Using Reverse Engineering to Assess Precision of Digital Replicas of Dental Arches in Occlusion

As in many other fields, digital technologies are playing an important role in transforming the practice of dentistry. Many processes can now be carried out with CAD/CAM tools and among them is the intraoral scanner. The intraoral scanner is an optical scanner designed to replicate the dental arches virtually and reproduce the position between them. Traditionally, this positioning has been done using wax registers, but thanks to intraoral scanners and the software associated to them, it is possible to relate and position them digitally. However, these digital processes have not yet prevailed over conventional methods, and one of the reasons for this may be doubts about the accuracy of these processes. This study measures the precision of the upper and lower arch alignment processes. The study consisted of performing digital arch alignments, taking as reference the occlusal records obtained also with an intraoral scanner. These occlusal records were obtained following two different methods: the one proposed by the manufacturers of the intraoral scanners and a new method that makes it possible to obtain these records in patients with overbite. The results show that the precision of arch alignments is higher following the protocols proposed by the manufacturers. However, these protocols are no longer valid for patients with overbite and the proposed method, despite giving worse precision values, enables the alignment of the arches.