The effect of type of material and method of construction on the fracture toughness of different commercially available provisional restoration resins

Abstract

Purpose : to assess the most suitable resin restoration and methods of construction according to the fracture toughness as a provisional restoration among Bis-acryl resin (self-cure), Rubberized-Urethane resin (dual cure), CAD/CAM PMMA (VITA CAD-Temp), CAD/CAM PMMA (breCAM. multiCOM). Methods: A total of 40 specimens were constructed for this in vitro study. The specimens were divided into 2 groups according to the method of construction; manually fabricated group (M) and CAD/CAM group (C) (n=20 for each group). A split mold was specifically constructed for this in vitro study. The mold was constructed from Teflon material. The speciments of each group were prepared with dimensions (3 x 4 x 14) mm A notch was milled in the middle of each specimen by microsaw machine. The 3-point bending test was carried out using universal testing machine (loud cell 500 N). The fracture toughness data of each type of provisional material was tabulated and analyzed. The fractured surface morphology was captured using Scanning Electron Microscope (SEM). Results: The 4 products were compared using ANOVA test. The greatest mean was recorded in breCAM.multiCOM group (B) (1.074±0.195), whereas the lowest mean was recorded in Tuff-Temp group (T) (0.6437±0.167). Tukey's post hoc test revealed no significant difference between Protemp 4 group (P), VITA CAD Temp group (V) and breCAM.multiCOM group (B). These 3 groups recorded significantly higher mean values in comparison to Tuff Temp group (T) CAD/CAM group (C) (1.0134±0.157) recorded higher mean value the manual group (M) (0.8459±0.275). The difference between the 2 construction methods was statistically significant (P=0.025) Conclusion: the first part of the null hypothesis was rejected because not all products recorded significantly different fracture toughness mean values. Also the second part of the null hypothesis was rejected because not all CAD/CAM provisional crowns demonstrated superior fracture toughness to that of conventional provisional materials.

The Effect of Aging on Surface Roughness of Provisional Crown and Bridge Material

“…For example, in anterior esthetic rehabilitation, the esthetic necessity is much more essential than in posterior esthetic rehabilitation. Provisional components used in malocclusion correction and vertical dimension rising cases must also have excellent mechanical properties, (5) . Poly methyl-methacrylate and ethyl methacrylate resins, polyvinyl-methacrylate resins, compositebased resins, or urethane-based resins are examples of temporary light-curing or auto-polymerizing resin-based materials.…”