The Influence of Polymerization Type and Reinforcement Method on Flexural Strength of Acrylic Resin

Abstract

The aim of this study was to evaluate the flexural strength of acrylic resin bars by varying the types of resin polymerization and reinforcement methods. Fourteen groups (N = 10) were created by the interaction of factors in study: type of resin (self-cured (SC) or heat-cured (HC)) and reinforcement method (industrialized glass fiber (Ind), unidirectional glass fiber (Uni), short glass fiber (Short), unidirectional and short glass fiber (Uni-Short), thermoplastic resin fiber (Tpl), and steel wire (SW)). Reinforced bars (25 × 2 × 2 mm) were tested in flexural strength (0.5 mm/min) and examined by scanning electron microscopy (SEM). Data (MPa) were submitted to factorial analysis, ANOVA, and Tukey and T-student tests (a = 5%) showing significant interaction (P = 0.008), for SC: Uni (241.71 ± 67.77)a, Uni-Short (221.05 ± 71.97)a, Ind (215.21 ± 46.59)ab, SW (190.51 ± 31.49)abc, Short (156.31 ± 28.76)bcd, Tpl (132.51 ± 20.21)cd, Control SC (101.47 ± 19.79)d and for HC: Ind (268.93 ± 105.65)a, Uni (215.14 ± 67.60)ab, Short (198.44 ± 95.27)abc, Uni-Short (189.56 ± 92.27)abc, Tpl (161.32 ± 62.51)cd, SW (106.69 ± 28.70)cd, and Control HC (93.39 ± 39.61)d. SEM analysis showed better fiber-resin interaction for HC. Nonimpregnated fibers, irrespective of their length, tend to improve fracture strength of acrylics.

Fracture Strength of Acrylic Resin Reinforced with Glass Fibers in Simulated Implant-Supported Overdenture Abutments

“…In addition, the present study is inconsistent with that conducted by Minami et al (36), who found no improvement in the fracture strength during their study of the repairing of heat-polymerized acrylic by reinforced self-polymerized acrylic with glass fibers. However, Fonseca et al (15) reported that there was an improvement in the fracture strength by adding glass fibers, whether in heat-or self-polymerized acrylic. The disagreement between the results of the present study and those reported by Minami et al (36) could be attributed to the difference in the position of fibers in the center of models in the former study.…”

“…However, each method has its disadvantages; for example, high-impact strength resin has poor flexural strength compared to conventional acrylic resins (14). On the other hand, metal and glass fibers exhibit different mechanical properties, high elasticity and lack of resilience (15). Fibers have been demonstrated to be more effective than metal glass, where their lower modulus of elasticity compared to metals provides more favorable stress distribution pattern (15).…”

“…On the other hand, metal and glass fibers exhibit different mechanical properties, high elasticity and lack of resilience (15). Fibers have been demonstrated to be more effective than metal glass, where their lower modulus of elasticity compared to metals provides more favorable stress distribution pattern (15).…”

“…These fibers are available in three forms: continuous parallel, chopped and woven (16,21) and have been introduced as a substitute for metals when high mechanical stresses are expected (22). Several factors influence the effectiveness of fiber reinforcement, including the quantity of fibers, their length, direction, form, position, adhesion to the polymer matrix, impregnation with the resin and type of resin (15). The greater the quantity of fibers, the greater the reinforcement effect that can be gained.…”

Influence of indirect reinforcements on the flexural strength of a thermally activated acrylic resin used for complete dentures

“…However, in cases of implant installation to retain and/or give support for complete dentures [6], TAAR present precarious mechanical properties and can frequently fracture [1][2][3]5,[7][8][9][10]. This can occur as a result of occlusal disharmony, overloading, fatigue and impact caused by accidents [11][12]. Specially during the osseointegration phase of a protocol type prosthesis, which usually presents cantilever [13], provisional prosthesis made entirely of TAAR may be used over the implants [6].…”