Influence of the printing technologies, storage conditions, and storage time on the intaglio surface accuracy of additively manufactured edentulous surgical guides: An in vitro study.

Purpose: To evaluate the effects of printing technologies, storage conditions, and storage time on the intaglio surface accuracy of additively manufactured maxillary edentulous surgical guides.

Materials and methods: Forty-eight maxillary edentulous surgical guides were fabricated using three different printing technologies (n = 16): DLP (digital light processing), PJ (polyjet), and SLA (stereolithography). After postprocessing, each group was randomly divided into 2 storage conditions: dark storage (D) and light exposure storage (L). The intaglio surface of each specimen was scanned by a laboratory scanner on storage days 0, 3, 7, 14, and 28, respectively. The digital design file served as the reference, and each digitized specimen was superimposed onto the reference file using a 3-dimensional (3D) analysis software program. The root mean square (RMS) error was used to calculate trueness. The percentage of measurement data points within 1 standard deviation was used to demonstrate precision. Repeated-measures ANOVA was used to analyze the data (α = 0.05).

Results: Printing technologies (p < 0.001) and storage time (p < 0.001) significantly affected the intaglio surface accuracy of additively manufactured maxillary edentulous surgical guides. The DLP group exhibited the best printing accuracy at Day 0, with a significant decline in accuracy from Day 0 to Day 28. On the contrary, the PJ group and SLA group demonstrated superior stability during the 1-month storage. No statistical significance was found between dark storage and light exposure groups (p > 0.05).

Conclusion: Group DLP had the highest accuracy after manufacturing. Storage time only affected the accuracy of group DLP. Storage conditions had no effect on the three groups tested.