## 3 Results
### Applications in Pre-Clinical Education  
A significant proportion of dental education is dedicated to teaching clinical psychomotor skills, and often, the dentist trains directly on the patient [17]. Currently, dental schools use realistic patient simulators with dental models incorporated to simulate a dental treatment [18]. These simulators allow the instructors to demonstrate techniques aimed at improving the hand-eye coordination and manual dexterity of students. Moreover, during the activities on the simulators, dental students require constant tutor feedback on their work for understanding better the procedures before moving on to the subsequent procedures.  
During the COVID-19 pandemic, limitations in pre-clinical education have been highlighted, as many dental students could not be trained at their university and lacked the direct support of the tutor. In this COVID-19 era, the most important issue for pre-clinical and clinical education is achieving the balance between the training of dental students and limiting the spread of infected cases [19; 20]. It is for this reason, because of the development  
\begin{table}
\begin{tabular}{l|c} \hline \hline
**Inclusion Criteria** & **Exclusion Criteria** \\ \hline Original articles describing the application of & Opinion or narrative discussions that did not \\ virtual, augmented and mixed reality, artificial intelligence, and robotics in dentistry (at least & report on the use of virtual and or augmented \\ one of them) & reality, artificial intelligence, and robotics in \\ Available in the English language & Detailed programming for virtual reality, \\ Published in peer-reviewed academic or & abstracts, conference proceedings, letters to the \\ professional journals & editor and, case reports were excluded. \\ \hline \hline \end{tabular}
\end{table}
Table 1: List of inclusion and exclusion criteria.  
of innovative instruments to train and teach the basic clinical procedures to the dental students, that replicating dental reality as much as possible became of paramount importance.  
Considering these aspects, AR, VR and MR represent innovative educational tools which allow self-education of the student. While the description of the tactile sensation of clinical procedures by the tutor may be difficult to explain using the traditional simulator, the presence of direct feedback and pressure sensors may be useful to overcome this problem by using VR or MR [21]. In a previous study by [PERSON] et al., the performance on a simulated caries removal of undergraduate dental students was compared to prosthodonics residents using a novel haptic VR simulator [22]. Their results showed that efficiency, defined as percentage of carious lesion removed over drilling time, improved significantly over the experiment for both novice and experienced operators [22]. In addition, [PERSON] et al. examined the use of VR in dental education and highlighted a significant positive effect on the student performance and the appreciation of the 3D environment compared to 2D [23].  
Similar to traditional simulators, VR or MR simulators provide digital teeth models, digital handpieces equipped with an air and water in-and-out system and different types of digital burs. In addition, these simulators may provide instant feedback for the students making full use of the lab training time and improving students' manual dexterity skills before confidently moving onto clinical setting with patients. Table 2 summarizes and compares different dental simulators currently used [21].