ISSN : 0376-4672
Purpose : The purpose of this study is to compare flexural strength according to the thickness of provisional restoration materials manufactured by subtractive and additive methods using CAD-CAM system. Materials and methods : It was divided into three groups with different manufacturing methods, the CON group manu factured by the traditional method, the MIL group manufactured by subtractive methods and the DLP group manufactured by additive methods. Each group was divided into 3 groups by varying the thickness of the specimen (1.0 mm, 1.5 mm, 2.0 mm), and a total of 9 experimental groups were set. Fifteen specimens for each group were prepared in the form of a bar and the flexural strength was measured. Results : According to the manufacturing method, the MIL group showed the highest flexural strength, followed by the DLP group and the CON group(p<0.01). In the MIL and DLP groups, the flexural strength increased statistically significant ly as the thickness increased (p<0.01), but in the CON group, there was no statistically significant difference in the flexural strength at 1.5 mm thickness and 2.0 mm thickness(p>0.05). Conclusion : Provisional restorative resins fabricated by subtractive methods showed higher flexural strength than those made by additive manufacturing, and both showed superior flexural strength than those fabricated by traditional methods. Active use of the CAD-CAM system in the dental field is recommended, however, as the flexural strength decreases sta tistically as the thickness of the material decreases, we need to be careful about reduction in the thickness of the material.
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