Properties and applications of calcium hydroxide in endodontics and dental traumatology

Abstract

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 Ca(2+) 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.

Antimicrobial Activity and Biocompatibility of the Psidium cattleianum Extracts for Endodontic Purposes

“…The persistence of some microorganisms, like Enterococcus faecalis and Candida albicans in cases of endodontic treatment failures and Actinomyces israelii and Pseudomonas aeruginosa in refractory periapical lesions, associated with the complex anatomy of the root canal system require irrigants and dressings with a large spectrum of antimicrobial action for better disinfection (1)(2)(3). The most commonly used antimicrobial agents in endodontics are calcium hydroxide (CH) and chlorhexidine (CHX) (4,5). Although most endodontic pathogens are effectively eliminated by CH, E. faecalis and C. albicans can be resistant, depending on the CH vehicles (6).…”

Efeitos da dentina sobre o pH e atividade antimicrobiana de diversas formulações com hidróxido de cálcio

“…Apesar de apresentar satisfatória atividade antimicrobiana e neutralizante de subprodutos da microbiota presente na infecção endodôntica primária, tais como a endotoxina, sua ação sobre o Enterococcus faecalis é restrita [2][3][4][5] .…”

“…O digluconato de clorexidina a 2% possui boa atividade antimicrobiana sobre o Enterococcus faecalis 1 , porém é questionável sua efetividade sobre a microbiota anaeróbia estrita 3 . Assim, é recomendável a associação com o hidróxido de cálcio, a fim de também proporcionar sinergismo de ação para ambas as substâncias 3,6,7 .…”

“…Assim, é recomendável a associação com o hidróxido de cálcio, a fim de também proporcionar sinergismo de ação para ambas as substâncias 3,6,7 . Entretanto, devido à restrita miscibilidade entre essas substâncias, a medicação resultante é de difícil manuseio e restrita aplicabilidade clínica, além de apresentar baixa tolerabilidade tecidual 8,9 .…”

Antibacterial activity of intracanal medications based on calcium hydroxide and zinc oxide micro- or nanoparticles: an ex vivo study

“…Calcium hydroxide is used as medication in teeth with pulp necrosis, promoting microorganism reduction in the RCS, favoring the endodontic treatment success 2 . Calcium hydroxide (CH) has antimicrobial effect, due to its dissociation into Ca + and OH -ions, promoting an alkaline pH 1,3 and interaction with the microorganism cell wall, and inactivating bacterial byproducts such as endotoxin [4][5][6] .…”