Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study

Odontology, Dec 2017

The aim of the study was to compare ex vivo the toxic effects of six root canal sealers immediately after mixing or setting on human periodontal ligament fibroblasts (HPdLF). Freshly mixed (I group) or set (allowed to dry for 24 h) (II group) specimens of AH Plus Jet (AH), Apexit Plus (AP), MTA Fillapex (FL), GuttaFlow (GF), MetaSEAL Soft (META), and Tubli-Seal (TS) were prepared. HPdLF were exposed for 24 h to the specimens. 3-(4,5-dimethylthiazolo-2-yl)-2,5-diphenyltetrazolium bromide assay was used to examine the effect of the root canal sealers on mitochondrial metabolic activity. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide staining followed by flow cytometry was used to identify the effects of the materials on cell apoptosis/necrosis. Statistical analyses were performed by one-way ANOVA followed by post hoc tests, and significance was determined at P < 0.05. Most materials from the two groups reduced the viability of the cultured cells compared with the control group (P < 0.05). Statistical analysis showed significant differences in HPdLF viability between the individual materials in each group (P < 0.001). AH and AP induced a significant increase in the percentage of apoptotic cells, while TS, FL, and META elevated the proportion of necrotic cells compared with other materials and the controls (p < 0.05). The cytotoxic effects of the tested root canal sealers (both fresh and set) on HPdLF varied. Both forms of sealers were able to cause toxic effects by inducing apoptosis and necrosis in HPdLF. The cytotoxicity of FL, META, TS was mainly associated with necrosis, while AH and AP with apoptosis.

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Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study

Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study Grzegorz Szczurko 0 1 2 4 Małgorzata Pawińska 0 1 2 4 Elżbieta Łuczaj‑Cepowicz 0 1 2 4 Anna Kierklo 0 1 2 4 Grażyna Marczuk‑Kolada 0 1 2 4 Adam Hołownia 0 1 2 4 0 Department of Dentistry Propaedeutics, Medical University of Białystok , J. Waszyngton Street 15A, 15-274 Białystok , Poland 1 Department of Pediatric Dentistry, Medical University of Białystok , J. Waszyngton Street 15A, 15-274 Białystok , Poland 2 Department of Integrated Dentistry, Medical University of Białystok , M. Skłodowska-Curie Street 24A, 15-276 Białystok , Poland 3 Grzegorz Szczurko 4 Department of Clinical Pharmacology, Medical University of Białystok , J. Waszyngton Street 15A, 15-274 Białystok , Poland The aim of the study was to compare ex vivo the toxic effects of six root canal sealers immediately after mixing or setting on human periodontal ligament fibroblasts (HPdLF). Freshly mixed (I group) or set (allowed to dry for 24 h) (II group) specimens of AH Plus Jet (AH), Apexit Plus (AP), MTA Fillapex (FL), GuttaFlow (GF), MetaSEAL Soft (META), and Tubli-Seal (TS) were prepared. HPdLF were exposed for 24 h to the specimens. 3-(4,5-dimethylthiazolo-2-yl)-2,5-diphenyltetrazolium bromide assay was used to examine the effect of the root canal sealers on mitochondrial metabolic activity. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide staining followed by flow cytometry was used to identify the effects of the materials on cell apoptosis/necrosis. Statistical analyses were performed by one-way ANOVA followed by post hoc tests, and significance was determined at P < 0.05. Most materials from the two groups reduced the viability of the cultured cells compared with the control group (P < 0.05). Statistical analysis showed significant differences in HPdLF viability between the individual materials in each group (P < 0.001). AH and AP induced a significant increase in the percentage of apoptotic cells, while TS, FL, and META elevated the proportion of necrotic cells compared with other materials and the controls (p < 0.05). The cytotoxic effects of the tested root canal sealers (both fresh and set) on HPdLF varied. Both forms of sealers were able to cause toxic effects by inducing apoptosis and necrosis in HPdLF. The cytotoxicity of FL, META, TS was mainly associated with necrosis, while AH and AP with apoptosis. Cytotoxicity; Flow cytometry; MTT; Periodontal ligament fibroblasts; Root canal sealer Introduction Tight sealing of the root canal system requires the use of gutta-percha as the basic material and sealer. The role of root canal sealer is to bind the primary filling material with the canal wall, seal the gaps between gutta-percha and dentin, as well as to facilitate the introduction of cones into the canal space by ensuring slipperiness [ 1 ]. Several groups of sealers, which are classified based on their chemical composition, are currently available. Calcium hydroxide sealers- Apexit Plus (AP) (IvoclarVivadent, Schaan, Lichtenstein), zinc oxide eugenol sealers- Tubli-Seal (TS) (Kerr, Salerno, Italy) and epoxy resin-based sealers- AH Plus (AH) (Dentsply De Trey, Konstanz, Germany) belong to earlier generation formulations. There has been a continuous search for an ideal formulation that would meet all of Grossman’s clinical criteria [ 2 ]. New sealers, which contain methacrylic resinsMetaSEAL Soft (META) (Sun Medical, Tokyo, Japan), silicone compounds- GuttaFlow (GF) (Coltene/Whaledent, Langenau, Germany), or mineral trioxide aggregatesMTA Fillapex (FL) (Angelus, Londrina,Brasil) have been introduced. Although obturative materials should be present only in the root canal, methods using heated, plasticized guttapercha, which allow sealer penetration into periapical tissues [ 3 ], particularly under favorable anatomical conditions (e.g. wide apical foramen), are increasingly used. Even despite maintaining adequate caution during obturation, there still is a risk of penetration of sealer components and the products of its degradation into periapical tissues. This can elicit local inflammatory response, thus contributing to failure in treatment despite appropriate root canal debridement and disinfection [ 4 ]. Due to a long-term contact with periapical tissues, root canal filling materials should exhibit not only excellent physical and chemical properties but also biocompatibility [ 5, 6 ]. Toxic formulations can damage tissues or hinder healing of inflamed periapical structures [7]. Before introduction into clinical use, all materials must be assessed for their potential toxicity in vitro. Although this type of study does not fully reflect the behavior of these formulations in living organisms, it provides data on their potential toxic effects on cells and tissues. The advantages of such experiments include a relatively simple research technique, repeatability, the possibility of simultaneous evaluation (...truncated)


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Grzegorz Szczurko, Małgorzata Pawińska, Elżbieta Łuczaj-Cepowicz, Anna Kierklo, Grażyna Marczuk-Kolada, Adam Hołownia. Effect of root canal sealers on human periodontal ligament fibroblast viability: ex vivo study, Odontology, 2017, pp. 1-12, DOI: 10.1007/s10266-017-0329-y