title: Effectiveness of Disinfectants on Antimicrobial and Physical Properties of Dental Impression Materials.
abstract: OBJECTIVE
  The aim of this study was to assess the antimicrobial activity of chemical disinfectants on alginate and silicone impression materials. The effect of chemical disinfectants on the dimensional stability of the impression materials was also assessed.
  
  
  METHODS
  For the microbiologic assessment, impressions of the maxillary arch were taken from 14 participants, 7 using alginate and 7 using an addition silicone. The impressions were divided into three sections. Each section was subjected to spraying with MD 520 or Minuten or no disinfection (control), respectively. Antimicrobial action of the chemical disinfectants was assessed by measuring microbial counts in trypticase soy agar (TSA) media and expressing the results in colony-forming units/cm2. The surface area of the dental impressions was calculated by scanning a stone cast using computer-aided design/computer-assisted manufacture and analyzing the data using a custom computer program. The dimensional stability of the impression materials after immersion in disinfectants was assessed by measuring the linear displacement of horizontally restrained materials using a traveling microscope. The percent change in length over 3 hours was thus determined.
  
  
  RESULTS
  Alginate exhibited a higher microbial count than silicone. MD 520 eliminated all microbes as opposed to Minuten. The bacterial growth after Minuten disinfection was almost twice as much for alginate than for addition silicone impressions. The chemical disinfectants affected the alginate dimensional stability. Minuten reduced the shrinkage sustained by alginate during the first hour of storage.
  
  
  CONCLUSIONS
  Alginate harbors three times more microorganisms than silicone impression material. Chemical disinfection by glutaraldehyde-based disinfectant was effective in eliminating all microbial forms for both alginate and silicone without modifying the dimensional stability. Alcohol-based disinfectants, however, reduced the alginate shrinkage during the first 90 minutes of setting. The current studies also propose another method to report the surface area based on accurate estimation by 3D image analysis.
authors.forename: Jean Karl
authors.initials: JK
authors.lastname: Demajo
authors.forename: Valter
authors.initials: V
authors.lastname: Cassar
authors.forename: Cher
authors.initials: C
authors.lastname: Farrugia
authors.forename: David
authors.initials: D
authors.lastname: Millan-Sango
authors.forename: Charles
authors.initials: C
authors.lastname: Sammut
authors.forename: Vasilis
authors.initials: V
authors.lastname: Valdramidis
authors.forename: Josette
authors.initials: J
authors.lastname: Camilleri
mesh_terms: D000328:Adult; D000464:Alginates / Q000737:chemistry; D000890:Anti-Infective Agents / Q000737:chemistry*; D001419:Bacteria / Q000302:isolation & purification; D058491:Bacterial Load / Q000187:drug effects; D017076:Computer-Aided Design; D019551:Dental Disinfectants / Q000737:chemistry*; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique / Q000295:instrumentation; D000431:Ethanol / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008422:Materials Testing; D008437:Maxilla / Q000033:anatomy & histology; D011145:Polyvinyls / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D055815:Young Adult
chemical_list: D000464:Alginates; D000890:Anti-Infective Agents; D019551:Dental Disinfectants; D003760:Dental Impression Materials; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane; D000431:Ethanol; D005976:Glutaral