In vitro cytotoxicity evaluation of different pulp capping materials: a comparative study

Abstract

Direct pulp capping covers the exposed surface of the pulp to maintain its vitality and preserve its functional and biologic activity. The aim of the present study was to compare the biocompatibility effects of seven different pulp-capping materials in vitro: Dycal®, Calcicur®, Calcimol LC®, TheraCal LC®, ProRoot MTA®, MTA-Angelus®, and Biodentine®. Using the Transwell insert methodology by Alamar blue test, we evaluated the cytocompatibility of the above mentioned materials towards murine odontoblasts cells (MDPC-23) at three different times (24, 48, and 72 h). For additional control, the cell viability at 72 hours was also assessed by MTT assay. Morphological analysis of murine odontoblasts was assessed by Confocal Laser Scanning Microscope. The results indicate significantly different biocompatibility among materials with different composition. Biodentine® and mineral trioxide aggregate (MTA)-based products showed lower cytotoxicity, varying from calcium hydroxide-based materials, which exhibited higher cytotoxicity. Although our findings are limited to in vitro conditions, the observation that Biodentine® caused a cytotoxic effect similar to MTA suggests that it may be considered an alternative in pulp-capping treatment, as calcium hydroxide-based materials present higher cytotoxic effects.

Reactions of human dental pulp cells to capping agents in the presence or absence of bacterial exposure

“…In our study, change in the medium pH owing to the setting phase of the capping agents may partially contribute to the observed inhibitory effects. Consistent with previous studies, Dycal has an overall negative effect on HDP cells in this study, exhibiting cytotoxic effects and impeding growth and differentiation of pulp cells (8,29,31).…”

Cytotoxicity and biocompatibility of resin-free and resin-modified direct pulp capping materials: A state-of-the-art review

“…Although calcium hydroxide has been widely accepted in clinical practice, studies have shown it may be cytotoxic due to high alkalinity. It was reported that Calcicur (21% cell vitality in 3-day MTT test) was more cytotoxic than MTA or the negative control (26-35% cell vitality in the same test) 8) . Another study using rat subcutaneous tissue showed that calcium hydroxide, such as UltraCal XS, caused an intense inflammatory reaction and a coagulative necrosis at 7 days, but the inflammatory process was significantly reduced at 30 days 9) .…”

“…The hydrophilic matrix allows higher calcium and hydroxide release, which are very important in protecting pulp their ability to stimulate dentin formation and provide antibacterial action (high alkalinity), respectively 6,31,33) . Both TheraCal LC and resin-modified calcium hydroxide were shown to be more cytotoxic to murine odontoblasts cells and human dental pulp stem cells than resin-free calcium silicates, such as Biodentine, MTA Angelus, and ProRoot MTA, but they showed similar or lower cytotoxicity than Dycal (vitality with MTT test after 72 h: resin-modified materials: 14-15%, resin-free MTA 28-35%, Dycal 9%; number of vital cells with Alamar blue tests after 72 h: resin-modified materials: 33000-35000, resin-free MTA 333000-533000, Dycal 30000) 8,34) . However, this cytotoxicity might be due to the uncured monomers in the oxygen inhibition layer on the surface of TheraCal LC test samples during sample preparation in the laboratory (exposure to air/oxygen).…”

“…In one study, MTA exhibited no cytotoxicity to rat dental pulp cells after 72 h, whereas the two-paste calcium hydroxide (Dycal) killed almost all cells 24) . Another study also suggested that calcium silicates (ProRoot MTA, MTA-Angelus (Angelus, Londrina, PR, Brazil), Biodentine) were less cytotoxic to odontoblasts cells than two-paste calcium hydroxide (Dycal) and one-paste calcium hydroxide (Calcicur) 8) . An in vitro adult human dermal fibroblast cytotoxicity study showed that MTA materials (MTA-Angelus, Brasseler Endosequence Root Repair Putty) and resin-modified Ca(OH) 2 (Ultra-Blend Plus) had cytotoxicity levels statistically similar to the negative control, which was statistically less cytotoxic than the two-paste calcium hydroxide (Dycal) 20) .…”

“…Two-paste calcium hydroxide systems have been shown to be more toxic than the nonsetting one-paste calcium hydroxide systems, possibly due to the added toxicity of the additional components such as disalicylate, accelerator, and/or plasticizer. For example, in a 3-day MTT assay test with odontoblasts cells, two-paste calcium hydroxide (Dycal) demonstrated the lower cell vitality rate than other types of direct pulp capping materials, such as one-paste calcium hydroxide and MTA 8) . Dycal also showed significantly greater toxicity to human dental pulp cells than resin composites 13) .…”