Cetylpyridinium chloride: mechanism of action, antimicrobial efficacy in biofilms and potential risks of resistance.

Antimicrobial resistance is a serious issue for public healthcare all over the world. While resistances toward antibiotics have attracted strong interest among researchers and the general public over the last two decades, the directly related problem of resistance toward antiseptics and biocides has been somewhat left untended. In the field of dentistry, antiseptics are routinely used in professional care, but they are also included in lots of oral care products such as mouthwashes or dentifrices, which are easily available for consumers over-the-counter. Despite this fact, there is little awareness among the dental community about potential risks of the widespread, unreflected and potentially even needless use of antiseptics in oral care. Among others, cetylpyridinium chloride (CPC), a quaternary ammonium compound, which was firstly described in 1939, is one of the most commonly used antiseptics in oral care products and included in a wide range of over-the-counter products such as mouthwashes and dentifrices. The aim of the present review is to summarize the current literature on CPC, particularly focusing on its mechanism of action, its antimicrobial efficacy toward biofilms, and on potential risks of resistances toward this antiseptic as well as underlying mechanisms. Furthermore, this work aims to raise awareness among the dental community about the risk of resistance toward antiseptics in general.