Dentists’ Knowledge of Radiation Protection, Justification, and Optimization Practices: A Systematic Review

Background/Objectives: Radiation protection in dental medicine is based on the principles of justification and optimization, yet available evidence indicates inconsistent application of these principles in everyday practice. The aim of this systematic review was to assess dentists’ understanding of radiation protection and their adherence to guidelines for justification and optimization of dental X-ray procedures. Methods: A systematic search of the PubMed and Scopus databases was conducted from January 2010 to April 2026, following PRISMA guidelines. The systematic review included surveys and cross-sectional studies that examined dentists’ knowledge of radiation protection, as well as justification and optimization practices. The quality of the included studies was assessed using the Newcastle–Ottawa scale adapted for cross-sectional studies. Results: The systematic review included 22 original scientific articles that assessed knowledge of radiation protection, justification, and optimization practices among 5277 dentists from 12 countries. The findings indicate a high theoretical understanding of the basic rules of radiation protection, but a lower level of understanding of the technical and optimization factors of dental X-ray devices. A relevant inconsistency was observed in the justification process, with frequent referral for X-ray imaging without clinical indication and inconsistent adherence to guidelines. The optimization of X-ray imaging varied, especially in failing to adjust exposure parameters and in the restricted use of rectangular collimators. Inadequate quality control of X-ray devices and insufficient continuous professional training in radiation protection and imaging optimization are examples of organizational and infrastructural factors that lead to higher radiation exposure. Conclusions: Although many guidelines exist, there remains a noteworthy disparity between theoretical understanding and clinical practice in dental radiation protection. To reduce patients’ and dentists’ exposure to ionizing radiation, it is important to include radiation protection education in the basic dental curriculum, establish and improve continuous training, standardize clinical procedures, and enable broader application of systems for optimization and quality control.