Intracanal medicaments.

Intracanal medicaments in endodontics have been used for a number of reasons both in the past and currently. These include the elimination or reduction of microorganisms, rendering canal contents inert, prevention of post-treatment pain, and to enhance anesthesia. The chemical nature of medicaments employed are varied; they come from a number of different groups. Often, different chemicals or drugs are combined in a "cocktail" in an attempt to elicit a variety of effects with a single application. After reviewing in vivo and in vitro research, there is a decided lack of evidence of the clinical effectiveness of intracanal medicaments, with the exception of steroids for prevention of pain. What is clear from the research, is the toxicity and potential allergenicity of the commonly used intracanal medicaments, particularly those of the phenolic and aldehyde derivatives. Ready accessibility to periapical tissues and systemic circulation raises serious doubts as to whether their use is safe. It is also unlikely that most medicaments enhance clinical success. Considering the research, the findings of which are reinforced by clinical experience, intracanal medicaments are primarily useless. The one exception is intracanal or systemic steroids. They are effective in reducing the incidence of post-treatment pain.