(1) Background: This study aimed to compare the shaping abilities of modern minimally invasive endodontic systems using natural teeth and 3D-printed resin replicas. These replicas offer a standardized approach for studying root canal preparation while eliminating the variability and scarcity of natural teeth. (2) Methods: Eleven mandibular molars with Vertucci class IV anatomy and their 3D-printed replicas (n = 132 canals) were scanned using micro-CT before and after preparation with six rotary systems. Shaping abilities were assessed by comparing volume, surface area, and unprepared areas between natural teeth and their 3D replicas, focusing on the apical third. Statistical analysis included the Shapiro–Wilk test to assess data normality and ANOVA and t-tests to compare different endodontic systems. (3) Results: Both qualitative and quantitative analyses revealed high similarity between natural teeth and 3D replicas. No significant differences in volume or surface area were found except in the apical third, where 3D replicas showed slightly larger increases in volume. (4) Conclusions: 3D resin replicas closely mimic natural teeth and provide a practical tool for assessing the shaping abilities of endodontic systems. This study demonstrates that 3D-printed models are suitable for endodontic research, offering a standardized and accessible alternative to natural teeth.

Durante la pandemia del Covid-19, a raíz del distanciamiento social, se han tenido que cambiar los espacios tradicionales de aprendizaje, como son las aulas, clases y laboratorios, por los espacios virtuales que permiten la no presencia física. Todo ello ha acelerado la docencia online en las diferentes áreas del conocimiento y por lo tanto, también en odontología. Gracias a los diferentes dispositivos electrónicos y al acceso a internet, se han desarrollado espacios interactivos multimedia que han permitido una mayor flexibilidad y accesibilidad en el aprendizaje. Pero, este modelo de aprendizaje online no está exento de problemas. Cabe destacar, principalmente, el inconveniente de garantizar la motivación de los estudiantes, así como la ausencia de prácticas clínicas con pacientes

Objective: This study investigated the shaping efficiency of four reciprocating systems—WaveOne Gold, Reciproc Blue, Excalibur, and One Reci—in three dimensional (3D) resin models of natural mandibular premolar teeth with two canals. Methods: Forty 3D-printed mandibular premolars (Vertucci configuration type V) were divided into four groups, each of which was assigned one of the reciprocating systems. According to the manufacturer’s protocols, each canal was prepared, with pre- and post-instrumentation micro computed tomography (micro-CT) scans evaluating canal volume, surface area, percentage of unprepared canal walls, and resin reduction in the pericervical area. Instrumentation time and screw-in sensation were recorded as qualitative performance indicators. Statistical analysis was performed using one-way ANOVA and chi-square tests with a significance of (p < 0.05). Results: All systems increased canal volume and surface area, primarily in the apical third, with Reciproc Blue and One Reci achieving the largest volume. WaveOne Gold had the highest percentage of unprepared walls (27.03%) and Reciproc Blue the lowest (19.65%), though these differences were not statistically significant (p > 0.05). Reciproc Blue caused the highest pericervical resin loss (22.24%), significantly higher than Excalibur (15.09%) and One Reci (15.17%) (p = 0.035). Reciproc Blue exhibited the highest incidence of screw-in sensation (70%), while WaveOne Gold achieved the shortest instrumentation time (86.7 s), although neither variable showed statistical significance. Conclusions: All systems effectively shaped complex canal anatomies, with Reciproc Blue demonstrating the highest dentin removal and WaveOne Gold proving the most time efficient. Clinically, these findings suggest that instrument selection should balance shaping efficiency with dentin preservation. Minimizing unprepared areas and preserving pericervical dentin are essential for enhancing disinfection and reducing the risk of root fractures, ultimately contributing to the long-term success of endodontic treatment.