title: Effects of root-end filling materials and eugenol on mitochondrial dehydrogenase activity and cytotoxicity to human periodontal ligament fibroblasts.
abstract: Various root-end filling materials have been used to prevent the entry of root-canal pathogens into periapical regions. Five root-end filling materials were compared regarding the cytotoxicity, apoptosis, and mitochondrial dehydrogenase (MDH) activities of human periodontal ligament (PDL) fibroblasts, with the use of a novel transwell culture system. Exposure to IRM (a ZnO eugenol-based intermediate restorative material), a 2-ethoxybenzoic acid cement (Super EBA), and amalgam for 3 days inhibited the MDH activity of PDL fibroblasts as indicated by decrease in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction by 97%, 95%, and 51%, respectively. Evident suppression of MTT reduction by amalgam and glass ionomer cement (GIC) was noted after 5 days of exposure, with 73% and 46% of inhibition, respectively. Mineral trioxide aggregates (MTA) showed little effect on MDH activity. IRM and Super EBA were cytotoxic to PDL fibroblasts as indicated by a trypan blue dye exclusion technique. GIC and amalgam showed mild cytotoxicity. IRM, GIC, and amalgam further induced apoptosis of PDL cells, as revealed by the presence of sub-G0/G1 DNA content in flow cytometric histogram. Twenty-four-hour exposure to IRM and Super EBA elevated the MDH activities to 156% and 117%, correspondingly, of that of control. Eugenol, a phenolic ingredient in Super EBA and IRM, also increases MDH activity of PDL fibroblasts by 45% and 51%, at concentrations of 0.5 and 1 mM. However, at concentrations higher than 0.5 mM, eugenol decreased the number of viable PDL fibroblasts. These results suggest that MTA is a biocompatible root-end filling material, followed by self-curing Fuji II GIC and amalgam. IRM and Super EBA ingredients induced marked cytotoxicity and transiently stimulate MDH activities, which is possibly due to their content of eugenol and induction of cellular adaptive response.
authors.affiliation: Department of Dentistry, National Taiwan University Hospital, College of Medicine.
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Lin
authors.forename: Yi-Jane
authors.initials: YJ
authors.lastname: Chen
authors.forename: Yuan-Ling
authors.initials: YL
authors.lastname: Lee
authors.forename: Juo-Song
authors.initials: JS
authors.lastname: Wang
authors.forename: Mei-Chi
authors.initials: MC
authors.lastname: Chang
authors.forename: Wan-Hong
authors.initials: WH
authors.lastname: Lan
authors.forename: Hsiao-Hwa
authors.initials: HH
authors.lastname: Chang
authors.forename: William Ming-Wei
authors.initials: WM
authors.lastname: Chao
authors.forename: Tseng-Fang
authors.initials: TF
authors.lastname: Tai
authors.forename: Mon-Ying
authors.initials: MY
authors.lastname: Lee
authors.forename: Bor-Ru
authors.initials: BR
authors.lastname: Lin
authors.forename: Jiiang-Huei
authors.initials: JH
authors.lastname: Jeng
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000032:analysis / Q000096:biosynthesis; D005054:Eugenol / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects*; D005434:Flow Cytometry; D005881:Gingiva / Q000166:cytology; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism*; D010513:Periodontal Ligament / Q000166:cytology* / Q000187:drug effects; D012387:Root Canal Filling Materials / Q000494:pharmacology*; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D012387:Root Canal Filling Materials; D013778:Tetrazolium Salts; D013844:Thiazoles; D005054:Eugenol; D004247:DNA; D010088:Oxidoreductases; D000469:Alkaline Phosphatase; C022616:thiazolyl blue