Biaxial flexural strength of different provisional restorative materials under chemo-mechanical aging: An in vitro study

PurposeDurability is a critical factor for the success of long-term provisional restorations. This study evaluated the effect of different storage media and cyclic loading on the biaxial flexural strength of different types of provisional materials. Materials and methodsDiscs (N = 360, 10 x 2 mm) were prepared from different provisional materials; conventional (Protemp 4, Tuff-Temp, Tempron), CAD-CAM milled (VITA CAD-Temp, breCAM.multiCOM), and 3D-printed (Nextdent C&B MFH) (n = 60). Each material group was subdivided into four subgroups according to the storage media (n = 15): nonaged, artificial saliva, mouthwash, and coffee. The specimens in storage media were placed in an incubator at 37 degrees C for 4 weeks followed by 60,000 simulated chewing cycles. Biaxial flexural strength test was done. Data were analyzed using two-way ANOVA. Weibull distribution parameters were estimated. ResultsBoth the material and aging protocol showed a significant effect on the biaxial flexural strength. Both Protemp 4 and Nextdent C&B MFH showed a significantly higher biaxial flexural strength before and after aging compared to all other materials. Protemp 4 and Tuff Temp showed a significant decrease in strength with aging. CAD-CAM materials showed higher Weibull moduli. ConclusionsThe 3D-printed polymethylmethacrylate provisional material presents with both greater biaxial flexural strength and increased durability against chemical and mechanical aging compared to conventional and CAD-CAM milled provisional materials tested.