Comparison of Flexural Strength of 3D-Printed Provisional Restorative Resin according to Immersion Time in Korean Traditional Sauces

This study evaluates and compares the flexural strength of 3D-printed provisional restorative resin, produced according to ISO 20795-1:2013 standards, based on the immersion time in Korean traditional sauces(soy sauce, soybean paste, red pepper paste). This comparison aims to provide meaningful data that can contribute to improving the quality of temporary prosthetics functioning in the oral environment. Bar-shaped specimens (65 × 10 × 3.3 mm) were fabricated using a 3D printer with a provisional restorative resin. The specimens were divided into four groups: a control group and three experimental groups (soy sauce, soybean paste, and red pepper paste). Each group was further subdivided according to the immersion periods of 5 and 10 days. After each immersion period, the flexural strength was measured using a universal testing machine (UTM) with a three-point bending test. The flexural strength of the 3D-printed provisional resin varied significantly depending on the immersion time and the type of Korean traditional sauce(p<.05). After 5 days of immersion, the red pepper paste group showed the highest strength(149.08±6.25), while the soybean paste group showed the lowest (138.61±13.79). All experimental groups showed significant differences compared to the control group, although no significant differences were observed among the different types of sauces. After 10 days of immersion, the soy sauce group exhibited the highest strength(115.01±6.61), and the red pepper paste group showed the lowest(106.96±8.17). Significant differences were observed in all groups, except between the soybean paste and red pepper paste groups. Furthermore, a comparison of flexural strength according to immersion time for each sauce revealed statistically significant differences in all groups (p<.05). Within the limitations of this study, the flexural strength of 3D-printed provisional restorative resins is significantly affected by the type of Korean traditional sauces and the duration of exposure. When using 3D-printed provisional restorations for a long period, clinicians should consider the potential degradation of mechanical properties due to the patient’s dietary habits, especially regarding high-salinity fermented sauces.