Effect of different definitive restoration resins and postpolymerization durations on the trueness of 3D printed one-piece endodontic crowns

Abstract

Statement of problem: Because of the multivariable nature of the 3-dimensional (3D) printing process, each stage must be performed under optimal conditions to ensure the trueness and reliability of dental restorations. However, information regarding the effect of postpolymerization on the trueness of resins with different filler compositions is limited and nonstandardized. Purpose: The purpose of this in vitro study was to evaluate the effect of postpolymerization durations on the trueness of 1-piece endodontic crowns fabricated from definitive restoration resins with varying filler content. Material and methods: A digital definitive cast of a mandibular first molar with a 1-piece endodontic crown preparation was designed with a computer-aided design software program and saved as the reference. The reference design was processed in a slicing software program and prepared for printing with appropriate settings based on the material specifications. The study groups consisted of 3 different definitive restoration resins: VarseoSmile Crown Plus (VS), P-Crown Version 3 (PC), and Saremco Print Crowntec (CR). Each resin group was subdivided into 3 postpolymerization durations, resulting in a total sample size of n=20 per group (1-?=80%, effect size of f=0.30, ?=.05). One-piece endodontic crowns were fabricated, and final polymerization was carried out under a 0.15 MPa nitrogen atmosphere using 3 different postpolymerization cycles (2000, 4000, and 6000 flash). The fabricated specimens were digitized with an intraoral scanner, and each scan was superimposed with the reference definitive cast. Surface deviations were analyzed through root mean square (RMS), mean positive and negative deviations, and total match percentages. Data were analyzed with the ANOVA and Tukey significant difference tests (?=.05) Results: Variations in postpolymerization duration did not result in statistically significant differences in the trueness of the 1-piece endodontic crowns fabricated from any of the evaluated resins (P>.05). Regardless of postpolymerization duration, statistically significant differences were found among the resin groups in terms of trueness parameters, including RMS values, mean positive and negative deviation values, and total match percentages (P<.05) Conclusions: Trueness was not significantly affected by postpolymerization duration but was significantly influenced by the type of resin material, which was associated with different filler compositions. © 2025 Editorial Council for The Journal of Prosthetic Dentistry