3D-Printed Teeth in Endodontics: Why, How, Problems and Future—A Narrative Review

Abstract

Three-dimensional printing offers possibilities for the development of new models in endodontics. Numerous studies have used 3D-printed teeth; however, protocols for the standardization of studies still need to be developed. Another problem with 3D-printed teeth is the different areas of literature requested to understand the processes. This review aims to gather evidence about 3D-printed teeth on the following aspects: (1) why they are advantageous; (2) how they are manufactured; (3) problems they present; and (4) future research topics. Natural teeth are still the standard practice in ex vivo studies and pre-clinical courses, but they have several drawbacks. Printed teeth may overcome all limitations of natural teeth. Printing technology relies on 3D data and post-processing tools to form a 3D model, ultimately generating a prototype using 3D printers. The major concerns with 3D-printed teeth are the resin hardness and printing accuracy of the canal anatomy. Guidance is presented for future studies to solve the problems of 3D-printed teeth and develop well-established protocols, for the standardization of methods to be achieved. In the future, 3D-printed teeth have the possibility to become the gold standard in ex vivo studies and endodontic training.

Shaping ability of novel nickel‐titanium systems in printed primary molars

“…Laboratorial endodontic studies in primary teeth are challenging to establish an adequate and standard sample group since most of the primary teeth with an indication for extraction have physiological or pathological root resorption 15 . With the development of 3D printing technology, 3D‐printed resin replicas of primary teeth may be an alternative to overcome some problems with extracted teeth: standardization, difficulty getting enough numbers, and potential cross‐infection risks 16 . Using CBCT data from an extracted tooth associated with 3D printing technology, it is possible to obtain a model of a natural tooth with the same external and internal morphology 17,18 .…”

“…15 With the development of 3D printing technology, 3D-printed resin replicas of primary teeth may be an alternative to overcome some problems with extracted teeth: standardization, difficulty getting enough numbers, and potential cross-infection risks. 16 Using CBCT data from an extracted tooth associated with 3D printing technology, it is possible to obtain a model of a natural tooth with the same external and internal morphology. 17,18 Thus, 3D printing technology allows one to compare endodontic instruments' shaping abilities in standardized primary teeth samples.…”

Modular training model for education of students in restorative and prosthodontic dentistry

“…To achieve a significant result and a power of π = 0.80 an unrealistic number of 732 students would be needed. In comparison to most other studies, the number of participants was two to three times higher in the present study 1–21 . The printed teeth and new model were assessed with a questionnaire.…”

“…As an example, for one-layer printed teeth in different studies, [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] a one-layer tooth was printed and called type I (Figure 3). The total evaluation of this type was significant worse (Ø 3.6 ± 1.1) than the other tooth types (type II Ø 2.5 ± 1.0, type III Ø 2.4 ± 1.0 and typodont tooth Ø 2.7 ± 1.1).…”

“…The different printed tooth types were compared to a standard typodont tooth (KaVo) and real teeth. As an example, for one‐layer printed teeth in different studies, 7–23 a one‐layer tooth was printed and called type I (Figure 3). The total evaluation of this type was significant worse (Ø 3.6 ± 1.1) than the other tooth types (type II Ø 2.5 ± 1.0, type III Ø 2.4 ± 1.0 and typodont tooth Ø 2.7 ± 1.1).…”