DOI: 10.14457/tu.the.2018.1694
title: Development and effectiveness of the multilayered caries model and visuotactile virtual reality simulator for minimally invasive caries removal

description: Backgroud: While operative skills laboratory training is one of the significant substances in dental education, there are some limits in simulation models that resemble the actual situation. The setting presented multiple disorientation, confronts when the students move in real clinical setting of treating patients. Virtual reality (VR) training is one of the effective methods providing the dental students meet thereal clinical complexities. A multilayer model which imitating carious tooth structures that has dissimilar hardness was required for caries removal procedure simulation. In Minimal Invasive dentisty concept, elimination of the heavily infected dentin and preservation of the residual affected dentin were thus defined as prerequisites for effectively obstructing the caries process without harming the longterm survival of the pulp and the restoration. The bond strength of adhesives restorative material to carious dentin has been reported to be inversely comparative to the degree of caries development, with caries-infected dentin showed the lowest bond strength.Materials and Methods: This work presents the development of multilayered caries model with a visuo-tactile virtual reality simulator and a randomized controlled trial protocol to determine the effectiveness of the simulator in training for minimally invasive caries removal. A three-dimensional, multilayered caries model wasreconstructed from 10 micro-computed tomography (CT) images of deeply carious extracted human teeth before and after caries removal. The full grey scale 0-255 yielded a median grey scale value of 0-9, 10-18, 19-25, 26-52, and 53-80 regarding dental pulp, infected carious dentin, affected carious dentin, normal dentin, and normal enamel, respectively. The simulator was connected to two haptic devices for ahandpiece and mouth mirror. The visuo-tactile feedback during the operation varied depending on the grey scale. Sixth-year dental students underwent a pretraining assessment of caries removal on extracted. Results: The validity demonstrated good to excellent face validity for the minimally invasive caries removal simulator with high consistency between participants with a Cronbach alpha of 0.726. Favourable responses predominated for all questions, where the average response was neutral. The students were then randomly assigned to train on either the simulator (n=16) or conventional extracted teeth (n=16) for 3 days, after which the assessment was repeated. The posttraining performance of caries removal improved compared with pretraining in both groups (Wilcoxon, p&lt;0.05). Theequivalence test for proportional differences (two 1-sided t-tests) with a 0.2 margin confirmed that the participants in both groups had identical posttraining performance scores (95% CI=0.92, 1; p=0.00).Conclusion: training on the micro-CT multilayered caries model with the visuotactile virtual reality simulator and conventional extracted tooth had equivalent effects on improving performance of minimally invasive caries removal.