State of the art of dental impressions: digital techniques

Trabalho final do 5º ano com vista à atribuição do grau de mestre no âmbito do ciclo de estudos de Mestrado Integrado em Medicina Dentária apresentado à Faculdade de Medicina da Universidade de Coimbra.Introduction: Among keystones for the prognosis of fixed prosthesis rehabilitations are the impression quality and the respective work model. During conventional impressions, some errors induced by issues related to materials, techniques or human errors could occur and lead to information loss. 3D dental scanners have been in development since the 80’s and they are a link to present and future of dental impressions and dental restorations. Objective: The main objective of this pilot study is to evaluate the trueness of the iTero® CDIS by comparing the dimensions of a virtual model obtained by digital impression, the original model and the correspondent plaster model obtained by a traditional impression. Materials and Methods: The pilot study was divided in two parts, both using the iTero®, and five Frasaco AG-3 acrylic teeth FDI 46, which were then impressed by a conventional technique and poured with type IV dental plaster. The first part consisted of the comparison of the measurements of the scanned acrylic teeth with the acrylic teeth and the dental plaster teeth, measured with a digital caliper. The second part compared the acrylic and dental plaster teeth while scanned by the iTero® and measured by it. Results: On the first part of the pilot study, a pairwise comparison test showed a statistical match (P>0.05) between the acrylic teeth and the iTero®, and the dental plaster teeth and the iTero®. On the second part, iTero® readings comparison of both acrylic and dental plaster models showed no statistical differences. Conclusion: Digital impressions seem a promising tool to be explored in the near future, even though more tests are required to evaluate its in-vivo performance. The iTero® dental scanner according to our pilot study, and considering its limitations, reflects trueness on the measurements performed