title: Effect of different impression techniques on the dimensional accuracy of impressions using various elastomeric impression materials: an in vitro study.
abstract: Production of exemplary crowns and fixed partial dentures depends upon the usage of impression material and its technique of usage that accurately reproduces prepared teeth and their relationship to the adjacent oral structure.
  
  
  OBJECTIVE
  To evaluate the linear dimensional accuracy of the elastomeric impressions using various impression techniques using different combinations of viscosities of impression materials.
  
  
  METHODS
  Crown preparation was done in a dentulous acrylic resin denture base model with six natural teeth embedded into it was made to represent the dentulous maxillary arch. A total of 55 impressions were obtained and poured in die stone using various impression techniques with different combinations of viscosities of impression materials.
  
  
  RESULTS
  Among the six techniques used, the heavy body light body two-step technique using custom tray showed the least distortion which was closely followed by the putty wash two-step technique with 2 mm spacer using stock tray.
  
  
  CONCLUSIONS
  The study revealed that the heavy body light body two-step technique with custom tray provided the best results.
  
  
  CONCLUSIONS
  Dimensional accuracy of impressions is very much required for precisely fitting of prosthesis. This study may be helpful to select the technique and materials as per clinical requirement of accuracy of impressions.
authors.affiliation: Department of Prosthodontics, Shree Bankey Bihari Dental College, Ghaziabad, Uttar Pradesh, India. drkpsingh.principal@gmail.com
authors.forename: Kishan
authors.initials: K
authors.lastname: Singh
authors.forename: Sukant
authors.initials: S
authors.lastname: Sahoo
authors.forename: K D
authors.initials: KD
authors.lastname: Prasad
authors.forename: Meenu
authors.initials: M
authors.lastname: Goel
authors.forename: Anupam
authors.initials: A
authors.lastname: Singh
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry; D003442:Crowns; D000044:Dental Abutments; D003734:Dental Casting Investment / Q000737:chemistry; D003760:Dental Impression Materials / Q000737:chemistry* / Q000145:classification; D003761:Dental Impression Technique / Q000295:instrumentation; D020724:Elastomers / Q000737:chemistry* / Q000145:classification; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D003765:Models, Dental; D020959:Polyethylene / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic; D014783:Viscosity
chemical_list: D003734:Dental Casting Investment; D003760:Dental Impression Materials; D020724:Elastomers; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane; D020959:Polyethylene; D002133:Calcium Sulfate