title: Influence of working model angle on the formation of a pressure-formed mouthguard.
abstract: OBJECTIVE
  Custom-made mouthguards are fabricated on working models. However, the influence of the working model to the mouthguard characteristics has not been clearly established. The aim of this study was to examine the influence of the angle of the working model on the formation of a pressure-formed mouthguard.
  
  
  METHODS
  Mouthguard sheets of 3.8 mm ethylene vinyl acetate were pressure-formed onto working models. The angle of the working model formed by the labial surface of the central incisor and the base of the working model was set at 85°, 90°, and 95°. The thickness of the mouthguard was measured at the labial surface of the central incisor, and the buccal and occlusal surfaces of the first molar. Differences in the thickness of the mouthguards were analyzed by two-way analysis of variance.
  
  
  RESULTS
  Mouthguard thickness varied among the measured regions of the central incisors and first molars (P < 0.01). The thickness at the labial surface of the central incisor and buccal surface of the first molar was greatest for mouthguards formed using the working model with the angle set at 85° (P < 0.01).
  
  
  CONCLUSIONS
  The angle of the working model at the labial surface of the central incisor and the base of the working model should be maintained at an acute angle (e.g., 85°) to control the thickness at the central incisors and the first molars of pressure-formed mouthguards.
authors.affiliation: Department of Removable Prosthodontics, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Mizuhashi
authors.affiliation: Department of Removable Prosthodontics, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Koide
authors.affiliation: Comprehensive Dental Care, The Nippon Dental University Niigata Hospital, Niigata, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Mizuhashi
mesh_terms: D004867:Equipment Design; D006358:Hot Temperature; D006801:Humans; D003765:Models, Dental; D009064:Mouth Protectors; D011312:Pressure; D014753:Vinyl Compounds
chemical_list: D014753:Vinyl Compounds; C011566:vinyl acetate
keywords: angle of working model; mouthguard; pressure-forming