Impact of plant-based resins and alcohol-free cleaning solutions on the dimensional stability of additively manufactured dental casts.

Objective
This study aimed to evaluate the dimensional stability of additively manufactured dentate casts over one month by comparing plant-based dental cast resins and alcohol-free cleaning solutions to a conventional resin and isopropyl alcohol (IPA).Methods
The standard tessellation language (STL) file of a maxillary dentate model was used to fabricate 60 casts from three plant-based resins (Plant-based resin gray, AC; Soy-based resin, EX; FotoDent biobased model, FD) and one conventional resin (KM, KeyModel Ultra Ivory) (N = 15). The casts were cleaned using either isopropyl alcohol (IPA), methyl ether solvent (MES), or a water-based solution (n = 5). All casts were digitized one day post-fabrication and weekly thereafter for one month (T0-T4). The master STL and cast scans were imported into a metrology-grade software program for deviation analysis. Dimensional deviations were analyzed using a generalized linear model (α = 0.05).Results
Across tested cleaning solutions and storage durations, KM casts mostly had the lowest and EX casts mostly had the highest deviations (P < 0.001). IPA mostly led to lower and the water-based solution mostly led to higher deviations (P ≤ 0.045). Storage duration significantly affected AC casts and those cleaned with MES, with mostly higher deviations at T0 (P ≤ 0.018). IPA-cleaned casts mostly showed lower deviations across time points (P ≤ 0.043).Conclusions
KM and FD resins demonstrated greater dimensional stability than AC and EX resins. IPA cleaning preserved dimensional stability most effectively, followed by MES. Storage duration had minimal impact on casts' dimensional stability.Clinical Significance
Regardless of the cleaning solutions used in this study, tested plant-based resins, particularly the corn-based formulation, may serve as ecologically sustainable alternatives to conventional resin for diagnostic and orthodontic casts, maintaining one-month dimensional stability. Additionally, alcohol-free cleaning solutions may enhance the environmental sustainability of casts fabricated from conventional resin.