A pilot study on three-dimensional printing of stainless steel arch bars for orthognathic segmental jaw surgeries

Abstract

Introduction

The fabrication process of an arch bar used during a corrective jaw surgery is traditionally labour intensive and time consuming when done manually by a dental technician. The objectives of this study are therefore to test the feasibility of using selective laser melting (SLM) to directly print patient-specific stainless steel (SS316L) arch bars from computer-aided-design (CAD) files and investigate the most optimal printing parameters to achieve that.

Material and methods

An initial print-out of 72 SS316L test coupons was done to determine the most optimal print orientation and print bed location based on chemical composition and mechanical test results from 4 different printer settings:

Parameter 1: 200 W, 50 µm

Parameter 2: 150 W, 50 µm

Parameter 3: 200 W, 30 µm

Parameter 4: 150 W, 30 µm

Ten archived digital lower dentition scans were then used to produce 10 CAD files for 3D printing of 280 dental arch bars using the aforementioned parameters. All 3D printed arch bars were then assessed for fit and subjected to physical testing.

Results

Test coupons printed using parameter 4 in the horizontal print bed (0°) location had the best mechanical properties. Similarly, for 3D printed arch bars, those printed using parameter 4 had the highest proportion of arch bars with satisfactory fit. The most common area of distortion is the posterior molar region.

Conclusion

3D printing of SS316L dental arch bars is feasible via a digital workflow using low laser power (150 W) and low layer thickness (30 µm) in a Renishaw AM 400 printer (from Renishaw plc, Gloucestershire).