Evaluation of flexural strength and surface hardness of heat activated provisional PMMA resin reinforced with nanoparticles-an in vitro study

Abstract

The provisional restorations are subjected to vertical, lateral and horizontal forces during function, hence the mechanical properties of the provisional materials to be taken into account before choosing for clinical use. The objectives of the study were to evaluate and compare the flexural strength and surface hardness of heat polymerized provisional polymethylmethacrylate resin reinforced with 2.5% Zirconia, Titanium or Aluminum oxide nano-particles. According to ISO 10477:2018, die was made in 25 mm x 2 mm x 2mm for flexural strength and wheel die in 15 mm diameter and 1mm thickness for hardness test. A total of 160 samples were fabricated and divided into Groups. I- (samples kept in distilled water for 24 hours after fabrication) and Group. II (samples kept in artificial saliva for 2 weeks after fabrication) and subdivided into Group-a(control), samples reinforced with 2.5% Zirconia nanoparticle (Group b), samples reinforced with 2.5%Titanium oxide nanoparticles (Group c), samples reinforced with 2.5% Aluminum oxide nanoparticles (Group d). The flexural strength was evaluated by three-point bending test and the hardness was evaluated using digital Vickers micro hardness tester. The values were statistically analyzed using one way ANOVA and Tukey’s HSD test at significant level P<0> Keywords: Flexural strength, Heat activated PMMA resin, Provisional restoration, Surface hardness.