Çeşitli Geçici Kron Materyallerinin Mekanik ve Fiziksel Özelliklerinin in-Vitro Karşılaştırılması
Özet
It is important for patient comfort and satisfaction that provisional restorations should not fracture, get deformed and show discoloration while in use. In our study, 6 different provisional restoration materials were subjected to microhardness test and flexural test in order to measure mechanical strength, surface roughness test and discoloration test in order to evaluate esthetics. With the help of these tests, we searched for materials that are advantageous during clinic use. Vita CAD-Temp and Ivoclar Telio-CAD blocks for CAD/CAM are used in our study. Other materials used in our study are Revotek LC (UDMA), Protemp 4 (Bis-akril), Dentalon Plus (PEMA) and İmident (PMMA). Samples for 3-point bending test are manufactured with dimensions 2 x 2 x 25 mm according to ISO 4049 (n=15). Samples were loaded with a universal testing machine until fracture occurred. For microhardness, surface roughness and discoloration tests, disc shaped samples with 10 mm diameter and 2 mm thickness were manufactured (n=15). Baseline color measurements were made after Vickers microhardness and surface roughness tests. As a coloring agent, coffee was chosen. All samples were immersed in coffee solution for 7 days. Second color measurements were made. ΔE values, which shows discoloration, were calculated. Statistical analysis of the data was made with SPSS for Windows 11.5. Kruskal Wallis test was used in order to evaluate level of significance (p<0,05). Flexural strength values varied between 146 MPa and 63 MPa. The most strong groups were İmident and Protemp 4. Microhardness and surface roughness evaluation showed methacrylate resins are better than other groups. As color stability, PMMA groups were found to discolor less than other groups. Revotek LC and Protemp 4 showed clinically unacceptable ΔE values (ΔE>3.3). Based on this study data, it is advised to use heat polymerized PMMA when long-term use is indicated.
