A dental post is a permanent restoration fixed permanently in the patient’s tooth. The post consists of radicular and coronal parts. The former is responsible for the retention of the entire restoration, while the latter one restores lost tissues of the tooth crown. Many types of dental posts are used. However, the individual ones offer the most conservative preparation of a tooth canal, subsequently preserving the remaining tooth tissues. This directly increases the strength of the future restoration. Correct preparation of the individual post depends on the accuracy of the canal reproduction and the quality of the impression. The purpose of this study was to determine the best method of taking dental impressions for the most precise post preparation. A total of 162 impressions obtained by means of three methods were taken (54 teeth each): the PISTOL method, where the impression materialwas injected into the root canal using a standard impression pistol, the LENTULO method, where the material was injected into the root canal using a standard impression pistol and was subsequently condensed with a Lentulo needle, the NEEDLE method, where an injection needle was inserted into the canal, followed by an injection of the impression material with a standard impression pistol. After setting, the impressions were analysed clinically, independently by two dentists, followed by an independent, digital analysis. The results showed that the best method to obtain the precise root canal impression in both single- and multi-canal teeth is the LENTULO method, while the worst is the PISTOL method.