title: The use of light-cured resin as an alternative method of occlusal splints manufacturing--in vitro study.
abstract: BACKGROUND
  Temporomandibular disorders are very common nowadays. One of the methods to treat these problems is occlusal splint therapy. Modern materials should be introduced to this treatment.
  
  
  OBJECTIVE
  The aim of this paper was to evaluate the properties of light-activated urethane dimethacrylate and the quality of the bonds it creates with thermoforming foils.
  
  
  METHODS
  Thermoforming foils were covered with light-cured resin. A bond was formed between the materials using an adhesive. A coating lacquer was used on the resin as a final preparatory step. Three laboratory tests were run: dye penetrant inspection, a Vickers microhardness test and a linear polymerization shrinkage test. The materials were layered and then cured with a polymerizing lamp emitting light of a wavelength of 400 Nm, according to the manufacturer's instructions. All the occlusal splints were fitted to upper dental arch. The devices had been made in an articulator on specially prepared gypsum models. The results were analyzed statistically using a one-sided binomial test, Spearman's rank-order correlation coefficient and the Friedman ANOVA (p=0.05).
  
  
  RESULTS
  In the dye penetrant inspection, only one sample out of sixty showed the effects of color penetration to the adhesive connection. The dye only penetrated the layer of lacquer coating the resin. The average value of the Vickers microhardness test with a load of F=50 g applied to the material surface for 30 s was HV0.05=7.43 N/mm2. The average linear shrinkage of the resin observed after polymerization was 1.175%.
  
  
  CONCLUSIONS
  Light-cured resin and an adhesive connection between the resin and thermoforming foil do not show susceptibility even to strong dye. The maximum polymerization shrinkage occurs immediately after curing. The light-cured resin that was tested seems to be a good alternative method for occlusal splints manufacturing.
authors.affiliation: Division of Dental Materials, Faculty of Dentistry, Wroclaw Medical University, Poland.
authors.forename: Mieszko
authors.initials: M
authors.lastname: Więckiewicz
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Medicine, Dresden University of Technology, Germany.
authors.forename: Klaus W
authors.initials: KW
authors.lastname: Boening
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Medicine, Dresden University of Technology, Germany.
authors.forename: Gert
authors.initials: G
authors.lastname: Richter
authors.affiliation: Department of Prosthetic Dentistry, Faculty of Dentistry, Wroclaw Medical University, Poland.
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Więckiewicz
mesh_terms: D000269:Adhesives / Q000737:chemistry; D000704:Analysis of Variance; D001840:Dental Bonding; D004867:Equipment Design; D006244:Hardness; D006245:Hardness Tests; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects*; D015233:Models, Statistical; D017090:Occlusal Splints; D010539:Permeability; D011140:Polyurethanes / Q000737:chemistry / Q000528:radiation effects*
chemical_list: D000269:Adhesives; D008689:Methacrylates; D011140:Polyurethanes; C029824:urethane dimethacrylate luting resin