Objective: To compare the reproduction trueness and precision of dental casts made by the conventional, milling and 3D printing techniques. Material and Methods: From an upper right side half-arch reference model (RM), 72 models were obtained and divided into three groups: conventional (CM), milled (MM) and printed (PM). All models were scanned and converted into standard tessellation language (.STL) files. The files were superimposed using 3D analysis software, and statistical analysis was performed using the root mean square (RMS) values obtained. The Shapiro-Wilk test was used to assess normality, and the Kruskal-Wallis test was used to compare groups (ρ < ⍺; ⍺ = 0.05). The Mann-Whitney U test was used for multiple comparisons among groups (ρ < ਕ; ਕ = 0.017). Results: There were significant differences in trueness (ρ = 0.000; ρ <0.001) and precision (ρ = 0.000; ρ < 0.001) among the three dental cast groups. Regarding trueness, CM presented better results, followed by MM and PM. Regarding precision, MM showed better results, followed by PM and CM, which did not show significant differences. Conclusions: For dental cast reproduction the conventional technique has the best trueness and the milling technique has the best precision.

Objective: This study retrospectively correlated metallic cast retainers’ length with the quality of the remaining apical sealing. Methods: A total of 320 periapical radiographs were analyzed by two independent, calibrated examiners. The retainers’ length was classified as adequate, short, and long (2/3, <2/3, and >2/3 of the root length, respectively). The quality of the remaining apical sealing was assessed considering three aspects: lateral compaction, distance to the root apex, and amount of remaining filling material. A chi-square test at a 5% significance level was used for statistical analysis. Results: Of the 443 intracanal retainers assessed, 14.9% were adequate, 82.4% short, and 2.7% long. Regarding endodontic treatment aspects, 76.1% were inadequate in at least one aspect, whereas approximately 50% were incorrect in all aspects analyzed (p=0.0003). When both prosthetic and endodontic aspects were considered, 5.9% of the treatments were considered appropriate, 16.9% clinically acceptable, and 77.2% inadequate. Conclusions: Suitable retainers were 2.5 times more frequent in teeth with adequate endodontic treatment. The low frequency of appropriate intracanal retainers suggests inappropriate endodontic treatment.