 the lowest. Conclusion: Within the limitation of this study, careful consideration must be given when selecting the cells and interpreting the results for cytotoxicity evaluation of elastomeric impression materials, where use of human based cell lines such as hTERT-hNOF would be appropriate for both ease of cytotoxicity test and clinical relevance.

• Journal of Korean Dental Science
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• v.14 no.2
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• pp.51-60
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• 2021

Purpose: Measuring viability of a three-dimensional in vitro organotypic human oral tissue model has been suggested as an alternative test method to the oral mucosa irritation test of oral care products. The aim of this study was to investigate the production of two different cytokines using organotypic human oral tissue model following exposure to chemicals that are commonly used in oral care products. Materials and Methods: The organotypic human oral tissues were exposed to ethanol, sodium lauryl sulphate or hydrogen peroxide for 90 minutes. Following exposure, interleukin (IL)-1α and IL-8 productions were assessed and correlated with cell viability testing as well as histology of the organotypic human oral tissues. Result: High levels of IL-8 were released from organotypic human oral tissues in all of the test and control groups without any significant differences between them. In contrast, differences were found in IL-1α release between the test and control groups. Additionally, the trend of IL-1α release corresponded to the phenotypes observed in histological analysis while different trend existed between IL-1α release and cell viability. Conclusion: The study concluded the non-specific release of IL-8 for the assessment of oral care product chemicals' toxicity, while potential of measuring IL-1α cytokine level as the possible alternative test method.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.122-131
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• 1995

Five human cancer cell lines (HeLa S3, Hep 3B, KATO III, Hs 683, HeLa MR) and one human normal cell line (WI-38) were examined cell viability, northern blot analysis, western blot analysis, and in situ hybridization for the expression $O_{6}$ -methylguanine-DNAmethyltransferase (MGMT), which can repair $O_{6}$ -methylguanine produced in DNA by alkylating agents. In cell viability test, the lethal sensitivities of each strain against anti-tumor drug N,N-bis(2-chloroethyl)- N-nitrosourea (BCNU) were counted, and both BCNU treated and untreated cell extracts were examined for their MGMT inducibility by RNA dot blot analysis. Cell lines did not show MGMT induction by BCNU pretreatment. Tlle MGMT activity was assayed by measuring the $^3$H radioactivity transferred from the substrate DNA containing [methyl-$^3$H)-O$_{6}$ -methylguanine to acceptor molecules in the cell extracts. Extracts from the majority of tumor strains and normal cells contained substantial MGMT activity of varying degree, while the known Mer$^{[-10]}$ cell (lacked or severely depleted in MGMT activity) Hela MR, and Hs 683 (proved to be Mer$^{[-10]}$ ) were much more sensitive to BCNU than the rest of tumor strains, as measured by cell viability test. Overall results above, KATO III showed the highest expression level of MGMT among the strains examined. Furthermore, with all the tumor and normal strains tested, a good correlation was observed between MGMT expression and cellular resistance to BCNU. The varying levels of expression of MGMT in human cancer cells found in this study should provide a molecular basis for MGMT expression among tumor strains from different tissue origin, the information of antitumor agents selection for chemotherapy of cancers.