title: Cast articulation accuracy using rigid cast stabilization.
abstract: OBJECTIVE
  This study evaluated the positional accuracy of casts articulated on a semi-adjustable articulator, with and without rigid cast stabilization using either laboratory plaster or mounting plaster.
  
  
  METHODS
  A reference articulation of melamine casts in maximum articulation was established and recorded in the horizontal and vertical dimensions using a verification device. The same casts were subsequently remounted 24 times using either laboratory plaster or mounting plaster. Half of the articulations from each group were stabilized using detachable mounting rods and sticky wax, and half were hand-articulated without stabilization, for a total of 6 articulations in each of 4 test groups. The resulting spatial positions established on the articulator were compared to the initial reference position on the verification device grid. Means and standard deviations of the absolute values of the horizontal and vertical displacement for each group were determined separately and compared using a one-way anaylsis of variance. Significant differences (p <0.05) were identified using Tukey's honestly significant difference multiple comparison test.
  
  
  RESULTS
  Mean vertical mandibular cast displacement ranged from 0.26 +/-0.21mm for stabilized casts mounted with laboratory plaster to 1.58 +/-0.32 mm for unstabilized casts mounted with mounting plaster. For each mounting material, significantly less vertical displacement (p <0.001) was observed with the mandibular cast stabilized before mounting. The cast mounted with laboratory plaster exhibited horizontal displacement (0.87 +/-0.29 mm) that was significantly greater than the remaining groups (p <0.001), which did not differ from each other.
  
  
  CONCLUSIONS
  Rigid stabilization of the mandibular to maxillary cast during mounting with laboratory and mounting plaster improved articulation accuracy.
authors.affiliation: Department of Restorative Dentistry, Dental School, University of Maryland, Baltimore, MD 21201, USA. rbg001@dental.umaryland.edu
authors.forename: Ronald Bruce
authors.initials: RB
authors.lastname: Gunderson
authors.forename: Sharon Crane
authors.initials: SC
authors.lastname: Siegel
mesh_terms: D000704:Analysis of Variance; D002133:Calcium Sulfate / Q000737:chemistry; D003725:Dental Articulators; D003764:Dental Materials / Q000737:chemistry; D003766:Dental Occlusion; D006801:Humans; D007574:Jaw Relation Record / Q000295:instrumentation / Q000379:methods*; D008334:Mandible; D008437:Maxilla; D003765:Models, Dental; D012117:Resins, Synthetic / Q000737:chemistry; D013223:Statistics as Topic; D014227:Triazines / Q000737:chemistry; D014716:Vertical Dimension; D014885:Waxes / Q000737:chemistry
chemical_list: D003764:Dental Materials; D012117:Resins, Synthetic; D014227:Triazines; D014885:Waxes; C011907:melamine; D002133:Calcium Sulfate