Are 3D printed resin surgical splints safe to use in the mouth? A comparative in vitro study

Introduction

In orthognathic surgery, surgical splints made of polymethymethacrylate or its variants are used to position the jaws before osteofixation, and occasionally left in-situ for a short duration to guide the occlusion postoperatively. However, allergic reactions can be caused by unreacted dental resin (monomers). Computer aided design/Computer Aided Manufacturing (CADCAM) surgical splints are now more commonly used than the conventionally “handmade” splints. It is unclear if these splints contain uncured residual monomers in any detectable quantity.

Materials and methods

CADCAM surgical splints were made from 2 commonly used resins and compared with splints made manually with autopolymerising resin. The splints were immersed in saline at 37°C for 2 weeks to simulate use in the mouth, and the contents were analysed for uncured resin leaching with High Power Liquid Chromatography (HPLC) at different time intervals.

Results

Uncured resin content was higher in the conventionally made splint (15,246µg/L on Day 1, 13,539 µg/L on Day 7, and 6,203µg/L on Day 14). One of the CADCAM resins had undetectable monomer quantities, while the other CADCAM resin demonstrated significantly less free monomer compared to the autopolymerising resin (382 µg/L on Day 1, 179 µg/L on Day 7 and 65.2 µg/L on Day 14).

Conclusion

CADCAM surgical splints have much lower free monomer content compared to the conventionally made splint, and are safe for clinical use.