Clinical Investigation of the Effectiveness of Glycyrrhizin as Intracanal Medication in Root Canal Disinfection and Inflammatory Cytokines

Periodontitis is a dynamic inflammatory process located at the periapical region, the type of immune-inflammatory response to periapical periodontitis is determined by a network of chemical mediators produced by immune cells in response to the stimulus caused by the action of microorganisms and/or virulence factors. This may result in damage to the tissues and in the development of endodontic signs and symptoms (1-3).

In infected root canals, the destruction of periapical tissues is mediated by tumor necrotizing factor (TNF-α) and interleukin-1β (IL-1β) that appears to be directly related to high levels of infectious content present in the root canal (4). Arachidonic acid metabolism plays a key role in many inflammatory diseases, one of its products is the prostaglandin E2 (PGE2) which has been also shown to potentially stimulate bone resorption and to inhibit reparative bone formation in vitro and in vivo (5). Particularly, IL-1β, TNF-α, and PGE2 have been detected in periapical tissues (6-9), being considered as an important inflammatory biomarker in the periapical disease (1, 2, 5, 7, 10).

To identify a specific inflammatory mediator as a diagnostic marker of disease status, the mediator should not only be present or elevated in disease and absent or low in health, but it should also longitudinally increase during active disease progression and subside following therapy (5).

Although instrumentation may be assumed to be of greater importance in the clinical practice, the use of intracanal medication has been proven to optimize the root canal disinfection (11-14). As root canal medicaments can come in direct contact with periapical tissues, in addition to having good antibacterial ability and being biocompatible, so a wide variety of intracanal medications have been proposed. In selecting root canal medicaments, it is necessary to consider their therapeutic benefits against their potential cytotoxic effects. Ideal root canal medicaments should have strong antibacterial properties and minimal cytotoxic effect on the host tissues (11-16).

Calcium hydroxide (Ca(OH)2) has been used extensively in dentistry since the 1920s (17). Today, it is still the most commonly used endodontic medicament throughout the world(18).Ca(OH)2 also inactivates lipopolysaccharide so it can assist in periapical tissue repair (19).