| dc.description.abstract | Statement of problem. There are no published data about the storage guidelines for the 3D printed occlusal devices.
Purpose. The objective of this in vitro study is to investigate the dimensional stability of the 3D printed occlusal device, stored under different conditions.
Material and methods. Maxillary and mandibular dental models were scanned and exported in STL form to 3D print 40 occlusal devices. The specimens were stored under three different storage conditions (n=10); group DL air-dried and stored under natural light, group W stored in a dark box, and group D air-dried and placed in a dark box. The intaglio surfaces of the occlusal devices were scanned by a laboratory scanner in four-time intervals as follows: right after post-curing process of the 3D printed appliance at 0 hours (t0, control), after 1 day (t1), after 7 days (t2) and after 27 days (t3). The dimensional changes of whole internal surfaces between t0 and t1 (Δt1), t0 and t2 (Δt2), t0 and t3 (Δt3) were measured by best fit algorithm in computer-aided designing software. In addition, comparison among different areas such as the posterior and anterior sections was performed. Statistical analysis was completed with Kolmogorov- Smirnov, one-way ANOVA, Friedman, Kruskal- Wallis and Mann-Whitney, unpaired t-test.
Results. The root mean square (RMS) of group DL between Δt1 and Δt2, and between Δt1 and Δt3 showed statistically significant difference (P<.05). The RMS of group W between Δt1 and Δt3 showed statistically significant difference (P<.05). When the groups were compared with each other at the different time intervals group, DL group showed statistically significant (P<.05) difference compared to groups W and D at Δt1. The examination of different areas of the occlusal device (right molars site, incisors site, left molars site) indicated that there was no statistically significant difference in RMS among different areas for all groups (P>.05).
Conclusions: The occlusal devices stored under natural light showed the least dimensional change at Δt1 which was statistically significant (P<.05) compared to W and D. However, at Δt2 and Δt3 the dimensional change of the different groups was not statistically significant, indicating that the storage method does not clinically affect the fit of the occlusal device. When the dimensional change among the different locations was compared, there was no significant differences among the three different locations, for all groups after 27 days. | en |
