Comparison of Selective Laser Melting and Stereolithography Etching Templates for Guided Endodontics

Abstract

Objectives: To compare the accuracy and reliability of selective laser melting (SLM) and stereolithography etching (SLA) guided endodontics templates on posterior teeth. 

Methods: The teeth were randomly assigned to either SLM or SLA group. Preoperative cone-beam computed tomography (CBCT) and a three-dimensional (3D) scanner were used to establish the 3D root canal system and the precise tooth occlusal surface model. The virtual access to the canal access was designed using Mimics 19.0 and 3-Matic 11.0, according to root canal access. The endodontic access was performed based on either SLM or SLA templates. The accuracy of endodontic preparation was measured in 3 dimensions by calculating deviations from planned accesses. The template height and tooth substance loss rates in each group were measured. 

Results: SLM resulted in lower mean deviation at the entry point and apical portion of the bur in both the total and molars (P < 0.05). Moreover, there was a significant difference in angular deviations and height of template in both the total teeth and molars (P < 0.05). The mean substance loss rate of the SLA group was slightly greater than that of the SLM group, but the difference was not statistically (P > 0.05). 

Conclusion: SLM-guided endodontics provides a more predictable and precise location of root canal orifice for the treatment of posterior teeth.

Clinical significance: Comparing with stereolithography etching guided endodontics, selective laser melting had greater performance on the minimally invasive endodontic treatment of posterior teeth.

Keywords: Guided endodontics, accuracy, root canal treatment, pulp canal obliteration.