IADR Abstract Archives
UV-VIS Spectral Profiles of Probable Photoinitiators in 3D Dental Resins
Objectives: Dental 3D printing resins utilize a different range of wavelengths for photo-activation than those commonly found in visible light-cured, direct dental restorative materials, and thus contain different photoinitiators (PIs). This project sought to provide preliminary identification of PIs present in a wide variety of commercial, 3D photo-printing dental resins.
Methods: Eleven 3D dental, photo-printing resins were obtained among 5 commercial manufacturers/suppliers: NextDent (Base Resin, Ortho IBT, Ortho Model), Asiga (Dentamodel), Dreve (Fotodent Guide, Fotodent Model, Fotodent Cast), Octave Light (White Model Resin), SprintRay (Splint Resin, Surgical Guide Resin, Dental Model). Samples of a variety of known commercial photoinitiators used in UV-printing were obtained: Lucirin-TPO, TPO-L, and many from the Omnirad (previously Irgacure) product line: 2100, 819, 184D, 1173, and 369. Commercial PIs were dissolved in ethanol, and UV/VIS absorption spectra were obtained: broad-banded light source/quartz cuvette holder (ISS-UV/VIS, Ocean Optics (OO)), mini-spectrometer (USB 2000+, OO), software (SpectraSuite, OO). Similar absorption spectra were obtained for the 3D dental resins. Known PI spectra between 350 and 450 nm were overlaid, along with the spectrum of a single dental 3D print product. Preliminary identification of the PI in each dental 3D resins was attempted, using qualitative comparison between spectral absorption profiles of that resin compared to the library of profiles collected for the known commercial PIs.
Results: PI identification was strongly supported in 8/11 of the 3D dental products: Lucirin TPO in 3, and OMNIRAD 819 in 5. For three of the 3D print resins, the spectral profiles of probable initiators within this spectral region could not be correlated with any of the PIs within the library tested.
Conclusions: The majority of 3D dental printing resins demonstrated the probable use of OMNIRAD 819 (a very efficient, but expensive PI), with fewer resins suggesting use of the less efficient, less expensive PI (Lucirin-TPO).
Methods: Eleven 3D dental, photo-printing resins were obtained among 5 commercial manufacturers/suppliers: NextDent (Base Resin, Ortho IBT, Ortho Model), Asiga (Dentamodel), Dreve (Fotodent Guide, Fotodent Model, Fotodent Cast), Octave Light (White Model Resin), SprintRay (Splint Resin, Surgical Guide Resin, Dental Model). Samples of a variety of known commercial photoinitiators used in UV-printing were obtained: Lucirin-TPO, TPO-L, and many from the Omnirad (previously Irgacure) product line: 2100, 819, 184D, 1173, and 369. Commercial PIs were dissolved in ethanol, and UV/VIS absorption spectra were obtained: broad-banded light source/quartz cuvette holder (ISS-UV/VIS, Ocean Optics (OO)), mini-spectrometer (USB 2000+, OO), software (SpectraSuite, OO). Similar absorption spectra were obtained for the 3D dental resins. Known PI spectra between 350 and 450 nm were overlaid, along with the spectrum of a single dental 3D print product. Preliminary identification of the PI in each dental 3D resins was attempted, using qualitative comparison between spectral absorption profiles of that resin compared to the library of profiles collected for the known commercial PIs.
Results: PI identification was strongly supported in 8/11 of the 3D dental products: Lucirin TPO in 3, and OMNIRAD 819 in 5. For three of the 3D print resins, the spectral profiles of probable initiators within this spectral region could not be correlated with any of the PIs within the library tested.
Conclusions: The majority of 3D dental printing resins demonstrated the probable use of OMNIRAD 819 (a very efficient, but expensive PI), with fewer resins suggesting use of the less efficient, less expensive PI (Lucirin-TPO).
