A comparative evaluation of effect of reinforced autopolymerizing resin on the flexural strength of repaired heat-polymerized denture base resin before and after thermocycling

Abstract

Aims and Objective:Denture fractures are a common problem in clinical practice. Despite the use of different reinforcement materials (metal wires, metal plates, and various types of fibers) for denture repairs, recurrent fractures are still common. The purpose of this study was to compare the maximum flexural loads of the heat-polymerized denture base resin when repaired with autopolymerizing resin reinforced with relatively smaller diameter metal wires and glass fibers, before and after thermocycling.Materials and Methods:Heat polymerized rectangular specimens were fabricated and repaired with autopolymerized resin and different reinforcement materials. Stainless steel wires, coaxial wires, beta-titanium wires, and glass fibers were used as reinforcement materials. Metal wires were sandblasted before placing in the center of the specimen along with autopolymerizing resin. Control specimens were repaired without any reinforcements. Intact heat- and self-cure specimens were also prepared for comparison. Half of the specimens of each group were subjected to thermocycle stressing (5°C and 55°C, 30 s dwell time) for 2000 cycles. All the specimens, nonthermocycled as well as thermocycled, were then tested for flexural strength by using 3 point flexural test in Lloyd's Universal testing machine at 5 mm/min crosshead speed. The maximum flexural loads (N) for each specimen were recorded. The readings, thus obtained, were subjected to statistical analysis using two-way ANOVA and Tukey's multiple comparison test.Results:The metal wire reinforcements increased the flexural strength of repaired specimens, whereas, glass fiber reinforcement produced slightly lower flexural strength when compared to those of control specimens, i.e., repair without any reinforcement. The highest flexural strength was demonstrated by specimens repaired with coaxial wire reinforcements (50.01 and 43.77 N before and after thermocycling, respectively). The increase in flexural strength with the use of stainless steel wire (45.12 and 41.56 N) and beta-titanium wire reinforcements (45.54 and 42.61N) was insignificant.Conclusions:Coaxial wire reinforcement produced significantly higher flexural loads than control. Increase in strength with stainless steel wire and beta-titanium wire was insignificant, whereas glass fiber reinforcement reduced the strength.

Effect of Antibacterial Silver-Releasing Filler on the Physicochemical Properties of Poly(Methyl Methacrylate) Denture Base Material

“…Other material properties that affect the durability of PMMA dentures are their hardness and wear resistance which determine the surface conditions of prosthetic materials [43,44]. The significance of the abovementioned properties is demonstrated by a significant number of studies on their changes in the context of various aspects of the functioning of materials such as the use of cleaning agents or the consumption of hot/cold foods and drinks (thermocycling) [22,45]. Considering that these materials function in an environment with 100% humidity, their behavior under these conditions is equally important, not only in the context of mechanical/tribological properties, but also due to the fact of water absorption and release of material components into the environment.…”

Evaluation of flexural properties and dynamic mechanical analysis of glass fiber-reinforced polyamide resin

“…The denture base materials can be strengthened to prevent fractures which is a common complication. There are some studies that have evaluated the effect of reinforcement of PMMA with different materials, but the those on the reinforcement of polyamide resin are scarce ( 7 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 33 ). In a previous study, the rigidity of dentures made of polyamide, polyester and conventional heat-polymerized PMMA were compared, and it was concluded that the polyamide, which has low elasticity, needed to be reinforced with metal frames ( 37 ).…”

“…Different methods have been developed to overcome these disadvantages such as; adding filling materials to reinforce of resins, chemical modifications of polymer with copolymerization and cross-linking of resin materials, producing new materials with different polymerization technics ( 6 , 7 , 8 ). Strengthening materials such as glass fiber, aramid fiber, nanodiamond powder, zirconium oxide, aluminum oxide, halloysite nanotubes, metal wires and carbon nanotubes can be added to denture base in order to increase fatigue resistance and fracture resistance of the prosthetic base materials ( 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ). However, the most effective reinforcement is yet to be determined ( 18 ).…”

Bond strength and fracture resistance of flowable bulk fill composite posts and cores in endodontically treated teeth

“…[9] The utilization of thermocycles in this study was to stimulate the degradation of the adhesive bond, created by an environment like in the mouth. [910]…”