title: Adhesion and tear energy of a long-term soft lining material activated by rapid microwave energy.
abstract: BACKGROUND
  Construction of dentures with permanent soft linings is time-consuming in the laboratory and extra costs are related to equipment and materials used.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to determine whether using microwave energy to activate the polymerization of a silicone rubber denture soft lining material affected its properties.
  
  
  METHODS
  Tear energy and adhesive properties were measured in a tensile testing machine by using a pants leg tear test and peel specimens. Tear energy was measured for specimens polymerized conventionally (control) and for 3, 5, and 10 minutes in a microwave. Data were analyzed with one-way analysis of variance and a two-sample Student t test.
  
  
  RESULTS
  The multiple comparison test failed to show a significant difference in tear energy between 3 minutes microwave activation and conventional heat curing. However, 3 minutes microwave activation revealed a significantly stronger material when compared with 5 minutes and 10 minutes (p < 0.05). Application of a two-sample Student t test failed to demonstrate a significant difference between microwave energy and conventional heat activation groups in the adhesion test. In adhesion testing, all specimens presented cohesive failure.
  
  
  CONCLUSIONS
  This method of polymerization does not compromise the strength of a soft lining material and its adhesion to polymethyl methacrylate. This study suggests the use of 3 minutes 650 W microwave energy for processing a silicone soft lining material.
authors.affiliation: Department of Prosthetic Dentistry, St. Bartholomew's and Royal London School of Medicine and Dentistry, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Baysan
authors.forename: S
authors.initials: S
authors.lastname: Parker
authors.forename: P S
authors.initials: PS
authors.lastname: Wright
mesh_terms: D000268:Adhesiveness; D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000737:chemistry* / Q000528:radiation effects; D001840:Dental Bonding; D003822:Denture Liners; D004129:Dimethylpolysiloxanes / Q000737:chemistry* / Q000528:radiation effects; D004548:Elasticity; D006358:Hot Temperature; D008422:Materials Testing; D008872:Microwaves; D011108:Polymers; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers / Q000737:chemistry* / Q000528:radiation effects; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; C020964:MDX 4-4210; D011108:Polymers; D012826:Silicone Elastomers; D019904:Polymethyl Methacrylate