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Purpose: To evaluate the effect of model resin type and time interval on the dimensional stability of additively manufactured diagnostic casts.Materials and Methods: Ten irreversible hydrocolloid impressions and 10 impressions from an intraoral scanner were made from a reference maxillary stone cast, which was also digitized with a laboratory scanner.Conventional impressions were poured in type III stone (SC), while digital impressions were used to additively manufacture casts with a nanographene-reinforced model resin (GP) or a model resin (DM).All casts were digitized with the same laboratory scanner 1 day (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) after fabrication.Cast scans were superimposed over the reference cast scan to evaluate dimensional stability.Data were analyzed with Bonferroni-corrected repeated measures ANOVA (α = .05).Results: The interaction between the main factors (material type and time interval) affected anterior teeth deviations, while the individual main factors affected anterior teeth and entire-cast deviations (P ≤ .008).Within anterior teeth, DM had the lowest deviations at T3, and GP mostly had lower values at T2 and lower deviations at T3 than at T0 (P ≤ .041).SC had the highest pooled anterior teeth deviations, and GP had the highest pooled entire cast deviations (P < .001).T3 had lower pooled anterior teeth deviations than at T0, T1, and T4, and higher pooled entire cast deviations than T1 were demonstrated (P ≤ .027).Conclusions: The trueness of nanographene-reinforced casts was either similar to or higher than that of other casts.Dimensional changes were acceptable during the course of 1 month.
Dönmez et al. (Wed,) studied this question.