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)