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The biomechanics of transplanted teeth remain poorly understood due to a lack of models. In this context, finite element (FE) analysis has been used to evaluate the influence of occlusal morphology and root form on the biomechanical behavior of the transplanted tooth, but the construction of a FE model is extremely time-consuming. Model order reduction (MOR) techniques have been used in the medical field to reduce computing time, and the present study aimed to develop a reduced model of a transplanted tooth using the higher-order proper generalized decomposition method. The FE model of a previous study was used to learn von Mises root stress, and axial and lateral forces were used to simulate different occlusions between 75 and 175N. The error of the reduced model varied between 0.1% and 5.9% according to the subdomain, and was the highest for the highest lateral forces. The time for the FE simulation varied between 2.3 and 7.2 h. In comparison, the reduced model was built in 17s and interpolation of new results took approximately 2.10−2s. The use of MOR reduced the time for delivering the root stresses by a mean 5.9 h. The biomechanical behavior of a transplanted tooth simulated by FE models was accurately captured with a significant decrease of computing time. Future studies could include using jaw tracking devices for clinical use and the development of more realistic real-time simulations of tooth autotransplantation surgery.

Abstract Objectives An innovative calibrated bur, aiming to improve precision during reduction of the incisal edge, was recently proposed to guide practitioners during tooth preparation. However, limited information is available concerning its usefulness in dental preclinical education. The aim of this study was to evaluate whether using this innovative guided bur improves learning experience quality and the performance of students during tooth preparation. Material and methods After having provided written consent, 60 second‐year students were divided into two groups. One group used a 1‐mm rounded bur to perform depth grooves, whereas the second group used the innovative guided bur, consisting in a 2‐mm‐depth marker with a stopping surface. Once the grooves were obtained, they were then connected using the same wheel bur in both groups. The aim was to obtain a final 2‐mm reduction of the incisal edge. Quality of the learning experience (stress level, motivation to restart, self‐evaluation of the preparation, and difficulty) was quantified using a visual analog scale. Duration of the procedure was also measured in both groups. 3D measurements for each tooth were performed using an STL comparison software. Results There were no significant differences between groups in terms of stress and self‐evaluation of the preparation. Students in the guided bur group reported significantly lower perception of exercise difficulty (p

Abstract Background Incisor loss constitutes a strong aesthetic and psychologic traumatism for the patient and it remains a challenging situation for the dental practitioner because of the necessity to rapidly replace the lacking tooth. Various therapeutic procedures have been proposed to replace the incisor concerned, for example by using a removable partial denture. However, the manufacturing of such a denture with classical procedures is often subject to processing errors and inaccuracies. The computer-aided design and computer-aided manufacturing (CAD-CAM) technology could represent a good alternative, but it is currently difficult because of the lack of dental softwares able to design easily immediate removable partial dentures. Case presentation A 30-year- patient complained about pain caused by a horizontally and vertically mobile maxillary right central incisor. After all options were presented, extraction of the traumatized incisor was decided due to its very poor prognosis, and the patient selected the realization of a removable denture for economic reasons. The present paper proposes an innovative procedure for immediate removable denture, based on the use of an intraoral scanner, CAD with two different softwares used sequentially, and CAM with a 5-axis machine. Conclusions We show in this report that associating an intraoral scanner and CAD-CAM technology can be extended to immediate dentures manufacturing, which could be a valuable procedure for dental practitioners and laboratories, and also for patients.

The instrumental fracture is a common endodontic complication that is treated by surgical or non-surgical removal approaches. However, no tool exists to help the clinician to choose between available strategies, and decision-making is mostly based on clinical judgment. Digital solutions, such as Finite Element Analysis (FEA) and Virtual Treatment Planning (VTP), were recently proposed in maxillofacial surgery. The aim of the current study is to present a digital tool to help decide between non-surgical and surgical strategies in a clinical situation of a fractured instrument. Five models have been created: the initial state of the patient, two non-surgical removal strategies using a low or high root canal enlargement, and two surgical removal strategies using a 3- or 6-mm apicoectomy. Results of the VTP found a risk of perforation for the non-surgical strategies and sinus proximity for surgical ones. FEA showed the lowest mechanical risk for the apicoectomy strategy. A 3-mm apicoectomy approach was finally chosen and performed. In conclusion, this digital approach could offer a promising decision support for instrument removal by planning the treatment and predicting the mechanical impact of each strategy, but further investigations are required to confirm its relevance in endodontic practice.