3D printing technologies are manufacturing technologies based on computer-designed digital models that allow fabrication of layered three-dimensional objects. This review aims to present a summary of the literature published on 3D-printed polymer and composite materials in dentistry. A literature search was performed using the PubMed database to identify eligible articles. In total 508 articles were identified based on the original search query, with 362 being eliminated based on the exclusion criteria and 146 articles were screened and based on their abstracts, 68 articles were studied in detail. Subsequently, these articles were divided into three groups based on the area of application: (1) restorative dentistry, which included 3D printed crowns, bridges, and veneers; (2) regenerative dentistry and tissue engineering, such as 3D printed scaffolds; (3) fabrication of oral guides and other appliances, such as surgical guides, dental implants, and surgical splints. In this review the 3D printing technology is described, including its benefits regarding working time, accuracy and overall design and fabrication of products. The review shows that the most studied area of application of printable polymers and composites is regenerative dentistry. Even though these materials are studied for their properties and the effects on the human body as well as the environment, novel materials with specific and revolutionary characteristics that have emerged in recent years are given special attention. However, more research is needed to ensure the safety of use and confirm the characteristics of novel materials in both in vivo and in vitro conditions.