3D-Printed Composite Performance Compared to Cartridge and Milled PMMA Temporary-Materials

Objectives: The aim of this study was to compare high-strength 3D-printed material (3DP-M) with three materials traditionally used for temporary to long-term-temporary restauration, by investigating in-vitro performance and fracture force of fully-anatomical anterior implant-supported temporary-partial-dentures (TPD, tooth situation (11-13)), 3-point-bending strength (3PBS) and modulus (3PBM), water sorption (WS), Martens hardness (HM) and pin-on-block wear (PW).
Methods: Identical TPDs (n=8 per series) were 3D-printed of methacrylate-based composite resin (PRO-Resins-Crown-X), milled of PMMA-based discs (polycon®-ae,REF1) and acrylate/microfiller composite discs (VITA®-CAD-Temp®,REF2) and fabricated of cartridge PMMA material (3M™-Protemp™-4,REF3). After polishing and adhesive fixation, combined thermal cycling and mechanical loading (TCML) was performed on all TPDs to mimic 5-year clinical application. Behavior during TCML and fracture force were determined and failures were analyzed. HM according ISO14577-1 and mean and maximum wear after PW were measured (n=8 per series). Data was statistically investigated (ANOVA; post-hoc-Bonferroni, α=0.05).
3PBS and 3PBM (n=12 to 15 per series) and WS (n=5 per series) were measured according ISO10477 for REF1, REF2 and 3DP-M.
Results: All TPDs except one reference specimen survived TCML without failures. Mean fracture values of the surviving specimens varied between 716±156N and 941±88N without significant individual differences between 3DP-M and references. Failures were characterized by fracture of the connector (n=20) followed by fractures at the abutment (n=18). HM of 3DP-M (292.4±8.7) was significantly (p<0.001) higher as compared to all individual references (165.6±13.0 to 209.3±10.4). PW varied between -136.4µm (3DP-M) and -473.7µm (REF1) with individually significant (P<0.05) difference between 3DP-M and REF1. 3PBS, 3PBM and WS varied between 76.17±4.75MPa (REF2) and 127.36±11.10MPa (3DP-M), 3114.64±37.40MPa (REF1) and 5596.36±408.92MPa (3DP-M) and 15.01±0.35µg/mm3 (3DP-M) and 26.11±0.31µg/mm3 (REF1).
Conclusions: 3D-printed material showed comparable to better in-vitro performance than standard cartridge and milling material, and therefore may be sufficient for long-term temporary restauration.