title: Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions.
abstract: OBJECTIVE
  This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility.
  
  
  METHODS
  Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests.
  
  
  RESULTS
  When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically.
  
  
  CONCLUSIONS
  Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In moist condition, aquasil performed significantly better than impregum. Regarding gypsum compatibility according to ADA specification, in dry condition both the materials performed almost equally, and in moist condition aquasil performed better than impregum. When tested by macroscopic evaluation, impregum performed better than aquasil in both the conditions.
authors: Department of Prosthodontics, Drs. Sudha and Nageshwara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India.
authors: Sriharsha Babu
authors: SB
authors: Vadapalli
authors: Department of Prosthodontics, Drs. Sudha and Nageshwara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India.
authors: Kaleswararao
authors: K
authors: Atluri
authors: Department of Periodontics, Drs. Sudha and Nageshwara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India.
authors: Madhu Sudhan
authors: MS
authors: Putcha
authors: Department of Periodontics, Drs. Sudha and Nageshwara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India.
authors: Sirisha
authors: S
authors: Kondreddi
authors: Department of Prosthodontics, CKS Teja Institute of Dental Sciences, Tirupati, Andhra Pradesh, India.
authors: N Suman
authors: NS
authors: Kumar
authors: Department of Prosthodontics, Drs. Sudha and Nageshwara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India.
authors: Durga Prasad
authors: DP
authors: Tadi
keywords: ADA specification no. 19; aquasil; dimensional stability; gypsum compatibility; impregum; monophase elastomers; polyether; polyvinyl siloxane; surface detail reproduction