title: Effect of variation of impression material combinations, dual arch tray types, and sequence of pour on the accuracy of working dies: "An in vitro study".
abstract: OBJECTIVE
  To evaluate the accuracy of dies made from dual arch impressions using different sectional dual arch trays, combinations of elastomeric impression materials, and the sequence of pour of dies.
  
  
  METHODS
  The dual arch impression materials were grouped into three groups depending on the combination of impression materials used and each group is subdivided into four subgroups. A sample size of 8 in each subgroup yielding a total 96 impressions will be made into three groups of 32 each (Group I, II, and III). Group I constitute impressions made using monophase (M) impression material, Group II constitute impressions made using combination of heavy body and light body (HL), and Group III constitute impressions made using combination of putty and light body (PL). Dies obtained were evaluated with a travelling microscope to measure the buccolingual width of the tooth at the margin by using the sharp corners of the notches as reference points.
  
  
  METHODS
  Descriptive analysis namely mean and standard deviation, one-way analysis of variance test.
  
  
  RESULTS
  The results obtained in this study indicate that though not statistically significant, the metal dual arch trays performed better when compared to the plastic trays in reproducing die dimensions.
  
  
  CONCLUSIONS
  From the results obtained, dies poured from combination of heavy body and light body impressions using plastic or metal dual arch trays showed least variation in bucco-lingual dimension from master model.
authors.affiliation: Department of Prosthodontics, CKS Theja Institute of Dental Sciences and Research, Tirupati, Andhra Pradesh, India.
authors.forename: Nagam Raja
authors.initials: NR
authors.lastname: Reddy
authors.affiliation: Department of Prosthodontics, Aditya Dental College, Beed, Maharashtra, India.
authors.forename: Jakranpally Sathya
authors.initials: JS
authors.lastname: Reddy
authors.affiliation: Department of Prosthodontics, CKS Theja Institute of Dental Sciences and Research, Tirupati, Andhra Pradesh, India.
authors.forename: Bramha Josyula Indira
authors.initials: BJ
authors.lastname: Padmaja
authors.affiliation: Department of Prosthodontics, CKS Theja Institute of Dental Sciences and Research, Tirupati, Andhra Pradesh, India.
authors.forename: Budigi Madan Mohan
authors.initials: BM
authors.lastname: Reddy
authors.affiliation: Department of Prosthodontics, CKS Theja Institute of Dental Sciences and Research, Tirupati, Andhra Pradesh, India.
authors.forename: Motupalli
authors.initials: M
authors.lastname: Sunil
authors.affiliation: Department of Prosthodontics, CKS Theja Institute of Dental Sciences and Research, Tirupati, Andhra Pradesh, India.
authors.forename: Bommireddy Tejeswar
authors.initials: BT
authors.lastname: Reddy
keywords: Dual arch impression materials; monophase impression material; putty and light body; travelling microscope