Which 3D printing parameters impact the mechanical and structural properties of occlusal devices? A systematic review of methods.

STATEMENT OF PROBLEM: Variations in 3-dimensional (3D) printing parameters generate uncertainties regarding the mechanical properties and durability of occlusal devices.

PURPOSE: This methodological review aimed to identify and analyze the available scientific evidence regarding the influence of printing parameters on the mechanical properties of occlusal devices manufactured using 3D printing.

MATERIAL AND

METHODS

Searches were conducted in the PubMed, Embase, Scopus, Web of Science, and LILACS databases, as well as in nonpeer-reviewed literature through a Google Scholar search, by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist. In vitro studies that evaluated the mechanical and structural properties of 3D printed occlusal devices, considering printing variables such as material composition, printer type, layer thickness and orientation, washing and postpolymerization protocols, and influencing variables such as storage and aging conditions were included.

RESULTS

The included studies consistently demonstrated that printing parameters influenced the mechanical and structural properties. Most studies indicated that thinner layers (25 to 50 μm) and printing angles of 45-degree orientation result in better mechanical properties and greater dimensional accuracy. Water immersion and thermocycling negatively influenced the mechanical properties. Light-polymerized resins showed significant mechanical improvements when associated with adequate postpolymerization treatment.

CONCLUSIONS

The mechanical performance of 3D printed occlusal devices is influenced by printing parameters, postpolymerization, and aging conditions.