<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec>
<h3>Objective</h3>
<p>Three-dimensional (3D) printing technology represents a novel method for manufacturing aligners. The aim of the present study was to assess the in-vitro cytotoxicity of 3D-printed aligners using different post-polymerisation conditions.</p>
</sec>
<sec>
<h3>Materials</h3>
<p>Aligners were printed using the same 3D-print resin (TC-85DAC, Graphy, Seoul, Korea) and printer (AccuFab-L4D, Shining 3D Tech. Co., Hangzhou, China), followed by different post-curing procedures. Six aligners were post-polymerised for 14 min using the Tera Harz Cure and a nitrogen generator curing machine (THC2, Graphy, Seoul, Korea) (P1). A further six aligners were post-cured for 30 min on each side using the Form Cure machine (FormLabs Inc, Somerville, USA) (P2). The aligners were cut into smaller specimens (2 mm×2 mm) and sterilised at 121°C. The specimens were placed in 96-well plates containing Dulbecco’s Modified Eagle’s Medium (DMEM) at 37° for 7 or 14 days. The viability of MC3T3E-1 pre-osteoblasts cultured with DMEM was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The optical density of each cell culture was measured to assess cell viability, following which the data were statistically analysed using two-way and one-way ANOVA (α = 0.05).</p>
</sec>
<sec>
<h3>Results</h3>
<p>The comparison of cytotoxicity revealed statistically significant differences between post-curing procedures and MTT timings (<italic>P</italic> &lt; 0.001). After 7 and 14 days, the cell viability of P2 was significantly reduced compared to P1 and the control groups (<italic>P</italic> &lt; 0.001), while P1 showed no significant differences compared to the controls. Overall, P2 post-curing exhibited moderate cytotoxicity, while P1 post-polymerisation was highly biocompatible.</p>
</sec>
<sec>
<h3>Conclusions</h3>
<p>Different post-curing procedures may affect the in-vitro cytotoxicity of 3D-printed aligners. Clinicians should adhere to the manufacturer’s recommendations when using 3D-print resin.</p>
</sec>
</abstract>

Objective
Three-dimensional (3D) printing technology represents a novel method for manufacturing aligners. The aim of the present study was to assess the in-vitro cytotoxicity of 3D-printed aligners using different post-polymerisation conditions.


Materials
Aligners were printed using the same 3D-print resin (TC-85DAC, Graphy, Seoul, Korea) and printer (AccuFab-L4D, Shining 3D Tech. Co., Hangzhou, China), followed by different post-curing procedures. Six aligners were post-polymerised for 14 min using the Tera Harz Cure and a nitrogen generator curing machine (THC2, Graphy, Seoul, Korea) (P1). A further six aligners were post-cured for 30 min on each side using the Form Cure machine (FormLabs Inc, Somerville, USA) (P2). The aligners were cut into smaller specimens (2 mm×2 mm) and sterilised at 121°C. The specimens were placed in 96-well plates containing Dulbecco’s Modified Eagle’s Medium (DMEM) at 37° for 7 or 14 days. The viability of MC3T3E-1 pre-osteoblasts cultured with DMEM was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The optical density of each cell culture was measured to assess cell viability, following which the data were statistically analysed using two-way and one-way ANOVA (α = 0.05).


Results
The comparison of cytotoxicity revealed statistically significant differences between post-curing procedures and MTT timings (P < 0.001). After 7 and 14 days, the cell viability of P2 was significantly reduced compared to P1 and the control groups (P < 0.001), while P1 showed no significant differences compared to the controls. Overall, P2 post-curing exhibited moderate cytotoxicity, while P1 post-polymerisation was highly biocompatible.


Conclusions
Different post-curing procedures may affect the in-vitro cytotoxicity of 3D-printed aligners. Clinicians should adhere to the manufacturer’s recommendations when using 3D-print resin.

Comparison of the cytotoxicity of 3D-printed aligners using different post-curing procedures: an in vitro study

Australasian Orthodontic Journal

This work is licensed under the Creative Commons Attribution 4.0 International License.

Objective
Three-dimensional (3D) printing technology represents a novel method for manufacturing aligners. The aim of the present study was to assess the...

Comparison of the cytotoxicity of 3D-printed aligners using different post-curing procedures: an in vitro study

Pubblicato online: 14 ago 2023

Pagine: 49 - 56

Ricevuto: 01 feb 2023

Accettato: 01 lug 2023

DOI: https://doi.org/10.2478/aoj-2023-0026

© 2023 Campobasso Alessandra et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.