The accuracy of custom-made metal posts manufactured using selective laser sintering versus conventional casting techniques: a laboratory study

Background: The purpose of this study was to evaluate the efficacy of selective laser sintering (SLS) against the traditional casting method in fabricating customized Co-Cr dental posts, employing 3D coordinate metrology for analysis.

Methods: A 10 mm post space was prepared in a transparent acrylic block using a red ParaPost XP drill (1.25 mm diameter). An impression of this cavity was taken with a 1.143 mm diameter ParaPost impression post and auto-polymerizing acrylic resin. The resin patterns obtained were digitized with a Straumann Cares scanner, generating STL files, which were forwarded to Renishaw for the production of 10 Co-Cr posts through SLS. Simultaneously, the original resin patterns underwent investment and casting in Co-Cr alloy. The dimensional accuracy of the posts produced by both methods was evaluated using the triple scan method.

Results: The mean discrepancy was - 0.048 mm when comparing the dimensions of scanned resin posts to those of the conventionally cast posts, and - 0.067 mm between the scanned SLS-produced posts and the original resin patterns. Statistical analysis indicated no significant difference between the two sets of mean values (P = 0.107).

Conclusion: SLS technology is a viable alternative to the conventional casting technique for the manufacture of customized Co-Cr posts. Furthermore, SLS offers advantages in terms of cost and time efficiency without compromising the accuracy of the end product.