## 4 Discussion
VR allows the clinician to demonstrate to patients the expected clinical outcome via a total virtual simulation. However, AR may allow for an immediate interaction between the dentist and patient. An AR device can create a 3D model that can be placed directly in the patient's mouth, therefore providing 3D visualization for aesthetic planning [85]. An AR system can share the operator's reality with the dental technician or another specialist when formulating a treatment plan. AI and Robotics represent the new frontiers of digital dentistry. The artificial nature of AI allows for the elimination of potential human error, bias and feelings such as fatigue, tiredness, and boredom, which can manifest after repetitive work [86]. Human intelligence is denoted by perception and interpretation. AI cannot replace human intelligence but can instead support human interpretation and action. AI machines develop problem-solving abilities through independent learning and by utilizing human senses and mechanisms of the human mind [61]. The realization of machines learning through a bio-inspired artificial neural network is a widely used method in AI [87]. These innovative features of AI can be applied to medical decision making, offering the possibility of helping clinicians obtain expert-level information [88]. As the use of AI increases in the medical field, the role of AI in dentistry may also expand and become a reliable and friendly tool used in daily practice. While AI helps in developing diagnosis and prognosis, robotics can assist clinicians through computer-assisted interventions. Robot dental assistants and other applications are promising; however, critical challenges limit progress, such as high costs and complex operability of the systems. Further research is needed, as the latest changes in modern robot technology have not yet been fully introduced to dental research nor have they reached technological readiness and cost efficiency to enter the dental market [58]. Data provided by multiple digital technologies, such as photographs or 3D-tracking devices, radiographic information, or intraoral images, can be integrated using these novel technologies. This integrated digital information allows for the creation of a digital patient (\"virtual patient\"). A clinician can then use the \"virtual patient\" to directly develop a digital treatment plan on screen. Possible uses include the simulation of the procedures such as surgical navigation for implant placement, design of restorations, or navigated endodontics. Moreover, using different virtual patients can allow for a patient-centred approach driven by patient-centred outcomes. Although this work made an overview of the potential use of VR, AR, MR, AI and Robotics in dentistry, information about their precise application in the different disciplines is still lacking. Moreover, limited data are available regarding the effect of such devices on the cognitive load of the users. While a recent systematic review reported a lower or equal cognitive load of these new devices with higher performance, when compared to more traditional conditions such as display- or paper-based instructions [89], data regarding the cognitive load during their clinical or educational applications are still missing. Ethical aspects, learning theories and cognitive load should be further investigated to better exploit their potential.