A New Calcium Silicate-Based Root Canal Dressing: Physical and Chemical Properties, Cytotoxicity and Dentinal Tubule Penetration.

Natália Villa,Aline Teixeira Mendes,Vanessa Valgas Dos Santos,Pedro Henrique Marks Duarte,Ricardo Abreu Da Rosa,Ubirajara Maciel Da Costa,Jefferson Ricardo Pereira,Marcus Vinícius Reis Só

doi:10.1590/0103-6440202003376

Abstract

The aims of this study were to evaluate the physical and chemical properties, cytotoxicity and dentinal tubule penetration of a new calcium silicate-based root canal dressing. For pH and calcium ion release evaluation (1, 24, 72 and 168 h) were used a pH meter and colorimetric spectrophotometer, respectively. Radiopacity evaluation followed the ISO 6876:2012. Cytotoxicity was evaluated by the percentage of cell viability using MTT assay. Illustrative images of dentinal tubule penetration were obtained using confocal laser scanning microscopy (CLSM). Data from pH and calcium ion release were statistically analyzed by two-way analysis of variance and Tukey test. Radiopacity was analyzed using the Student t-test. The statistical tests for cytotoxicity results were the one-way analysis of variance and Tukey test. Both materials showed alkaline pH in all experimental times. The pH values for calcium hydroxide paste were higher than bioceramic paste at 1, 24, and 72 h (p<0.05). The calcium ion release of bioceramic was lower than the calcium hydroxide paste only at 24 h (p<0.05). The bioceramic was more radiopaque than the calcium hydroxide paste (p<0.05). Bioceramic paste presented a dose and time-dependent cytotoxic effect after MTT assay. CLSM images showed absence of tubule penetration for both pastes. The new calcium silicate-based canal dressing presented alkaline pH, high calcium release, and acceptable radiopacity. Bio C Temp showed a dose and time-dependent cytotoxic and absence of dentinal tubule penetration.

Highlights

The presence of microorganisms in the root canal system is directly related to the setting up of apical periodontitis [1]
This study aimed to evaluate pH, calcium ion release, radiopacity, and dentinal tubule penetration of a new
Cytotoxicity VERO Cell lines, from American Type Culture Collection (ATCC), were maintained in DMEM (Dulbecco’s Modified Eagle Medium, Sigma-Aldrich, Darmstadt, Germany) supplemented with 10% fetal bovine serum (Invitrogen) and antibiotics (1% penicillin-streptomycin-gentamycin; Invitrogen) in 75-cm2 culture flasks in a humidified atmosphere at 37°C and 5% CO2

Summary

Introduction

The presence of microorganisms in the root canal system is directly related to the setting up of apical periodontitis [1]. The chemical and mechanical preparation and root canal filling promote the reduction of this microbiota [2]. The presence of anatomical complexities may limit the access of instruments and irrigation solutions, which favors the permanence of microorganisms organized in biofilms [3]. Calcium hydroxide is the most commonly used medication. It has an alkaline pH (approximately 12.8), low solubility, and adequate flow [5]. This medication dissociates into calcium and hydroxyl ions; this mechanism is responsible for several biological properties, which are attributed to this medication, such as antimicrobial action, induction of hard tissue deposition and inhibition of tooth reabsorption [5]. An adequate radiopacity is essential for verifying the correct placement and maintenance of the root canal dressing into the root canal and is achieved by the addition of substances such as zinc oxide, iodoform, and barium sulfate [6]

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