title: Dimensional stability and detail reproduction of irreversible hydrocolloid and elastomeric impressions disinfected by immersion.
abstract: BACKGROUND
  Because irreversible hydrocolloid impressions imbibe blood and saliva, immersion rather than spray disinfection may be more effective. Polyether has been shown to be dimensionally sensitive to immersion disinfection.
  
  
  OBJECTIVE
  The aim of this study was to determine whether irreversible hydrocolloid and polyether impressions could be disinfected by immersion without sacrificing accuracy and surface quality.
  
  
  METHODS
  Impressions were made of a master mandibular arch containing a crown preparation. Changes between the master and working casts were assessed. Irreversible hydrocolloids (Jeltrate; Palgaflex), a polyether (Impregum F), and an addition silicone (President) were used. Disinfectants were an iodophor (Biocide), a glyoxal glutaraldehyde (Impresept de), and a phenol glutaraldehyde (Sporicidin). The control was without disinfection. Casts were formed in Type IV gypsum. The roughness of working dies was also recorded and an analysis of variance was used for statistical evaluation. Results. Casts from disinfected irreversible hydrocolloid and elastomeric impressions maintained accuracy for anteroposterior and cross arch dimensions where differences from the master was less than 0.1%. Buccolingual and mesiodistal dimensions of working dies (disinfected and control) were 6 to 8 microm larger than the master for addition silicones and 11 to 16 pm for polyethers. The occlusogingival dimension of dies for control and disinfected polyether was 9 pm longer than the master compared with -3 microm for addition silicone. The range of mean surface roughness of working dies made from irreversible hydrocolloids was 1.4 to 1.7 microm and ranged from 0.5 to 0.7 microm for elastomeric impressions. Conclusion. Immersion disinfection of Jeltrate material with iodophor and Palgaflex material with glyoxal glutaraldehyde produced casts and dies as accurate as the control. Control and disinfected elastomeric impression produced dies as clinically accurate and smooth as the master. Disinfection of irreversible hydrocolloid impressions with the glyoxal and phenol glutaraldehyde produced a surface smoother than controls.
authors.affiliation: Department Restorative Dentistry, School of Dentistry, University of Washington, Seattle 98195-7456, USA.
authors.forename: G H
authors.initials: GH
authors.lastname: Johnson
authors.forename: K D
authors.initials: KD
authors.lastname: Chellis
authors.forename: G E
authors.initials: GE
authors.lastname: Gordon
authors.forename: X
authors.initials: X
authors.lastname: Lepe
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000704:Analysis of Variance; D000890:Anti-Infective Agents / Q000737:chemistry; D002133:Calcium Sulfate; D003102:Colloids / Q000737:chemistry*; D003442:Crowns; D003724:Dental Arch; D003734:Dental Casting Investment; D003737:Dental Cavity Preparation; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique / Q000295:instrumentation; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D004987:Ethers / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D006801:Humans; D007101:Immersion; D008334:Mandible; D003765:Models, Dental; D009930:Organic Chemicals; D011108:Polymers / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D012826:Silicone Elastomers / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000464:Alginates; D000890:Anti-Infective Agents; D003102:Colloids; D003734:Dental Casting Investment; D003760:Dental Impression Materials; D004202:Disinfectants; D004987:Ethers; C022821:Impregum; D009930:Organic Chemicals; D011108:Polymers; D012117:Resins, Synthetic; D012826:Silicone Elastomers; D012996:Solutions; C103320:impresept espe; C043594:Jeltrate; D005976:Glutaral; D002133:Calcium Sulfate