A dental post includes a composite material such as long fibers embedded in a resin matrix, and is able to transmit visible radiation when it is lit by a dental lamp to ensure polymerization of a product for setting in a tooth's root canal. The post, which has a specific color determined at ambient temperature before insertion into said canal, and which contains at least one thermochromic substance able to provide said specific color, loses its color when in place in the canal. A method for forming the dental post and a kit including a plurality of dental posts and drills are also disclosed.