Effects of the Washing Time and Washing Solution on the Biocompatibility and Mechanical Properties of 3D Printed Dental Resin Materials

Abstract

Three-dimensional (3D) printing technology is highly regarded in the field of dentistry. Three-dimensional printed resin restorations must undergo a washing process to remove residual resin on the surface after they have been manufactured. However, the effect of the use of different washing solutions and washing times on the biocompatibility of the resulting resin restorations is unclear. Therefore, we prepared 3D-printed denture teeth and crown and bridge resin, and then washed them with two washing solutions (isopropyl alcohol and tripropylene glycol monomethyl ether) using different time points (3, 5, 10, 15, 30, 60, and 90 min). After this, the cell viability, cytotoxicity, and status of human gingival fibroblasts were evaluated using confocal laser scanning. We also analyzed the flexural strength, flexural modulus, and surface SEM imaging. Increasing the washing time increased the cell viability and decreased the cytotoxicity (p < 0.001). Confocal laser scanning showed distinct differences in the morphology and number of fibroblasts. Increasing the washing time did not significantly affect the flexural strength and surface, but the flexural modulus of the 90 min washing group was 1.01 ± 0.21 GPa (mean ± standard deviation), which was lower than that of all the other groups and decreased as the washing time increased. This study confirmed that the washing time affected the biocompatibility and mechanical properties of 3D printed dental resins.

Biocompatibility enhancement via post-processing of microporous scaffolds made by optical 3D printer

“…Post-processing methods involving prolonged soaking in organic solvents (e.g., isopropanol, methanol) allow the unpolymerized monomers in the inner layers of the structure to be reached and washed out. Previous studies have shown a positive correlation between cell viability and scaffold washing time ( Grigaleviciute et al, 2020 ; Hwangbo et al, 2021 ). In addition, washing of the specimens in an ultrasonic bath was shown to improve cell proliferation significantly ( González et al, 2020 ).…”

“…Among the techniques proposed for the fabrication of scaffolds, precise control of the scaffold structure can be provided by photopolymerization methods such as Laser Driect Writing (LDW) ( Danilevicius et al, 2012 ; Weisgrab et al, 2020 ; Sharaf et al, 2022 ), Stereolithography/Direct Light Processing (SLA/DLP) ( González et al, 2020 ; Hart et al, 2020 ; Ao-Ieong et al, 2021 ; Bayarsaikhan et al, 2021 ; 2022 ; Hwangbo et al, 2021 ), holographic lithography ( Stankevicius et al, 2012 ) and others. SLA and DLP are the two most widely used technologies in commercial UV desktop printers.…”

Design, fabrication, and evaluation of functionally graded triply periodic minimal surface structures fabricated by 3D printing

“…The resin has a density of 1.10 g/ cm 3 and a tensile modulus of elasticity of 1.05 GPa [45] which is suitable for general modeling and industrial prototype proofing. Next, the printed samples were cleaned using ethyl alcohol at 70% concentration with a washing time of 3 min [46,47]. The structures were built with external supports with cylindrical shape and conical connection that were removed manually by pliers.…”

Assessment of Biocompatibility of 3D‐Printed Cardiovascular Stent

“…[11] The biocompatibility of the resource material in biomedical devices could be dependent on the amount of the active components, physical properties, and the duration of the study. [31,32] The toxicological assessment of the biomedical products including 3D-printed cardiovascular stents could provide critical insights into post-treatment strategies to minimize the material-related adverse effects and reduce the associated risks in patients during their clinical application, [33] subsequently facilitating the regulatory preapproval process. [34] An assessment of therapeutic efficacy and biocompatibility of nanomaterial-based materials including hydrogels seems to be integral for the successful development of biomedical devices, especially for cardiovascular application including devices against atherosclerosis, [20] tissue/muscle regeneration in myocardia infection, [35] and activation of cardiac fibroblasts that is a pathological, phenotypic transition in cardiac fibrosis.…”