title: Mechanical properties of polyamide versus different PMMA denture base materials.
abstract: OBJECTIVE
  Polymethyl methacrylate (PMMA) resins are the most commonly used denture materials; however, they do not have a high flexural strength (FS). This study aimed to compare the mechanical properties of a polyamide-based, injection-molded denture material (Deflex) with another injection-molded PMMA base material (SR-Ivocap) and a conventional compression-molded PMMA (Meliodent).
  
  
  METHODS
  Flexural properties (deflection, bending strength, and bending modulus) of denture base materials were evaluated (n = 10). Specimens meeting International Standards Organization (ISO) specification number 20795-1 requirements were prepared (65 × 10 × 3 mm(3)). A three-point bending test was carried out on an Instron testing machine at a 5 mm/min crosshead speed. The Knoop hardness test was used to compare microhardness values. Data were analyzed using ANOVA, followed by REGWQ.
  
  
  RESULTS
  The group results, standard deviations, and statistical differences (p < 0.01) for Deflex, SR-Ivocap, and Meliodent were (A) flexural strength (MPa: 78.3 ± 1.0,(a) 69.8 ± 1.4,(b) 81.1 ± 1(a)), (B) flexural modulus (GPa: 0.70 ± 0.13,(a) 0.85 ± 0.27,(a) 1.70 ± 0.23(b)), (C) Knoop Hardness (kg/cm(2) : 7.5 ± 1.0,(a) 13.5 ± 1.4,(b) 16.9 ± 1.0(c)). Different superscript letters indicate significant difference. All Meliodent specimens fractured during flexural testing, but no Deflex specimens did.
  
  
  CONCLUSIONS
  While polyamide denture material produced good fracture resistance, its modulus is not yet sufficiently high to be equal to standard PMMA materials. Clinical Implications. Polyamide has some attractive advantages, but will require modification to produce consistently better properties than current PMMA materials.
authors.affiliation: Department of Prosthetic Dentistry, College of Dentistry, Cukurova University, Balcali, Adana, Turkey. ysanli@cu.edu.tr
authors.forename: Yurdanur
authors.initials: Y
authors.lastname: Ucar
authors.forename: Tolga
authors.initials: T
authors.lastname: Akova
authors.forename: Ipek
authors.initials: I
authors.lastname: Aysan
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003819:Denture Bases; D055119:Elastic Modulus; D004548:Elasticity; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008768:Methylmethacrylates / Q000737:chemistry; D009757:Nylons / Q000737:chemistry*; D018583:Pliability; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011312:Pressure; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D008768:Methylmethacrylates; D009757:Nylons; C077042:SR-Ivocap; D014867:Water; C091555:Meliodent; D019904:Polymethyl Methacrylate