Context: There is presently no ideal provisional material suitable for all clinical conditions. A material for the fabrication of multiunit interim prostheses for longer duration of time it can be reinforced with different materials. Which materials is best for increasing the fracture toughness of material is unclear, therefore it is necessary to evaluate effect of different reinforcements and the best material suitable for increasing the fracture toughness of provisional materials. Purpose: The aim of the study was to evaluate and compare the fracture toughness of chemically cure and dual cure interim fixed partial denture materials with different methods of reinforcement. Methodology: A stainless steel jig was fabricated with standard specifications. A urethane based dual cure resin (Tuff temp plus) and bis acryl based self cure (Protemp 4) interim restorative materials were used for fabrication of samples. Glass fibers, Braided glass fibers, graphene oxide nanoparticles and stainless steel mesh were used as reinforcement materials. Total 100 samples were fabricated and divided according to interim restorative resins used. Samples were further divided into five subgroups of each group having 10 with each reinforcing material. Unreinforced samples were fabricated as control groups. The fracture toughness values for each sample were measured using Universal testing machine (Dak system inc, series 7200). Statistical analysis: ANOVA test, Tukey’s post hoc test. Result: All the reinforcements have shown statistically significant increase in fracture toughness values for both the groups. Among all the reinforcements for group I (Tuff temp plus) statistically significant fracture toughness values were obtained with graphene nano particles (519.5±109.91), stainless steel mesh (505.1±108.15), braided glass fibers (382.23±32.3) and Glass fibers (374.9±75.08) in comparison to control group (P<0.05). Whereas for group II all the reinforcements, graphene nanoparticles (574.7±111.86), stainless steel mesh (561.7±28.44), braided glass fibers (443.2±130.05) and glass fibers (426.6±111.86) showed statistically highly significant values in comparison to control group (P<0.05). No significant difference was observed in comparison of fracture toughness between group I and group II control and reinforced specimens. Conclusion: When compared to control groupall the reinforcement materials produce significantly higher fracture toughness for both UDMA resin (Tuff temp plus) and bisacryl (Protemp 4).Reinforcement of both types of resin with graphene oxide nanoparticles and stainless steel mesh provides higher fracture toughness in comparison to glass fibers and braided glass fibers. No statistically significant difference was evident between UDMA and bisacryl resin.