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

Abstract

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.

Physical Properties, Antimicrobial Activity and In Vivo Tissue Response to Apexit Plus

“…Apexit Plus shows low or no cytotoxicity effect on L929 mouse fibroblasts [10] and human periodontal ligament fibroblasts [9]. Moreover, no genotoxicity was induced by Apexit Plus on an immortalized cell line derived from human pulp [38].…”

“…Apexit Plus (Ivoclar Vivadent, Schaan, Liechtenstein), a calcium hydroxide-based endodontic cement, has been launched in an attempt to provide a flawless seal at the apical foramen without damaging periodontal tissues. The base paste of Apexit Plus contains calcium hydroxide, calcium oxide, hydrated collophonium, highly dispersed silicon dioxide, and alkyl ester of phosphoric acid, while the activator paste contains disalicylate, bismuth hydroxide, bismuth carbonate associated to silicon dioxide, and phosphoric acid alkyl ester [4,9]. This calcium hydroxide-based sealer has caused slight cytotoxicity when cultured with L929 fibroblasts [10] and exerted good antimicrobial activity [11].…”

Biocompatibility of Root Canal Sealers: A Systematic Review of In Vitro and In Vivo Studies

“…In terms of the material setting condition, 23 studies evaluated root canal sealers in fresh or freshly mixed state, 15 in set condition with 24 h incubation, 15 in both freshly mixed and set conditions, and 20 in a set condition with other or multiple times of incubation. Concerning the cell models used for cell viability assessment (Table A2), several studies used cultures of human cells, namely: dental follicle-derived mesenchymal stem cells [23], tooth germderived stem cells [40], bone marrow-derived mesenchymal stem cells [49], gingival fibroblasts [31,[50][51][52][53][54][55][56], dental pulp stem cells [57], osteoblasts [23,41,46,[58][59][60][61], periodontal ligament cells [26,28,39,45,48,[62][63][64][65][66], human osteoblast-like cells (MG63) [38,42,67,68], cervical carcinoma cells or human cervical carcinoma cells (HeLa) cells [33,37] and THP-1 human monocytic cells [36]. Other cell…”

“…The methodological characteristics of the included in vitro studies are presented in Table A2 (Appendix B). Of the 73 studies, 18 used a direct contact testing method with sealers prepared either as fresh sample, disc, layer or cylindrical specimens [17,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38], while others used sealer specimens on inserts [39][40][41][42][43][44] or root models [45][46][47][48]. In terms of the material setting condition, 23 studies evaluated root canal sealers in fresh or freshly mixed state, 15 in set condition with 24 h incubation, 15 in both freshly mixed and set conditions, and 20 in a set condition with other or multiple times of incubation.…”

“…Regarding bioactive sealers, several studies reported no cytotoxic effect for BioRoot TM RCS (Septodont, Saint-Maur-des-Fossés, France) [24,62,63], mineral trioxide aggregate (MTA) sealers [21,26,70,71], iRoot ® (Innovative BioCeramix Inc., Vancouver, Canada) sealers [68,70,72], and Endosequence BC TM [51]. However, a cytotoxic effect of bioactive sealers was also reported in comparison with other materials, either similar-compared to epoxy resin-based [23,51,64,73,74] or calcium hydroxide-based [26] sealers-or lower compared to zinc oxide-eugenol-based [39,41,45,46,66,74,75], epoxy resin-based [23,39,40,49,52,61,66,[73][74][75][76], methacrylate resin-based [39,41], or other materials [67]. Some studies reported a higher cytotoxic effect of MTA Fillapex ® compared with epoxy resin-based sealers in set condition [23,40,51,57,61,66,…”