Properties and Applications of Calcium Hydroxide in Endodontics and Dental Traumatology

Department of Endodontics, Hamedan University of Medical Sciences, Hamedan, Iran.
International Endodontic Journal (Impact Factor: 2.97). 05/2011; 44(8):697-730. DOI: 10.1111/j.1365-2591.2011.01886.x
Source: PubMed


Mohammadi Z, Dummer PMH. Properties and applications of calcium hydroxide in endodontics and dental traumatology. International Endodontic Journal, 44, 697–730, 2011.
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.

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Available from: Paul M. H. Dummer, Mar 23, 2015
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    • "It is known that the pH elevation affects the integrity of the bacterial cytoplasmic membrane, leading to cellular destruction (Mohammadi & Dummer 2011). The antimicrobial action of bioactive glasses has been attributed to their ability to increase the pH in bacterial suspensions (Allan et al. 2001). "
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    ABSTRACT: Aim: To analyse the effect of commercial and experimental gutta-percha with the addition of niobium phosphate glass on biofilm formation by oral bacteria from human dental plaque. Additional pH and elemental release of the materials were analysed. Methodology: The multispecies biofilm was grown anaerobically from plaque bacteria on standardized discs of each material: hydroxyapatite (HA), gutta-percha pellets (OBT) (Obtura pellets, Shoreline, CT, USA), ProTaper gutta-percha (PTP) (ProTaper Universal Gutta-Percha Points, Dentsply Maillefer, Ballaigues, Switzerland), EndoSequence BC gutta-percha (GBC) (Brasseler USA, Savannah, GA, USA), experimental gutta-percha associated with niobium phosphate glass (GNB) and niobium phosphate glass (NPG). Specimens (n = 5 per group and per incubation period) were incubated in brain-heart infusion broth for 3, 14 and 30 days, at 37°C, and stained using Live/Dead viability assay. Images were analyzed by confocal laser scanning microscopy (CLSM) and the total biovolume (mm(3) ), viable bacteria biovolume (mm(3) ), and live percentage (%) were quantified. For pH measurement, specimens of each material (n=3) were immersed in phosphate-buffered saline at 37°C and pH was monitored in multiple intervals, up to 30 days. For elemental analysis, additional specimens (n=3) were immersed in deionized water and elemental release was analyzed by ICP-OES (Inductively Coupled Plasma - optical emission spectrometry) at time intervals of 3, 14 and 30 days. Differences between groups were evaluated by the two-way analysis of variation (ANOVA) with Tukey post hoc test (P < .05). Results: The lowest total biovolume at 30 days was found in GNB, GBC, and NPG. GNB had the lowest viable bacteria biovolume (mean value) at 30 days (p<0.05), and the lowest live percentage of bacteria at 3 and 30 days (p<0.05), while NPG had the lowest live percentage at 14 days (p<0.05). GNB had the highest pH (8.45) after 30 days (p<0.05), and the greatest Zn and Na release at all time intervals (p<0.05). Both GBC and GNB had significantly higher Ca release at 14 and 30 days. Conclusion: GNB and GBC reduced biofilm formation, GNB had the lowest amount of viable bacteria in biofilms with the highest pH, and high Zn and Na release values after 30 days. This article is protected by copyright. All rights reserved.
    International Endodontic Journal 10/2015; DOI:10.1111/iej.12558 · 2.97 Impact Factor
    • "Currently, surface disinfectants such as sodium hypochlorite (NaOCl) are used to clean and disinfect the root canal system but they often appear insufficient to eliminate microorganisms due to the complex shape of the root canal system [2]. Calcium hydroxide (Ca(OH) 2 ) is a frequently used temporary dressing with the aim to further reduce the microbial load [3]. "
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    ABSTRACT: The aim of this study is to investigate the disinfecting properties of a Modified Salt Solution (MSS) and calcium hydroxide (Ca(OH)2) in a non-direct-contact ex-vivo model. Seventy-four single-canal roots infected with Enterococcus faecalis were treated with 1% sodium hypochlorite (NaOCl) irrigation or with NaOCl irrigation with subsequent dressing with MSS or Ca(OH)2. After removal of the dressings, the roots were filled with bacterial growth medium and incubated for seven days to enable the surviving bacteria to repopulate the root canal lumen. Growth was determined by sampling the root canals with paper points before treatment (S1), after treatment (S2) and incubation after treatment (S3). The colony forming units were counted at S1 and S2. At S3, growth was determined as no/yes regrowth. The Kruskal-Wallis, McNemar and χ2 test were used for statistical analyses. At S2, in the NaOCl group, growth was found in 5 of 19 root canals. After the removal of MSS or Ca(OH)2 bacteria were retrieved from one root canal in both groups. At S3, repopulation of the root canals had occurred in 14 of 19 roots after sole NaOCl irrigation, 6 of 20 roots after MSS-dressing and in 14 of 20 roots after Ca(OH)2-dressing. MSS was more effective in preventing regrowth than Ca(OH)2 (P = 0.009). The Modified Salt Solution prevented regrowth in roots which indicates that it can eliminate persistent bacteria. Dressing the root canals with Ca(OH)2 did not provide additional disinfection after NaOCl irrigation. Copyright © 2015. Published by Elsevier Ltd.
    Journal of dentistry 07/2015; 43(10). DOI:10.1016/j.jdent.2015.07.015 · 2.75 Impact Factor
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    • "The difficulty in eliminating microorganisms that remain in the root canal system even after cleaning and shaping procedures demonstrates the need to complement chemomechanical preparation by using an intracanal medication with antimicrobial properties. Calcium hydroxide has clinical indications well-documented in the literature [1]. Its mechanism of action is directly attributed to its ability for dissociation into calcium and hydroxyl ions resulting in an increase in the local pH, which alters the biological properties of bacteria, leading to bacterial cell toxicity [2]. "
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    ABSTRACT: Objectives. To evaluate the influence of dentine on the pH of different medications in standardized simulated canals. Materials and Methods. Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medications. The simulated canals were placed in containers with 1.5 mL of deionized water and pH was monitored in multiple intervals, up to 30 days. The mean pH values were calculated and submitted to statistical analysis using paired Student's t-test and ANOVA complemented by the Tukey test (í µí± < 0.05). Results. There was no statistical difference between the groups with and without dentine powder (í µí± > 0.05). The pH values of calcium hydroxide were significantly higher than those of NPG in the first 24 hours (í µí± < 0.05). After 7 days, both behaved in a similar manner. Conclusion. The addition of dentine powder to the medications evaluated did not alter the pH of the external solution in any of the time points tested.
    The Scientific World Journal 07/2015; 2015(686259):1-5. DOI:10.1155/2015/686259 · 1.73 Impact Factor
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