Statement Of Problem Recent advances in dental additive manufacturing have introduced plant-based resins for casts and alcohol-free cleaning solutions; however, their suitability for producing dimensionally accurate and stable removable dies remains unclear.Purpose The purpose of this in vitro study was to assess the dimensional and positional deviations and 4-week stability of additively manufactured removable dies made from 2 plant-based and 1 dental cast resins, cleaned with methyl ether solvent (MES), isopropyl alcohol (IPA), or a water-based solution (WBS).Material And Methods A typodont with a prepared right first mandibular molar was digitized to design removable dies and hollow partial arch casts. Fifty-four dies (N=18) and 9 casts (N=3) were fabricated from 3 resins: Soy-Based Resin (EX), FotoDent biobased model (FD), and KeyModel Ultra Ivory (KM). Specimens were divided into 3 subgroups by cleaning solution; MES, IPA, and a WBS (n=6 dies, n=1 cast). Dies and their corresponding seated casts were digitized at 1 day (T0) and at 1-week intervals up to 4 weeks (T1-T4) after fabrication. Trueness was assessed from the surface deviations of die regions (crown, root, and root base) and positional deviations within casts at T0, while T0-T4 deviations evaluated stability. T0 deviations were assessed with a generalized linear model, while those over time were evaluated with linear mixed-effects models (α=.05).Results Resin type-cleaning solution interaction influenced the dimensional and positional deviations at T0 (P≤.049). In addition, crown region deviations were influenced by resin type-cleaning solution and resin type-time point interactions, whereas other surface and positional deviations were affected by interactions among all main factors (P≤.005). FD dies and MES-cleaned dies mostly had lower surface deviations, while IPA-cleaned FD dies had the lowest positional deviations (P≤.040).Conclusions FD resin dies generally showed higher dimensional trueness and stability, while MES-cleaning also increased the dimensional trueness and stability of tested dies. IPA-cleaned FD dies exhibited the highest positional trueness and stability. The effect of the time point on deviations was minimal and likely clinically negligible.
Donmez et al. (Thu,) studied this question.