http://www.biofilling.com/article/7_1Mineral.pdf

Mineral trioxide aggregate: a comprehensive literature review--part II: leakage and biocompatibility investigations.

Calcium hydroxide has been included within several materials and antimicrobial formulations that are used in a number of treatment modalities in endodontics. These include, inter-appointment intracanal medicaments, pulp-capping agents and root canal sealers. Calcium hydroxide formulations are also used during treatment of root perforations, root fractures and root resorption and have a role in dental traumatology, for example, following tooth avulsion and luxation injuries. The purpose of this paper is to review the properties and clinical applications of calcium hydroxide in endodontics and dental traumatology including its antibacterial activity, antifungal activity, effect on bacterial biofilms, the synergism between calcium hydroxide and other agents, its effects on the properties of dentine, the diffusion of hydroxyl ions through dentine and its toxicity. Pure calcium hydroxide paste has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. Its main actions are achieved through the ionic dissociation of Ca2+ and OH- ions and their effect on vital tissues, the induction of hard-tissue deposition and the antibacterial properties. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. It has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also an effective anti-endotoxin agent. However, its effect on microbial biofilms is controversial.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2591.2011.01886.x

Properties and applications of calcium hydroxide in endodontics and dental traumatology.

Chelating agents were introduced into endodontics as an aid for the preparation of narrow and calcified root canals in 1957 by Nygaard-Ostby. A liquid solution of ethylenediaminetetraacetic acid (EDTA) was thought to chemically soften the root canal dentine and dissolve the smear layer, as well as to increase dentine permeability. Although the efficacy of EDTA preparations in softening root dentine has been debated, chelator preparations have regained popularity recently. Almost all manufacturers of nickel-titanium instruments recommend their use as a lubricant during rotary root canal preparation. Additionally, a final irrigation of the root canal with 15-17% EDTA solutions to dissolve the smear layer is recommended in many textbooks. This paper reviews the relevant literature on chelating agents, presents an overview of the chemical and pharmacological properties of EDTA preparations and makes recommendations for their clinical use.

Chelating agents in root canal treatment: mode of action and indications for their use.

Camilleri J, Pitt Ford TR. Mineral trioxide aggregate: a review of the constituents and biological properties of the material. International Endodontic Journal, 39, 747–754, 2006. This paper reviews the literature on the constituents and biocompatibility of mineral trioxide aggregate (MTA). A Medline search was conducted. The first publication on the material was in November 1993. The Medline search identified 206 papers published from November 1993 to August 2005. Specific searches on constituents and biocompatibility of mineral trioxide aggregate, however, yielded few publications. Initially all abstracts were read to identify which fitted one of the two categories required for this review, constituents or biocompatibility. Based on this assessment and a review of the papers, 13 were included in the constituent category and 53 in the biocompatibility category. Relatively few articles addressed the constituents of MTA, whilst cytological evaluation was the most widely used biocompatibility test.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2591.2006.01135.x

Mineral trioxide aggregate: a review of the constituents and biological properties of the material.

REVIEW ARTICLE: Calcium hydroxide has been used in endodontology for many years. The aim of this paper is to review the various formulations of calcium hydroxide that have been described, with specific reference to the vehicle used to carry the compound. The requirements for a vehicle are described, and ex vivo and in vivo studies reviewed. Vehicles can be classified into aqueous, viscous and oily, the clinical properties of calcium hydroxide changing depending on the vehicle. The review also describes the use of various active components that have been added to calcium hydroxide, including antimicrobial and anti-inflammatory agents. This review will help clinicians to make informed judgements about which formulations of calcium hydroxide should be used for specific endodontic procedures.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2591.1999.00232.x

Calcium hydroxide pastes: classification and clinical indications.

The cytotoxicity of three calcium hydroxide-containing root canal sealers (Sealapex, CRCS and Apexit) was tested by using L929 and BHK 21/C13 cells. After setting for 24 h, the sealers were covered with cell suspension. Cytotoxicity was determined by a quantitative technique at 24 h, 48 h and 72 h. All the sealers were found to be cytotoxic. Sealapex showed the highest cytotoxicity, causing a significant decrease in cell density. CRCS was less toxic than Sealapex and more toxic than Apexit. Apexit proved to be the least toxic material.

In vitro evaluation of the cytotoxicity of calcium hydroxide-based root canal sealers

Antiproliferative effect of mineral trioxide aggregate, zinc oxide-eugenol cement, and glass-ionomer cement against three fibroblastic cell lines.

The cytotoxicity of three resin-based root canal sealers (AH26, AH-Plus, Topseal) was evaluated in vitro. The experiments included two cell lines, L929 mouse skin fibroblasts and RPC-C2A rat pulp cells. The cytotoxicity was assessed by sulforodamine B (SRB) colorimetric assay and hemocytometer viable cell counting after 24- and 48-h exposure. AH26 had a severe cytotoxic effect whilst Topseal and AH-Plus showed a markedly lower toxic influence on the cells during the experimental period.

Cytotoxicity of three resin-based root canal sealers: an in vitro evaluation

The purpose of the present in vitro study was to compare the cytotoxic effect of two commercially available brands of mineral trioxide cement (ProRoot MTA and MTA Angelus), modified zinc oxide-eugenol cement (SuperEBA) and resin-modified glass ionomer cement (Vitrebond) using rat pulp cells (RPC-C2A) and human lung fibroblasts (MRC-5). The cells were cultured in typical culture conditions and exposed to the tested materials by adaptation of insert wells. The cytotoxic effect was recorded at two observation periods (24 and 72 h) by using a colorimetric assay of tetrazolium reduction (XTT method) in reference to controls. Overall, the degree of cytotoxic effect in ascending order was ProRoot MTA - MTA Angelus < SuperEBA < Vitrebond. Both MTA materials tested exerted mild suppression of cellular mitochondrial activity and may be characterized as biologically inert materials.

/pdf/in-vitro-evaluation-of-the-cytotoxicity-of-proroot-mta-and-3q1czuis3d.pdf

Elisabeth A. Koulaouzidou

Papers

In vitro evaluation of the cytotoxicity of calcium hydroxide-based root canal sealers

Antiproliferative effect of mineral trioxide aggregate, zinc oxide-eugenol cement, and glass-ionomer cement against three fibroblastic cell lines.

Cytotoxicity of three resin-based root canal sealers: an in vitro evaluation

In vitro evaluation of the cytotoxicity of ProRoot MTA and MTA Angelus.

Cytotoxic effects of different concentrations of neutral and alkaline EDTA solutions used as root canal irrigants.